Specs Civil Works For 132kv Substations 3v1s2c

1.5.3.1.0.01-Rev.10

Civil Works for 132 kV Substations

LIST OF CONTENT FOR CIVIL WORKS INDEX SECTION

TITLE

1. 1.1. 1.2. 1.3. 1.4. 1.5. 1.6. 1.7. 1.8. 1.9.

SCOPE OF WORK General Tender Proposals Tender Conditions, Drawings, Schedule of Rates Civil Sub Contractors Method Statement Assistance to the Engineer Records Samples, Testing, Inspection Purchase from any Source

2. 2.1. 2.2. 2.3. 2.4. 2.5. 2.6. 2.7. 2.8. 2.9. 2.10. 2.11. 2.12. 2.13. 2.14. 2.15. 2.16. 2.17. 2.18.

DESCRIPTION OF THE WORKS General Site Survey and Sub-Soil Investigation Site Preparation Temporary Access Services Boundary Wall and Gates Roadways, Paving and Surfacing Drainage and Septic Tanks Foundations External Floodlighting and Emergency Lighting Buildings Cable Basements Cable Trenches Gate House Watchman's Accommodation Pump House Stairs, Steps Approval of Materials

3. 3.1. 3.2. 3.3. 3.4. 3.5. 3.6. 3.6.1. 3.7. 3.8. 3.9. 3.10. 3.11.

DESIGN OF THE WORKS Design and Drawings Liability Standards and Codes of Practice Submission of Designs and Drawings Review by the Engineer Detail Requirements for Submittals Drawings Fire Criteria Seismic Loads Road Loads Drainage Foundations

4.

SUBSOIL INVESTIGATION

5.

TRANSFORMER COMPOUNDS

6.

SETTING OUT AND TOLERANCES

7. 7.1.

EXCAVATION AND EARTHWORKS Backfill

Dubai Electricity & Water Authority

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TITLE

7.2. 7.3. 7.4. 7.5. 7.6. 7.7. 7.8. 7.9. 7.10.

Excavations Generally Excavated Materials Bottom Layer of Excavations Dewatering Filling and Reinstatement Slips and Settlements Explosives Compacted Fill Areas General Requirement

8. 8.1. 8.2. 8.3.

PILING Standards General Requirements Proprietary Piling Systems

9. 9.1. 9.2. 9.3. 9.4. 9.5. 9.6. 9.7. 9.8. 9.9. 9.10. 9.11. 9.12.

ROADS AND OTHER SURFACES General Materials Drains, Sewers and Cable Ducts Preparation of Formation Sub-base Prime Coat Bituminous Surface Interlock Paving blocks Cross fall Kerbs Footpaths and Trench Covers Stone Surfacing

10. 10.1. 10.2. 10.3. 10.4. 10.5. 10.6. 10.7. 10.7.1. 10.7.2. 10.7.3. 10.7.4. 10.8. 10.9. 10.10. 10.11. 10.12. 10.13. 10.14. 10.15. 10.16. 10.17. 10.18. 10.19.

CONCRETE Design, Materials and Workmanship Testing Cement Cement Test Certificate Cement Samples Cement Storage Aggregates Aggregates - Physical Requirements Aggregates - Chemical Requirements Aggregate Storage Aggregate Sampling Approval of Materials Water ixtures Supervision Plant Concrete Strength Requirements Concreting in hot weather Concrete Mixing Workability Transport and Placing Compaction of Concrete Vibrators


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TITLE

10.20. 10.21. 10.22. 10.23. 10.24. 10.25. 10.26. 10.27. 10.28. 10.29. 10.30. 10.31. 10.32. 10.33. 10.34. 10.35. 10.36.

Construction ts Construction Bays Curing Trial Mixes Works Test Cubes Changes in Materials or Mix Proportions Failure of Concrete to Meet Test Requirements Concrete Cores Formwork Removal of Formwork Finishes Chamfers Formed Finishes to Concrete Unformed Finishes to Concrete Surface Treatments Reinforcement Testing of Reinforcement

11. 11.1. 11.2. 11.3. 11.4. 11.5. 11.6. 11.7. 11.8. 11.9. 11.9.1. 11.9.2. 11.9.3. 11.9.4.

STRUCTURAL STEELWORKS Structural Steel Connections Design Materials Cleaning and Zinc Coating Painting Bolts Workmanship Welding Fusion Faces Butt Welded ts Intermittent Welds Testing of Welding Operators

12. 12.1. 12.2. 12.3. 12.3.1. 12.3.2. 12.3.3. 12.3.4. 12.3.5. 12.3.6. 12.3.7. 12.4. 12.4.1. 12.4.2. 12.4.3.

WATERPROOFING Generals Submittals Materials Roofing Membrane Separation Layer Insulation Board Primer Rainwater Outlet Mortar and Tiles Waterproofing of cable basement, oil/water tank, septic tank, etc. Workmanship Storage Installation Tests

13.

METALWORK

14. 14.1.

BLOCKWORK Cement


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TITLE

14.2. 14.3. 14.4. 14.5. 14.6. 14.7. 14.8. 14.9.

Sand and Aggregates Concrete Blocks Mortar for Blockwork ting Block Laying Protection Against Damage Precautions During Inclement Weather Damp Proof Course

15. 15.1. 15.2. 15.3. 15.4. 15.5. 15.6. 15.7. 15.8. 15.9. 15.10. 15.11. 15.12.

FLOOR LAYING Screeded Beds Waterproofing of gate house, pump house, staff accommodation, compound wall etc. Protection Defects Terrazzo Floors PVC Flooring Ceramic Floor Tiles Raised Flooring Alkali/Acid Resistant Floor Tiles Epoxy Resin Mortar Screed Surface hardener/dust proofer Skirting

16. 16.1. 16.2. 16.3. 16.4. 16.5.

CARPENTRY AND ERY Timber Preservative Workmanship Faults Builder's Ironmongery

17. 17.1. 17.2. 17.3. 17.4.

GLAZING General Clear Glass Wired Glass Tinted Glass

18. 18.1. 18.2. 18.3. 18.4. 18.5. 18.6. 18.7. 18.7.1. 18.7.2. 18.7.3. 18.7.4. 18.7.5. 18.7.6. 18.7.7. 18.7.8.

PAINTING Paint Emulsion Paint Oil Paints Painting of External Surfaces Wood Finishes Bituminous Paints Workmanship Storage Generally Ironmongery and Fittings Preparation of Surfaces Preparation of Paints Conditions of Applications Application of Paint Re-priming


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TITLE

18.7.9. 18.8. 18.8.1. 18.8.2. 18.8.3.

Undercoats Specific Surface Coatings Woodwork Iron and Steel Work General

19. 19.1. 19.2. 19.3. 19.4. 19.5. 19.6. 19.7. 19.8. 19.9.

DRAINAGE AND DUCTS Codes of Practice Pipes Ducts General Concrete Bed and Casings Testing Cable Ducts Manholes Manhole Covers

20. 20.1. 20.1.1. 20.1.2. 20.1.3. 20.1.4. 20.1.5. 20.1.6. 20.2. 20.2.1. 20.2.2. 20.2.3. 20.2.4. 20.2.5. 20.2.6. 20.2.7. 20.2.8. 20.2.9. 20.2.10. 20.2.11. 20.3. 20.3.1. 20.3.2. 20.3.3. 20.4. 20.5. 20.6. 21. 21.1. 21.2. 21.2.1. 21.2.2. 21.2.3. 21.2.4. 21.3. 21.3.1.

WALL AND CEILING FINISHES Plaster and Rendering Materials Cement Sand Plaster Water Lathing Bonding Agents Workmanship General Storage Mixing Lathing Bonding Agents Preparation of Backgrounds` Interaction of Materials Inspection Curing Cement Wash Workmanship Generally Wall Tiles Materials Workmanship Acid Resistant Tiles Plasterwork Suspended Ceilings Finishes Generally PLUMBING Extent of Work and General Pipes and Fitting Materials - Internal Cold Water Services NOT USED Sanitary Plumbing Drainage Rainwater Systems Pipes and Fitting Materials External Hot and Cold Water Services


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TITLE

21.3.2. 21.4. 21.4.1. 21.4.2. 21.4.3. 21.4.4. 21.4.5. 21.4.6. 21.5. 21.6. 21.6.1. 21.6.2. 21.6.3. 21.6.4. 21.6.5. 21.6.6. 21.6.7. 21.6.8. 21.6.9. 21.6.10. 21.6.11. 21.6.12. 21.6.13. 21.6.14. 21.7. 21.8. 21.9. 21.10.

Underground Drainage Pipework and Accessories Installations Traps NOT USED Taps and Fittings Insulators Valves and Cocks Rainwater Pipes and Accessories Sanitary Fittings, Materials and Equipment General Quality and Colour Wash Basins Water Closets (Asiatic) Water Closets (European) Flushing Cisterns Urinals Taps and Fittings Sundry Fittings Floor Drains Waste Water Gully Traps Water Storage Heaters Water Storage Tanks Pressure Boosting Pump Sets Builders Work Testing Cleaning Disinfection

22. 22.1. 22.2. 22.3. 22.4.

BOUNDARY WALL FENCE AND GATES Boundary Wall Fence Gate Line Termination and Sealing End Compound

23. 23.1. 23.2. 23.3. 23.4. 23.5. 23.5.1. 23.5.2. 23.6. 23.7. 23.8. 23.9. 23.10. 23.11. 23.12. 23.13. 23.14. 23.15.

LIGHTING AND SMALL POWER Scope General Standards Defects Liability Period Approvals Lighting Requirements Schedule of Design Requirements Key to Abbreviations Coding Systems Distribution Boards Miniature Circuit Breakers Cables Cable Termination Sealing and Drumming Conduit Cable Trunking Cable Trays Cable ting


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TITLE

23.16. 23.17. 23.18. 23.19. 23.20. 23.21. 23.22. 23.23. 23.24. 23.25. 23.26. 23.26.1. 23.27. 23.28. 23.29. 24.

Contractors Switches and Push buttons Lighting Fittings Lamps Socket Outlets and Fused Spur Outlets Time Switches Poles Interior Installations Exterior Installations Essential Services Emergency Lighting Portable Emergency Lighting Telephone System Schedule of Lighting Fittings and Socket Outlets Schedule of Lighting Requirements for Substations and Control Building CRANE

25.

DATA SHEET

26. 26.1. 26.2.

LIST OF REFERENCES Civil Works Lighting and Small Power


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1.

SCOPE OF THE WORKS

1.1.

General

Para (1)

Under this Section of the Contract the Contractor will be responsible for the design and construction of all civil engineering and building works and services for the following: • • • •

New 132 kV/11 kV substation. New 132 kV/22 kV substations Modification to the existing building. Civil attendance at existing sites/buildings as required.

Para (2)

The Tender must cover all requirements of the tender documents and any other items not specifically mentioned but which are necessary for the satisfactory design, construction, operation and maintenance of all equipment to the satisfaction of the Engineer. No additional costs will be considered for any items which have been overlooked but which are essential for the proper completion of the project in every respect.

Para (3)

The work shall include but not be limited to :• • • • • • • • • • • • • • •

Site survey and subsoil investigation. Site preparation, cutting or filling and levelling. Roadways, hard standing, paths and surfacing. Foundations. Substation and control buildings with cable basement. Fire Pump House. Gate House. Staff accommodation Water supply and plumbing installations. Surface water and foul drainage. Cable trenches and ducts. Air conditioning and ventilation. Lighting, small power, external floodlighting, emergency lighting and fire protection. Retaining wall Perimeter wall and gates.

Para (4)

For all substations and for individual rooms in substations suitable nameplates, signs and labels shall be provided to ensure identification, safe operation of plant and warning of danger. The text, which shall be both in Arabic and English, shall be approved by the Engineer. The substation sign board(s) shall be 3 mm Aluminium sheet powder coated and the text (Arabic & English) shall be UV resistant. DEWA logo on a separate circular plate to be fixed at the centre of signboard. The inscriptions shall be engraved with coloured lettering. All the nameplates, signs and labels shall be non-deteriorating and non-warping under aggressive weather conditions and shall be guaranteed for a minimum period of 10 years. Plates, etc., will be securely attached using bolts and nuts or screws; adhesive will not be permitted.

1.2.

Tender Proposals

Para (5)

The Contractor shall submit with his tender his proposals for all the above items, which shall conform generally to the following section "Description of the Works". Should the Contractor fail to do so then the Engineer will have the authority to reject any unacceptable later proposals.

1.3.

Tender Conditions, Drawings, Schedule of Rates


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Para (6)

The General Conditions, Tender Drawings and Schedule of Rates shall be read in conjunction with this Specification. Matters described in one are not necessarily repeated in the others.

Para (7)

The tender drawings show general layouts, architectural features and facilities to be provided. The drawings indicate the scope of the Works and tenders must comply with this, minimum requirement, however room sizes, may be increased if required to suit design and practical criteria, equipment and fittings being offered.

Para (8)

The tenderer shall visit the Substation sites in co-ordination with DEWA and consider in his offer for cutting, filling or any other ground work required for maintaining appropriate finished ground/ surfacing levels in relation to the nearby roads/buildings and as per Dubai Municipality's regulations regarding levels.

1.4.

Civil Sub-Contractor

Para (9)

The Contractor may employ a Civil Sub-Contractor or use a competent specialised section of his own organisation to carry out the Civil Works. The Sub-Contractor proposed by the Contractor shall be subject to the approval of the Engineer.

Para (10)

If the Contractor intends to sub-contract the civil engineering and building works design and/or construction, his tender must include full details of comparable works carried out elsewhere by the sub-contractor, together with details of the financial stability and general efficiency of the sub-contractor proposed.

Para (11)

The Contractor shall submit details of all key personnel to be employed on the project including positions held and curriculum vitae.

1.5.

Method Statement

Para (12)

At the commencement of the Contract the Contractor shall provide a detailed method statement. This shall include a programme giving full details of both type and quantity of all the plant he proposes to use and the order of carrying out the work.

1.6.

Assistance to Engineer

Para (13)

The Contractor shall provide and maintain upon the site to be available for use by the Engineer, all surveying instruments and testing equipment required for setting out and measuring the works and for controlling and testing the quality of materials and workmanship.

Para (14)

The Contractor shall provide all the assistance and services the Engineer may require, including labourers, chairmen and others for the purpose of checking the setting out, making tests etc.

1.7.

Records

Para (15)

The Contractor shall keep at the site accurate and up to date records and drawings of the works, and shall provide the Engineer with copies of these records. At the end of every week the Contractor shall submit to the Engineer returns of labour, plant and materials employed on the site during that week. At the conclusion of the Civil Engineering and building construction works, the Contractor shall supply reproducible copies of all drawings, showing full details of the works as constructed, including location of drains, services, foundations, roads, etc.

1.8.

Samples, Testing and Inspection

Para (16)

The Engineer may call at any time for samples of materials and workmanship proposed and these shall be furnished by the Contractor without delay. When the samples have been


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approved by the Engineer, all materials and workmanship not corresponding in quality and character with the samples will be rejected. When requested by the Engineer and before ordering materials, the Contractor shall submit for approval the names of manufacturers or suppliers proposed. When requested by the Engineer, the Contractor shall supply manufacturers test or proof certificates. If he considers it desirable, the Engineer may send inspectors to manufacturers or suppliers premises to test materials before despatch to site. Costs of all samples and testing shall be borne by the Contractor. Para (17)

Where materials or workmanship are rejected by the Engineer they must be immediately removed from the Site or demolished and removed at the Contractor's sole cost.

1.9.

Purchase from any Source

Para (18)

The Contractor shall allow in his price for the purchase of all materials etc. from any source as may be necessary to maintain the progress of the Works, to the approval of the Engineer.

2.

DESCRIPTION OF THE WORKS

2.1.

General

Para (19)

This section describes in greater detail the scope of the civil and building works and sets out any special features which are to be incorporated into the Contractor's design.

Para (20)

The requirements for quality of materials and workmanship are to be found later in this Section of this Specification.

Para (21)

The design shall comply with all codes and standards that are listed and with any others, which may be relevant. Similarly all materials, construction and tests shall comply with applicable codes and standards.

Para (22)

Due attention shall be paid in the design to all aspects including internal and external appearance, thermal and acoustic insulation, durability of materials, resistance to moisture, structural stability, fire resistance allied to means of escape in case of fire, ventilation and public health requirements.

Para (23)

The Specification Drawings show the preferred layout arrangements of plant and buildings and these shall not be changed without the written approval of the Engineer. The arrangements shown on the Specification Drawings have been based on typical sizes of plant and equipment.

Para (24)

The buildings and roads within the Site and their design and detailing shall comply with and satisfy the fundamental technical and operational requirements of the mechanical and electrical plant to be accommodated therein and with the requirements of this specification. Room sizes shall not be smaller than shown on the Specification Drawings but may be larger if necessary to meet the requirements of the plant actually being supplied and identified in the technical schedules.

Para (25)

The Contractor should ascertain for himself during the tender stage that the plant he proposes to supply will be suitable for the arrangements shown on Specification Drawings, and the Contract Price is deemed to include the cost of any enlarged buildings or modified layout to meet the Employer's design parameters. Failure of the Engineer or Employer to comment on drawings submitted by the Contractor during the tender stage which show modified arrangements not complying with Specification Drawings and design parameters shall not be accepted as approving such arrangements; any modifications proposed should be clearly stated in the Schedule of Deviations.

Para (26)

Particular attention should be given to the positioning of doors, windows and louvers to minimise the effects of sandstorms and salt laden spray and winds from the sea. Cladding, flashing and the like shall be as tightly fitting as practicable so as to exclude pollution under


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all likely local weather conditions. All external doors shall have canopy/protection and be sealed to prevent ingress of dust and wind blown rainwater, using heavy-duty seals, which shall have canopy/protection and be guaranteed for a minimum period of five years from date of commissioning. The doors and seals shall be designed so that replacement of worn seals can be achieved easily on site. 2.2.

Site Survey and Subsoil Investigation

Para (27)

The Contractor shall carry out the sub-soil investigations and in-situ or laboratory tests required to completely satisfy the design parameters he chooses for foundation or other geotechnical design. The investigation and subsequent tests shall be in accordance with BS.5930 and BS.1377 respectively.

Para (28)

Samples shall be taken as necessary and tested to determine the physical and chemical characteristics of the various strata and of the ground water, if encountered. Records of boring and trial excavations and results of tests on samples shall be incorporated into a subsoil investigation report. This shall include recommendations on the type of foundation and on the design bearing capacity of the sub-soil and shall be submitted to the Engineer for approval. The Contractor shall survey the site of the works to establish precisely the site boundaries and ground levels over the whole area. The site survey plan shall be prepared showing the survey results and the proposed layout of new works. Copies of this plan shall be sent to the Engineer.

Para (29)

The subsoil and survey information supplied to the Contractor is given in good faith but the accuracy is not guaranteed, and any variation between this information and actual site conditions will not be accepted as the basis of a claim or reason for variation of contract rates.

2.3.

Site Preparation

Para (30)

It is anticipated that though the sites will be relatively level and free from obstructions it may be necessary to provide fill to raise the ground levels to heights similar to those for adjacent buildings, sites or for the main roads.

2.4.

Temporary Access

Para (31)

The Contractor shall arrange for, construct, maintain and afterwards reinstate any temporary access required for and in connection with the execution of the works.

2.5.

Services

Para (32)

The Contractor shall be responsible for the provision of services in accordance with the Contractual General Requirements Sections of this Specification.

2.6.

Boundary Wall and Gates

Para (33)

The boundary for the Substation site shall be enclosed with a wall. The wall shall be 2.40 metres high above ground level with steel spikes.

Para (34)

Gates in the wall and fence shall comprise both main double gates and wicket gates and shall be supplied with strong lock bolts with eye padlock attachments and vertical fixing bolts.

2.7.

Roadways, Paving and Surfacing

Para (35)

Roads, parking areas, paving and surfacing within the substation compound shall be designed and constructed in accordance with the appropriate clauses latter in this section.


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Para (36)

Road layouts within the substations shall be generally as shown on the plot plan drawings attached to this Specification.

Para (37)

The Contractor's proposed site layout shall allow for vehicular access to the various items of plant and electrical equipment, for installation and subsequent maintenance. The Contractor shall ensure that the road is levelled, graded, properly compacted with appropriate rollers and surfaced, to ensure that the finished road is suitable for the maximum foreseeable imposed loads, which can be expected from vehicles transporting the various items of plant and electrical equipment. In detailing the layout of the road and parking area, special attention must be given to the manoeuvring of vehicles delivering plant, stores, spares and other materials and equipment. Road width and turning radii shall be adequate to take the largest foreseeable vehicles and equipment, which can reasonably be expected. Paving outside the plot shall be provided as per Dubai Municipality's requirements to the approval of DEWA.

Para (38)

Precast concrete paving blocks used in roads and surfacing shall comply with Dubai Municipality's Advisory Note 006 dated October 1990.

2.8.

Drainage and Septic Tanks

Para (39)

The building shall be designed to collect rainwater and discharge same through rain water down pipes. Surface water from buildings and roads shall be drained and finally discharged to an off-site natural watercourse or other off-site facility or to an external sump. The Contractor shall agree with the appropriate local authority the location and details of the final discharge points.

Para (40)

Due care shall be taken in surface water drainage design to ensure that ground erosion and flooding cannot occur, particularly around building or equipment foundations.

Para (41)

Careful attention shall be given in the design of the works to the effect that the works may have on the surface water drainage patterns of the area. Culverts shall be constructed if necessary, particularly when existing natural water channels are blocked. Drainage shall be provided where necessary to prevent ponding and to carry surface water away from buildings, structures and other works, including roads. Soak ways of adequate capacity shall be provided for storm water drainage.

Para (42)

In the absence of mains drainage system the foul drainage shall terminate at a suitably dimensioned septic tank having minimum capacity of 20 persons, which shall be of watertight construction. A soakaway of suitable size also shall be provided.

Para (43)

Drains shall be laid with regular gradients such that full flow velocity exceeds 0.75 m/sec, and manholes shall be provided at each change in direction. Drains shall be of adequate diameter and cover shall be at least 1.2 m beneath roads.

2.9.

Foundations

Para (44)

Foundations shall be capable of restricting settlements and other movements in service to acceptable limits for the equipment or superstructure to be erected thereon.

Para (45)

All foundations shall be in reinforced concrete. The minimum cover to reinforcement shall be 75 mm and the cement shall be of a type appropriate to the ground conditions. Extent of foundation for each building/structure should, unless otherwise agreed, be restricted within the periphery of the building/structure.

Para (46)

Where the ground is excavated for any reason below the underside of the proposed foundation the void shall be filled with weak concrete. External Floodlighting and Emergency Lighting

2.10.


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Para (47)

Adequate floodlighting of outdoor equipment areas shall be provided, the number and type of lights being sufficient to allow safe access and maintenance of all equipment. Emergency lighting shall be provided both inside and outside the building, to ensure the safety of maintenance personnel in the event of a power failure. Security lighting round the perimeter wall/fence and access road lighting shall be provided. Full details are specified elsewhere in the Specification.

2.11.

Buildings

Para (48)

The general layouts of buildings are to be maintained as shown, but minor modifications may be made to provide buildings wholly suitable for the equipment being provided by the Contractor to satisfy the requirements of other parts of the Specification.

Para (49)

All buildings shall be designed to have reinforced concrete frames, with infill walls of concrete block work. External walls shall be cavity concrete block work, each leaf being 100 mm minimum thickness, with 50 mm insulation and approved ties between leaves.

Para (50)

Switchgear buildings shall be designed to withstand pressure due to internal arcing or arrangement shall be made for pressure release in such an event by providing wall dampers. Parameters considered in the building design shall be subject to DEWA's approval.

Para (51)

Particular attention must be given in the design of buildings and layouts to fire prevention and safety of personnel at all times. Buildings housing switchgear and control equipment shall be designed as far as practicable to exclude pollution under all likely weather conditions. Fireproof or flame-retarding materials are to be used for floor, wall and ceiling finishes. Where areas are designed, as having a fire resistance rating then materials shall be shown to have ed approved standard tests for that class of fire resistance.

Para (52)

All floor slabs shall be constructed of reinforced concrete ed on reinforced concrete beams. Floor finishes will be designed to provide high impact and abrasion resistance. The finishes shall be in accordance with the schedule of finishes.

Para (53)

Electric overhead travelling crane(s) shall be provided in the 132 kV GIS switchgear room to facilitate erection and maintenance of the equipment. Electric hoist of adequate capacity shall be provided in 22/11kV switchgear building of multi-storeyed design.

Para (54)

A clearance of 1m between the top of equipment and any fittings suspended from ceilings shall be the criteria governing room heights.

Para (55)

Suspended ceilings, with acoustic tiling and incorporating lighting and air-conditioning fixtures shall be used in corridors, offices, toilet, control and SCADA rooms of the buildings and as per schedule of finishes.

Para (56)

External faces shall be rendered and finished with a textured undercoat and a polyurethane paint system-finishing coat of approved colour. Internal faces shall be plastered and painted. Skirting shall match the floor finish.

Para (57)

Internal partition shall be fire barriers rated for minimum 1 hr. and of approved material/design.

Para (58)

Rooms shall have walls and roof slabs adequately insulated. Thermal conductivity U (BTU/hr sq. ft. F) for rooms shall not exceed 0.1 BTU/hr sq.ft.F for wall and 0.078 for roofs. U value shall be calculated as per Dubai Municipality regulations/guidelines.

Para (59)

All 11/22 KV switchgear rooms will be air-conditioned to maintain the room temperature at 35±2ºC during summer with humidity not exceeding 70%. Winter heating is not required. All structures shall be designed to carry the loads imposed by the structure itself, together with live loads in accordance with an approved standard or code of practice.

Para (60)


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Para (61)

External doors shall be of aluminium. Internal doors shall be of painted galvanised steel of proprietary. Windows shall be aluminium framed with fixed glazing for substation buildings and having sliding shutters with aluminium grill for auxiliary buildings. Fire rated doors shall be in accordance with NFPA 80 and shall be of standard construction. Doors and windows shall be made dust-proof by use of neoprene or other approved seals. Tinted solar reflective glass shall be used in external windows. Windowsills shall be finished with approved marble cill. Attention should be paid to the provision of enough natural light in the buildings.

Para (62)

All doors opening outwards from the buildings shall be provided with panic latches or bolts, which override any locking device, for escape in the event of fire. All doors shall be provided with overhead door closures of adequate capacity. Door labels incorporating electrical hazard warning in Arabic and English shall be fixed to each entry door. Vision s shall be provided to frequently used doors.

Para (63)

Roofs to the main buildings shall be reinforced concrete slab construction, suitably insulated and waterproofed. A steel staircase with necessary landing shall be provided to permit easy access to the roof and to equipment at roof level. Roof mounted equipments if any shall be covered by approved screens for better elevation/aesthetics.

Para (64)

All roofs shall be impervious to rain and provide a rapid run-off of rainwater.

Para (65)

Special attention shall be given to the waterproofing of all roofs; sealing of all ts; allowance for thermal and shrinkage movements.

Para (66)

Roof drainage shall be constructed so that water will not enter the building in the event of blockages. Rainwater down pipes shall be external to the buildings.

Para (67)

Float operated submersible pump of capacity 25 cum/hour at a head of 8 meters to be provided for each sump of 11/22 KV and 132 KV basements. The pumps shall be fixed in all respect ready for operation and discharge into storm water drainage system.

Para (68)

The domestic water supply system shall include all plumbing, underground pipework, high and low level storage tanks, valves, fittings and pumps (including the provision of a standby pump) for the provision of a pressurised water supply system for the static water tank and all buildings within the compounds.

Para (69)

On completion of the installation and prior to putting to use, the system shall be sterilised in accordance with an approved Code of Practice.

Para (70)

The Contractor shall be responsible for the provision and installation of a water supply serving the substation buildings. Every cistern, sink, basin, etc., shall be provided with a stopcock in the supply pipe adjacent to the fitting. Each basin, sink and shower unit is to be provided with both hot and cold water. Provision shall be made for connection to the drinking water supply.

Para (71)

Toilets shall be provided with, 1 No. Asiatic type WC, 1 No. wash-hand basin, 1 No. Wallmounted mirror. WC shall be provided with a hand spray. All necessary fittings and accessories shall be provided.

Para (72)

Suitable bridge type access over cable crossings in fire escapes to be provided.

Para (73)

Battery rooms shall be supplied with sink and drainer and eye wash facility..

Para (74)

In the event of Distribution Transformers, Capacitor Banks etc. being located in the upper floor(s) having deluge/sprinkler system for fire protection, due consideration is to be given in the building design for protection of equipments housed in other areas against leakage/flooding.


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2.12.

Cable Basement

Para (75)

Cable basements, 2 m high clear below beams, shall be provided for the complete width of the substation buildings, under the switch room section. Precautions must be taken to waterproof both the walls and the floor slab to ensure that no water can permeate into the basement structure. The basement shall be divided with fire compartment barrier walls and interconnecting doors. Provisions shall be made for access from the ground floor, into various sections of the basement, via hatches and permanent ladders.

Para (76)

Drainage sumps shall be provided at relevant positions.

Para (77)

Where cables enter the building all ducts and trenches shall be sealed; the ends of all ducts entering trenches shall be bell-mouthed. The floor shall be screeded, the walls finished as per the schedule of finishes.

2.13.

Cable Trenches

Para (78)

The Contractor is responsible for all civil works required for the installation of cables. Cable entries into buildings shall be through ducts or in cable trenches. All cable runs in buildings shall be within the cable basement or in trenches, provided with checker plate covers. The covers for external cable trenches shall be of precast concrete. All cable trench covers shall be of suitable weight and size such that they may be removed or replaced by no more than two men without the use of a crane or special lifting equipment.

2.14.

Gate House

Para (79)

The Contractor shall provide with the permanent works, an enclosed shelter adjacent to the main gate of each Substation. The shelter shall have a guardroom of 4m x 4m size with a toilet/washroom. The gatehouse shall be of reinforced concrete construction with blockwork in fill partition and walls. The features of the gatehouse shall be generally similar to the substation building.

2.15.

Watchman's accommodation

Para (80)

A staff accommodation with minimum facilities as shown on the drawing shall be provided. It shall be of reinforced concrete construction with block work infill partitions walls. The features shall be generally similar to the substation building. The toilet shall be provided with 1 NO EWC, 1 NO Wash-hand basin, 1 NO wall mounted mirror and a shower tray.

2.16.

Pump House

Para (81)

The pump house shall be a single storey building near the fire water tank and shall house the fire water pumps and associated interconnecting pipework, controllers and shall have a room for the operators. The pump house shall be of reinforced concrete construction with blockwork infill s. The features of the pump house shall be generally similar to the main substation building.

2.17.

Stairs & Steps

Para (82)

Stairs to equipment rooms and loading areas shall have non slip epoxy screed finish. Threshold to doors shall be of marble.

2.18.

Approval of materials

Para (83)

The Engineer shall have the right to order that any materials, which do not meet with his approval, shall not be used in the works. The Contractor shall have the right to sample, test and give an opinion on such materials. If after this the materials are rejected by the


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Engineer they shall be removed from the site by the Contractor. Samples of materials approved shall be made available. 3.

DESIGN OF THE WORKS

3.1.

Design and Drawings

Para (84)

The Contractor shall design the civil engineering and building works and prepare complete working drawings as necessary for the construction of the works.

3.2.

Liability

Para (85)

The design of all the works shall be the responsibility of the Contractor and this Specification shall be used as the basis for the design.

3.3.

Standards and Codes of Practice

Para (86)

Civil engineering and building works and services shall all be designed and constructed in accordance with the relevant British Standard or equivalent approved Codes of Practice for the purpose of satisfying the Building Regulations of the Dubai Municipality and obtaining the necessary Building Permit approval from the Local Authority as required and provide supervision fulfilling Dubai Municipality’s requirements.

Para (87)

The Standards and/or Codes of Practice employed throughout the Works, where they do not conflict with the local by-laws, shall be of the British Standards Institution.

Para (88)

As far as practicable the standards or codes adopted shall be consistent throughout any section of the works except in meeting superior specified requirements.

Para (89)

The Contractor shall investigate the existence of any regulations and local by-laws governing the proposed works and he shall be deemed to fully comply with such requirements.

Para (90)

The Contractor shall include with his tender a schedule of standards and codes to be followed in design and construction of the works. Copies of these codes and standards shall be made available to the Engineer and Employer during the design and construction period. In the case of standards and codes not published in English, the Contractor shall obtain English translations when required and send them to the Engineer. In addition, the Contractor shall have available in his place of business (or in his supplier's works) and on site, copies in English of the relevant standards or codes used, for the sole use of the Employer and Engineer.

Para (91)

The failure of the Contractor to provide a schedule of standards and codes for his works shall be taken to mean that he intends his works to comply with the specific standards and codes referred to in this specification.

Para (92)

On completion of the project, Dubai Municipality completion certificate along with original approved drawings, Building Permit, Demarcation Certificate etc. shall be furnished to DEWA for records.

3.4.

Submission of Designs and Drawings

Para (93)

The Contractor shall be required to produce full design calculations for the foundations, building structures, building services, etc. and detailed working drawings and bending schedules, etc. He shall be responsible for the detailed designs, strength and safety of the structures, to meet the structural, acoustic and environmental requirements of the buildings and other works. He shall be responsible for ensuring that the design satisfies the requirements of all authorised local and national bodies. Design calculations and detailed drawings must be submitted to the Engineer for review before the relevant construction


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work is carried out and at least six weeks before the relevant drawing is required on site. The Contractor's programme shall allow at least 30 days for the Engineer's review and at least one revision following the Engineer's initial review. Design calculations shall be in accordance with an approved method of computation and should take of the most unfavourable combination of dead load, live load, and wind load. Live loads shall be in accordance with BS.6399 Part 1. A basic wind speed (3 set gust 1-in-50yr return period) of 45 m/s at a height of 10 m above ground level shall be assumed. The design of all buildings, structures and components shall resist wind loads calculated in accordance with British Standard 3 Chapter V, Part 2. Para (94)

The structures and all parts thereof shall be capable of withstanding within the prescribed settlement, deflection and stress limits, the worst practicable combination of dead and live loads, wind and erection forces, secondary stresses, impact, temperature and shrinkage effects except that wind and seismic forces shall not be assumed to act together.

Para (95)

All structural and secondary elements shall be designed to withstand vertical and horizontal accelerations due to an earthquake of 0.07 g.

Para (96)

Seismic design shall follow Indian Standard IS.1893.

Para (97)

The minimum design live load on all floors shall be based on the static and dynamic loadings from the equipment to be installed with due consideration for future addition/replacement with equipments of the same manufacturer but also of other standard products. Floors of the GIS room, 11/22 kV switch gear rooms and control rooms shall be designed for a minimum live load of 8KN/sqm or actual equipment load whichever is greater.

Para (98)

Submission of designs and drawings should be at regular intervals, to ensure a steady flow of submissions. Reviews may be delayed if large quantities of drawings are submitted at any one time.

3.5.

Review by the Engineer

Para (99)

Review of the Contractor's drawings or calculations by the Engineer shall not relieve the Contractor of any of his obligations to meet all the requirements of the Contract or relieve the Contractor of the responsibility for the correctness of such drawings.

Para (100)

The Contractor shall make any changes in the design, which are necessary to make the work conform to the provisions and intent of the Contract.

3.6.

Detail Requirements for Submittals Calculations

Para (101)

All calculations related to civil, structural and building work should be submitted to the Engineer in English.

Para (102)

Calculations shall clearly identify the subject of the calculations and shall include but not be limited to providing the following information: • • • • • • • • • •

Contractor's name Project name Designer's name Checker's name Contract number Name of the item Assumption used for design purposes Codes used Loadings used Date of Calculation


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• • • • • •

Calculation Reference sources Manufacturers' names and literature Reference to the appropriate drawing Technical specification section and paragraph number Control s reference all as applicable.

Para (103)

All calculations shall be on A4 size paper and shall be bound in stiff-backed ring binders. The covers shall indicate the Contractor's name, the Contract name, the title of the calculations, the date of submission and the revision letter of the calculations.

Para (104)

All computer printouts shall be bound into an appropriate binder with a cover, which shall indicate the Contractor's name, the Contract name, the title of the subject, the date of submission and revision letter of the printout.

Para (105)

Where use is made of a computer, details shall be given of the programs used and any certification of approval by independent authorities shall be given for the programs used. Use of such programs shall be to the approval of the Engineer.

3.6.1.

Drawings

Para (106)

Drawings to be used for "Construction Drawings" and record shall be prepared on A1, A3 and A4 size sheets only unless otherwise expressly approved by the Engineer.

Para (107)

Drawings and data sheets prepared by the Contractor shall include complete construction details. The drawings shall include but not be limited to the following information or detail as applicable: construction ts, reinforcement details and bar bending schedules, details for unusual or special items of formwork, special trenching, structural steel detailing, architectural drawings and schedules.

Para (108)

Specific changes shall be clearly designated on the drawings with the revision letter shown in an adjacent triangle.

Para (109)

All drawings shall be drawn, designed, checked, reviewed and signed by the Contractor before submittal.

3.7.

Fire Criteria

Para (110)

The Contractor shall make provision in the design of the building structure for minimum periods of fire resistance in accordance with "The British Building regulations 1985 - Part B - Fire - B2/3/4 Fire Spread. The designation of purpose group and type to be used for the Substation Buildings shall be `Industrial' see Table 0.1, page 6.

Para (111)

The minimum periods of fire resistance (hours) shall be related to the maximum dimensions, i.e. height, floor area or cubic capacity, of buildings or compartments of buildings as referred to in Table 6.1, page 32, under purpose group `Industrial'.

Para (112)

For calculating the maximum dimensions the following definitions shall apply: •

"Area", in relation to a building, means the area calculated by reference to its finished internal faces:

•

"Basement" means a storey of which the floor is at any point more than 1.2 metres below the finished surface of the ground adjacent to it.

•

"Floor area" means the aggregate area of every floor in a building or extension, calculated by reference to the finished internal faces of the walls enclosing the


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areas, or if at any point there is no such wall, by reference to the outermost edge of the floor. •

"Height" means the height of the building measured from the mean level of the ground ading the outside of the external walls of the building to the level of half the vertical height of the roof of the building, or to the top of the walls or of the parapet, if any, whichever is the higher.

Para (113)

To restrict the spread of fire, certain walls and floors shall be designated as fire compartment barriers. Fire compartment barriers shall provide complete barrier to spread of smoke heat and other products of combustion. The barriers shall have a rating of 2 hours minimum. All openings in walls/floors for entry/exit of cables shall be sealed with approved fire sealant rated for minimum 2 hours.

3.8.

Seismic Loads

Para (114)

The proposed works are located in an area subject to earthquakes, intensity of VII on the Modified Mercalli scale. All structural and secondary elements shall be designed to withstand vertical and horizontal accelerations due to an earthquake of 0.07g.

Para (115)

Design shall follow Indian Standard IS: 1893-1984 "Recommendations for Earthquake Resistant Design of Structures".

3.9.

Road Loads

Para (116)

The Contractor shall design the roads to an approved standard and show the design to be satisfactory for the maximum load anticipated during either the construction or operational phase of the Works.

3.10.

Drainage

Para (117)

Drainage shall be designed in accordance with relevant Codes of Practice published by the British Standards Institution, viz: BS 6031, BS 6367 and BS 8301.

Para (118)

In the neighbourhood of embankments and cuttings surface water run-off is to be controlled by the provision of lined drainage channels. Provision shall be made for the disposal of surface water from roads.

Para (119)

Surface water from roofs of buildings shall be drained to down pipes, which connect with the site drainage system.

Para (120)

The following intensities of rainfall shall be used for design of drainage: Roofs Site

75 mm/hr 15 mm/hr

Para (121)

The Contractor shall ascertain whether main foul drainage is available locally, and if so, arrangements are to be made to connect from the substation toilets into this system. Where main drainage is not available foul drainage shall terminate at suitably dimensioned septic tank having minimum capacity for 20 persons. A soakaway of suitable size also shall be provided.

Para (122)

The septic tank shall be constructed in an agreed position. The design shall be to recognised standards such as BS 6297 and approved by the Engineer. The settling compartment shall have a sloping floor and a sump for easy removal of sludge when necessary. The tank shall have separate fresh air inlet and outlet pipes and be provided with access openings. The effluent from the tank shall be drained to a soak-away pit of adequate capacity, constructed with walls of solid concrete blocks laid on their sides. The soak-away pit shall be covered by a concrete slab, with access through a manhole cover.


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Para (123)

Septic Tank and Soak ways for foul drainage as well as storm water drainage shall be located giving due consideration and with consultation/approval of the local Authorities so that in future when main sewerage/storm water drainage net work for the area is made available these services may be connected to the main line easily.

3.11.

Foundations

Para (124)

Foundations shall be designed and constructed in accordance with the recommendations of BS 8004 "Code of practice for Foundations" to safely prevent overturning, base failure, uplift and sliding. Due consideration shall be taken to the risk of detrimental deformation and settlement of the soil. Angular distortion, horizontal and vertical movements of the foundations as a result of compression of the soil, must not exceed that which is acceptable with regard to the resulting forces in the structures and the safe operation of the electrical equipment.

Para (125)

Spread foundations shall be designed such that tension or no pressure areas shall not develop under the foundations where formation level is below the natural ground water table. Extent of foundation for each building/structure should unless otherwise agreed, be restricted within the periphery of the building/structure.

Para (126)

When calculating the resistance to overturning of foundations no shall be taken of the friction between the sides of the base and the surrounding ground, unless agreed with the Engineer.

4.

SUB-SOIL INVESTIGATIONS

Para (127)

All sub-soil investigation requirements are the responsibility of the Contractor.

Para (128)

Factual reports on ground investigations attached to this document is for information only.

5.

TRANSFORMER COMPOUNDS

Para (129)

Transformers shall be placed within pens, with reinforced concrete fire and blast walls separating the transformers. Front side of the pens shall be provided as follows: •

Where access to the transformer enclosures is from within the sub station and front elevation is not prominently visible from out side, the rooms shall be enclosed with removable galvanized mesh fencing of opening size not more than 25 x 25x 3.5 mm for full height having lockable mesh access gates.

•

Where access to transformer enclosures is from outside or the front elevation is visible from outside, the front face shall be with aluminium clustra made of box section 30-x30x1.5 mm fixed in removable aluminium frames for full height. Galvanised mesh of opening size not more than 25x25x3.5 mm to be fixed behind clustra. The pattern of clustra shall be subject to approval.

Para (130)

The removable fence framing shall be designed to withstand the wind loads calculated in accordance with British Standard 3. Foundation shall be of reinforced concrete, finished in dust-proof hardwearing epoxy coating. Transformer compounds roof shall be as indicated on the drawing, provided with rainwater disposal arrangement.

Para (131)

Provision shall be made for the catchment of oil spillage and fire deluge water from the transformers resulting from mechanical or electrical failure. Precautions shall be provided to prevent pollution of streams, ground water, irrigation ditches and other watercourses by leaking or ejected oil.

Para (132)

Each transformer shall be protected from the potentially damaging consequences of a catastrophic failure in any of the transformers by providing fire/blast walls between


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adjacent transformers. Fire precautions shall be provided for the extinguishing of burning oil on entering the bond enclosing the transformer areas. Para (133)

The foundation ing the transformers shall incorporate flat-bottomed transformer tanks. Bollards to give haulage points for the transformers shall be provided at suitable locations.

Para (134)

Each transformer foundation shall be surrounded by a low wall enclosing an area in which the oil content of the transformer can be retained in the event of a major oil leak. Each area shall drain into a central oil separator tank, sized at least to hold the oil capacity of the largest transformer. The transformer bond is to be filled with 35 mm to 50 mm size cobblestones and the total volume is to be such that the voids shall contain the required oil volume of the transformer. The chippings are to finish at a level 150 mm below the top level of the oil retaining wall. A sump is to be provided in one corner of the oil pit, to facilitate removal of the oil or water by suitable pump to be provided. A gauge to indicate the level of water inside the oil water tank to be fixed at convenient location to the Engineers approval. Attention should be paid to the separation of water and oil in the sump.

6.

SETTING OUT AND TOLERANCES

Para (135)

The Contractor is responsible for the accuracy of all setting out and construction as follows: • •

Principal Setting Out ± 1 in 4500 Construction tolerances: -

Building Foundations alignment Level specific dimensions Building Framework verticality Alignment Level Concrete Work verticality Level Alignment Openings specific dimensions Mass Concrete or verticality Block Walls alignment

Max. Tolerance (mm) ±5 ±5 +25,-10 ±1:1500 ±3 ±3 ±1:1500 ±3 ±3 ±5 ±5 ±1:1000 ±5

Para (136)

The Engineer may at his discretion alter or specify new tolerances as necessary.

7.

EXCAVATION AND EARTHWORKS

7.1.

Backfill

Para (137)

Unless otherwise described, directed or permitted, fill shall consist of previous naturally occurring material, free from clay, silt and vegetable or other injurious matter and watersoluble salts harmful to copper and other metals. Filling shall be imported only from approved areas.

7.2.

Excavations Generally

Para (138)

The whole of the excavations shall be carried out to the widths, lengths and depths shown on the approved drawings and in accordance with BS 6031 and BS 8004. No unlicensed or indiscriminate digging shall be permitted.


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Para (139)

The Contractor shall allow for risk of meeting and having excavating through any sort of material including rock.

Para (140)

The Contractor may excavate by any method he considers suitable, subject to the Engineer's approval and shall allow for the use of types of plant most suited for excavation in any location and at any time.

Para (141)

The Contractor is to include for all strutting and shoring necessary for the safe execution of the works.

7.3.

Excavated Materials

Para (142)

Materials from the excavation may, if approved by the Engineer, be used by the Contractor in the construction of the Works. Other excavated material shall be backfilled where required or deposited where directed anywhere on site. Surplus materials shall be removed from the site by the Contractor and disposal as directed by the Engineer.

Para (143)

The Contractor shall at all times keep the site free from all surplus materials, rubbish and offensive matter.

7.4.

Bottom Layer of Excavation

Para (144)

The bottom of all excavated areas shall be trimmed, levelled and well rammed.

Para (145)

The bottom level of excavations or foundations shall be inspected and ed by the Engineer before foundations are constructed.

7.5.

Dewatering

Para (146)

The excavated surfaces shall be kept dry and clean by pumping or any other method deemed necessary and approved by the Engineer. Water from such dewatering shall be properly drained away from the site and disposed of off site, so as not to inconvenience s of adjacent properties or sites. Water table to be brought down to minimum 300 mm below the foundation level.

Para (147)

The cost of pumping or other dewatering shall be covered by the Contractor in his tender. No concrete, masonry, brickwork or other materials shall be placed or built until the surfaces are properly drained.

7.6.

Filling and Reinstatement

Para (148)

Filling for trenches, excavations and levelling of the site shall be deposited in layers not exceeding 250 mm uncompacted in thickness each layer watered when necessary and well rammed or otherwise consolidated to minimum 95% of the maximum dry density obtained by the use of an approved standard compaction test or to Resident Engineer's satisfaction.

Para (149)

Where excavations, whether in rock or other material, are made to a greater depth than required or ordered by the Engineer, the intervening space shall be brought up to the proper level in plain concrete.

Para (150)

Any formation, which, in the opinion of the Engineer, is not sufficiently good to carry the loads, which shall be imposed on it, shall be excavated and replaced with concrete.

7.7.

Slips and Settlements

Para (151)

Should any slips occur in the excavations, banks or filling during the execution of the works or during the Defects Liability Period from any cause whatsoever, the Contractor shall execute the necessary remedial works in such manner and form, and with such materials as the Engineer's Representative shall approve.


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Para (152)

The Contractor shall make good all settlement of filling that may occur up to the issue of the last Final Certificate.

7.8.

Explosives

Para (153)

The use of explosives shall not be permitted as a general rule. In cases where the Engineer may authorise their use and notwithstanding such authority or other conditions imposed by the Engineer, the Contractor shall remain responsible for their use including injury to any person or any damage to property, and for their safe storage. The Contractor shall make his own arrangements for the safe storage, obtaining of permits from appropriate local Authorities and for the payment of fees and licenses and all other matters connected therewith.

Para (154)

The Contractor shall employ only properly qualified workmen in the handling and firing of charges. In order to prevent injury to life and damage to property, adequate safety precautions shall be taken and proper warnings shall be given of all blasting operations. Blasting shall only take place at such times as may be approved by the Engineer.

7.9.

Compacted Fill Areas

Para (155)

In areas where excavated or imported material is to be used as compacted fill, the Contractor shall be required to achieve a density of not less than 95% of the test density for the excavated or imported material. All tests and equipment for determination and checking of the specified density shall be carried out and supplied by the Contractor in the presence of the Engineer and his price is deemed to include for this.

7.10.

General Requirement

Para (156)

Two numbers of water outlets with valve control suitable for taking one-inch water connection shall be provided just outside the main transformer cells.

8.

PILING

8.1.

Standards

Para (157)

Piling work, materials and tests shall comply with the following Codes of Practice and Standards, together with all Statutory Regulations: TITLE BS 8004 Model Specification for Piling BS 8110 BS 5328

SUBJECT Code of practice for foundations Institution of Civil Engineers Structural use of concrete Methods of specifying concrete

8.2.

General Requirements

Para (158)

The piles shall be designed to carry at least twice the working load and this shall be determined by normal design procedures.

Para (159)

The pile shall be adequately anchored into pile caps in accordance with seismic design practice.

8.3. Para (160)

Proprietary Piling Systems Where a piling system is not exclusively covered by the above specifications, the contractor shall submit to the Engineer for approval full details of the system he proposes to use. Details shall include design, suitability, case studies etc. This information shall be submitted at least 6 weeks before the use of the system is required on site.

9.

ROADS AND OTHER SURFACES


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9.1.

General

Para (161)

Substation roads and parking areas shall be properly defined compacted and paved with interlocking concrete blocks 80 mm thick. All other compound surfacing shall be stone chippings.

9.2.

Materials

Para (162)

Hardcore shall consist of natural stone or masonry broken to a 75 to 100 mm ring. It shall be free from dust, rubbish, wood, vegetable or other injurious matter.

Para (163)

Broken stone and chippings for use as site surfacing shall consist of hard crushed natural stone.

Para (164)

Bituminous wearing courses for approach roads shall be suitable for the high temperatures experienced in the area and shall comply with an authoritative and approved standard appropriate to the locality of the Work. The details and grading of the aggregate and the binder contents shall be submitted to the Engineer for approval. Sealing grit shall be applied as required.

9.3.

Drains, Sewers and Cable Ducts

Para (165)

All drains, sewers, cable ducts and other necessary work below formation level shall be completed, inspected and ed by the Engineer before the construction of any road or path is started.

9.4.

Preparation of Formation

Para (166)

The upper 300 mm of the formation shall be of suitable soil; otherwise the Contractor shall improve it to the Engineer's satisfaction or 30 CBR by blending it with granular materials such as gravel or sand.

Para (167)

The formation shall be rolled to an even and uniform surface, which shall be parallel to the finished surface of the road or path. Rolling shall be carried out with a 4 to 7 tonne power driven roller unless otherwise ordered or permitted by the Engineer.

9.5.

Sub-base

Para (168)

After the formation has been properly made, rolled and approved by the Engineer, a subbase consisting of well graded natural sands, gravels or rock or mixtures thereof shall be laid and compacted to minimum 95% of MDD, to give a finished thickness of at least 200 mm or as described or directed.

Para (169)

The material shall be free of deleterious matter and shall be well graded having grading envelop similar to table given below: BS SIEVE SIZE 75 mm 37.5 mm 10 mm 5 mm 0.6 mm 0.075 mm

PERCENTAGE BY MASS ING 100 85 - 100 40 - 70 25 - 45 8 - 22 0 - 10

9.6.

Prime Coat

Para (170)

A prime coat of 1 to 1.5 Kg/sq.m liquid bitumen shall be sprayed on in accordance with the best practice fitting to the locality of the Work.


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9.7.

Bituminous Surface

Para (171)

Two layer bituminous surfacing of 100 mm overall thickness shall be laid in accordance with the approved standard.

9.8.

Interlock Paving blocks

Para (172)

The formation and sub-base for road areas with interlock paving blocks shall be as described in Clauses 11.9.4 and 11.9.5 above. Interlock paving blocks shall be placed in a herring bond pattern on a 4 cms laying coarse of coarse sand above the sub-base.

9.9.

Cross fall

Para (173)

In the case of roads with a straight cross fall, this fall shall be not more that 1 in 40 and not less than 1 in 48. With roads to be cambered the average fall of the finished surface from the crown to the road edge shall be not more that 1 in 30 and not less than 1 in 45.

9.10.

Kerbs

Para (174)

Pre-cast concrete kerbs to BS.7263 set on a concrete bed shall be laid on each side of the roads/parking areas to define the limits for vehicular access.

9.11.

Footpaths and Trench Covers

Para (175)

Interlocking concrete block paving shall be provided for footpaths. Paving blocks shall be 60 mm thick and laid in a herring bond pattern.

Para (176)

Trench covers shall be minimum of 60 mm thick and provided with handles or holes for lifting purposes. They shall be reinforced concrete to the approval of the Engineer. The reinforcement shall be in the middle of the covers. The bearing edges of covers shall be reinforced with min. 50 x 50 x 6 mm thick hot dipped galvanised steel angle.

Para (177)

Where concrete covers are required for trenches crossing roads, these shall be designed for the heavy wheel loads expected on them and shall be specially reinforced as necessary.

9.12.

Stone Surfacing

Para (178)

Stone chippings for use as substation surfacing are to be clean hard crushed stone graded from 16 - 40 mm.

Para (179)

The formation in areas where stone chippings are to be used shall be well compacted to the approval of the Engineer.

Para (180)

Stone chippings shall be laid and lightly compacted to a minimum finished thickness of 75 mm.

10.

CONCRETE

10.1.

Design, Materials and Workmanship

Para (181)

Standards of design, materials and workmanship are to be equal to or better than those laid down in BS.8110.

Para (182)

Construction practices shall conform to the recommendations given in the CIRIA Guide to concrete construction in the Gulf Region Special Publication 31, 1984.

10.2.

Testing


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Para (183)

Tests required by the Engineer shall normally be carried out at an approved independent testing station. The cost of preparing, storing and transporting test specimens to the place of testing is to be borne by the Contractor.

10.3.

Cement

Para (184)

The cement may be Portland (BS 12), sulphate-resisting Portland (BS 4027) or super sulphated (BS 4248) depending on the soil and ground water salt concentrations. The type of cement shall be based on tables 6.1 and 6.2 of BS 8110. The cement shall be tested to determine the total alkali content in accordance with BS 4550 Part 2 or else A.S.T.M. C114-69 (Chemical Analysis of Hydraulic Cement).

Para (185)

The equivalent weight of sodium oxide shall be calculated from the following formula:-

Para (186)

Equivalent weight of Na2O = Wt. of Na2O + 0.658 x Wt. of K2O. The equivalent weight of sodium oxide shall not exceed 0.6% of the weight of cement.

Para (187)

The above restriction shall be waived if the proposed aggregate is proved without doubt to be non-reactive.

10.4.

Cement Test Certificates

Para (188)

All cement shall be certified by the manufacturer as complying with the requirements of the appropriate specification. The Contractor shall, when required by the Engineer, obtain for him the manufacturer's test certificate for any consignment as soon as possible after delivery.

10.5.

Cement Samples

Para (189)

The Engineer shall have the right to require the Contractor at any time to draw samples of cement from locations to be specified by the Engineer.

10.6.

Cement Storage

Para (190)

Cement shall be kept dry and used in rotation of deliveries. If delivered in bags, these shall be stored in a well-ventilated and weatherproof building used exclusively for this purpose. If delivered in bulk, an approved type of cement silo shall be used. Cements of different types shall be kept separately.

10.7.

Aggregates

Para (191)

Before the Engineer can approve any aggregate source the contractor shall furnish the following data: -

Para (192)

• Petrological group of rock • Rock type within the group • Shape • Surface texture • Silt content • Grading curves • Specific gravity • Impact value • Water absorption • Soundness • Salt content • Alkali reactivity The fine and coarse aggregates shall comply with BS.882, and the Clauses below, unless exceptions listed by Tenderers in the attached schedule are approved by the Engineer.


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Para (193)

The amount of material ing 75 micron (combined aggregate) shall not exceed 1.0% by wt. If dust content is more than this, it should be compensated by cement of the same amount in weight. However, dust shall not exceed 1.5% of combined aggregate.

Para (194)

The sources of all aggregates shall be approved by the Engineer.

Para (195)

Marine aggregates may be used when their chloride content complies with the clause on "Chemical Requirements" below and where the shell content does not adversely affect the workability of the concrete.

10.7.1.

Aggregates - Physical Requirements

Para (196)

The weight of voided shells in fine aggregate shall not exceed 5%.

Para (197)

The weight of the clay and fine silt fraction (smaller than A.S.T.M. sieve No.200) shall not exceed 1% by weight for coarse aggregates or 3% by weight for fine aggregates.

Para (198)

Absorption of fine and coarse aggregate shall not exceed 2.5% as measured in accordance with BS.812 or similar standard.

Para (199)

The soundness of all aggregates shall be proved by a sodium sulphate test in accordance with A.S.T.M.C88-76, from which the loss over 5 cycles shall not exceed 10% for fine aggregates or 12% for coarse aggregates.

Para (200)

The apparent specific gravity of aggregates as determined by an approved test, such as in BS.812, shall not be less than 2.5.

Para (201)

Los Angeles abrasion shall not exceed 27%.

Para (202)

Where quarries win aggregate from bedrock, especially limestone of the dolomitic type, the rock shall be checked for surface alteration to hardpan. This may affect the surface for well over a meter depth and result in salt concentrations near the surface. Such rocks are also prone to other undesirable characteristics, including pockets of clay, salt, chalk or other friable material. Rigorous initial physical inspection is essential.

10.7.2.

Aggregates - Chemical Requirements

Para (203)

Fine and coarse aggregates shall not be potentially reactive with alkalies, and shall be regularly tested in accordance with ASTM standard tests C227, C289, C342 and C586.

Para (204)

Fine and coarse aggregates shall not contain more than 0.4% by weight of acid soluble sulphates (as S03).

Para (205)

Fine aggregate shall contain no more than 0.1% by weight of chlorides (as NaC1) and coarse aggregate not more than 0.03%. Should these figures be exceeded the aggregate may still be considered acceptable in this respect provided the total sodium chloride concentration is not greater than 0.32% by weight of cement in the mix, irrespective of the origin of the chloride. Marine aggregates may be used provided that the content of chloride salt in the aggregate, expressed as the equivalent an hydrous calcium chloride percentage by weight of the cement to be used in the concrete, does not exceed 0.3%, but where the proportion exceeds 0.1% by weight of cement, marine aggregates must not be used with high alumina cement or for pre-stressed concrete in circumstances where calcium chloride ixtures are not permitted. In addition, in concrete containing embedded metal, calcium chloride must not be added in such proportion that the total anhydrous calcium chloride in the ixture, plus the equivalent value of anhydrous calcium chloride calculated from the chloride in the aggregate, exceeds 0.35% by weight of the cement. For the purposes of calculation the

Para (206)


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anhydrous calcium chloride content may be taken as equal to the sodium chloride content or to 1.6 times the chloride ion content as appropriate. 10.7.3.

Aggregate Storage

Para (207)

The aggregates shall be stored at mixer positions on drained concrete paved areas in such manner that intermingling of different sizes and types of aggregates is prevented. The stockpiles are to be protected from rubbish or windblown dust.

10.7.4.

Aggregate Sampling

Para (208)

The Engineer shall have the right to require the Contractor at any time to draw samples of aggregates from Stockpiles on the site or any other locations to be indicated by the Engineer. Testing is to be carried out at an independent laboratory approved by the Engineer.

10.8.

Approval of Materials

Para (209)

The Engineer shall have the right to order that any materials, which do not meet with his approval, shall not be used in the Works. The Contractor shall have the right to sample, test and give an opinion on such materials. If after this the materials are rejected by the Engineer they shall be removed from the site by the Contractor. Samples of materials approved shall be made available at site.

10.9.

Water

Para (210)

The water used for making concrete, mortar and grout shall be clean, fresh and free from injurious amounts of oil, vegetable or organic matter or any other deleterious substance in suspension or solution. The mix water shall be continually monitored for salt content and the concrete mix designed accordingly to limit total salt content. The water should comply with the requirements of BS.3148.

10.10.

ixtures

Para (211)

ixtures shall not be used without the approval of the Engineer. The self-retarding and water reducing ixtures where used shall be free of chlorides and consist of Lignosulphonate.

10.11.

Supervision

Para (212)

The Contractor shall employ at the Works a competent person whose first duty shall be to supervise all stages in the preparation, placing and curing of concrete. All test cubes shall be made and site tests carried out under his direct supervision.

10.12.

Plant

Para (213)

The concreting plant shall be suitable in type, capacity and design for its purpose. The performance of the plant and its disposition shall be to the satisfaction of the Engineer.

10.13. Para (214)

Concrete Strength Requirements The strength requirements for each grade of concrete proposed in the design shall be proven by means of preliminary trial tests as specified later.

Para (215)

Grades of concrete shall be in accordance with BS 5328.

Para (216)

The minimum cement content of any structural concrete for superstructure shall be 370 kg/m3. The minimum cement content for foundations and substructures shall be 400 kg/m3. The maximum cement content of any structural concrete shall be 480 kg/m3

Para (217)


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Para (218)

The maximum free-water/cement ratio shall be 0.45.

Para (219)

The maximum temperature of the fresh concrete shall be 30 C.

Para (220)

The minimum temperature of the fresh concrete shall be 9 C.

Para (221)

Mix propositions shall be calculated to give the required concrete strengths, using the method described in "Design of Normal Concrete Mixes", published by the UK Department of the Environment (1988 edition).

Para (222)

Due allowance must be made for the free water contained on surface-wet or saturated aggregates, as outlined in the above publication.

Para (223)

Where information is to be provided by the Contractor this shall be submitted, in every case, at least 14 days before the start of concrete production.

Para (224)

For designed mixes the following information shall be provided in addition to that specified in Clause 14(1) and 14(2) of BS.5328:•

Data showing that the proposed mix proportions and method of manufacture will produce concrete of the required quality with the intended workability, or

•

Details of tests on trial mixes, or

•

Statement that, for initial production where approved by the Engineer, the appropriate mix proportions given by Tables 1 and 2 in BS.5328 will be used.

Para (225)

The Contractor's designs and drawings shall show clearly the characteristic strengths, mix proportions and deviations proposed for each grade of concrete to be used.

10.14.

Concreting in hot weather

Para (226)

In hot weather concreting should be in accordance with ACI Standard 305-77 with the following additional precautions being taken: •

Mixing - In hot weather suitable means shall be provided to shield the aggregates stockpiles from the direct rays of the sun or to cool the aggregates by spraying with water and to insulate the mixing water tank and pipe lines to ensure that the temperature of the concrete when deposited shall not exceed 30 C.

•

In hot dry weather suitable means shall be provided to avoid premature stiffening of concrete placed in with hot dry surfaces. Where necessary the surfaces, including reinforcement, against which the concrete is to be placed shall be shielded from the rays of the sun and shall be sprayed with water to prevent excessive absorption by the surfaces of water from the fresh concrete.

•

Wherever possible all small pours should be carried out as late as possible in the afternoon.

10.15.

Concrete Mixing

Para (227)

All concrete except where specifically permitted by the Engineer in writing shall be supplied by an approved supplier of ready mix concrete having a microprocessor controlled batching plant. The use of truck mixed concrete shall not be permitted.

Para (228)

The concrete ingredients, classification and time of addition of water to the mix shall be recorded on the delivery ticket of each concrete batch delivered to site.


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Para (229)

In computing the quantity of water to be added, due must be taken of the water contained in the aggregates. The amount of water shall be sufficient to ensure thorough hydration, good workability and high strength.

Para (230)

The Contractor shall take all precautions to the satisfaction of the Engineer to protect the concrete from the injurious effects of the elements.

Para (231)

A cover or other suitable means shall be provided to shield the aggregate stockpiles from the direct rays of the sun or suitable means provided to cool the aggregates by spraying with fresh water and to insulate the mixing water tank and pipe lines to ensure that the temperature of the concrete when deposited shall not exceed 30 C.

10.16.

Workability

Para (232)

The concrete shall be of such consistency that it can be readily worked into the corners and angles of the formwork and around reinforcement without segregation of the materials or bleeding of free water at the surface. On striking the formwork it shall present a face which is uniform, free from honeycombing, surface crazing or excessive dusting, and which shall not, in the opinion of the Engineer, be inferior to the standards laid down in later clauses in this section.

Para (233)

The workability of concrete delivered to site shall be tested by slump test in accordance to BS.1881. The acceptable slump shall generally be 75 + _ 25 mm.

10.17.

Transport and Placing

Para (234)

The concrete shall be discharged from the mixer and transported to the Works by means that shall be approved by the Engineer and which shall prevent adulteration, segregation or loss of ingredients, and ensure that the concrete is of the required workability at the point and time of placing.

Para (235)

The concrete shall be placed in the positions and sequences indicated on the Drawings, in the Specification or as directed by the Engineer within one hour of mixing. When the site placement conditions require a longer time between mixing and pouring, suitable retarders may be used, if approved by the Engineer.

Para (236)

Except where otherwise directed, concrete shall not be placed unless the Engineer or his representative is present and has previously examined and approved the positioning, fixing and condition of the reinforcement and of any other items to be embedded, the cleanliness, alignment and suitability of the containing surfaces, and the adequacy and position of plant.

Para (237)

Inform the Engineer before each pour of concrete to allow the inspection of reinforcement and surfaces against which concrete is to be placed. A minimum of 24 hours notice shall be given in writing of the intention to place concrete. The inspection time shall be during office hours. Agreed concreting schedule shall be strictly adhered to for arranging supervision.

Para (238)

The concrete shall be deposited as nearly as possible in its final position and in such a manner as to avoid segregation, displacement of the reinforcement, formwork or other embedded items. Placing shall be continuous between specified or approved construction ts. Works shall be brought up to full thickness in 400 mm maximum compacted layers as the work proceeds.

Para (239)

Where chutes are used to convey the concrete, their slopes shall not be such as to cause segregation and suitable spouts or baffles shall be provided to obviate segregation during discharge. Concrete shall not be allowed to fall freely more than 1.5 metres except with the approval of the Engineer. Where pneumatic placers are used the velocity of discharge shall be regulated by suitable baffles or hoppers where necessary to prevent segregation or


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damage and distortion of the reinforcement, other embedded items and formwork, caused by impact. Para (240)

Concrete shall not be placed in standing or running water unless so specified or approved.

Para (241)

The concrete shall not be subject to any form of external vibration between 2 hours and 24 hours after placing. No mechanical work to recently placed concrete such as scrubbing will be permitted until 36 hours after placing of fresh concrete unless agreed otherwise by the Engineer.

Para (242)

The kickers for RCC walls shall not be less than 150 mm high and shall be cast monolithically with the base.

10.18.

Compaction of Concrete

Para (243)

The concrete shall be fully compacted throughout the full extent of the layer. It shall be thoroughly worked against the formwork and around reinforcement and other embedded items, without displacing them. Successive layers of the same lift shall be thoroughly worked together.

10.19.

Vibrators

Para (244)

Unless otherwise directed by the Engineer, approved power driven vibrators of the immersion type shall be used. They shall be inserted at such distances apart or applied in such a manner as shall ensure that the concrete is satisfactorily and uniformly compacted.

Para (245)

The Contractor shall ensure that a sufficient number of vibrators are on hand at all times giving adequate allowance for breakdown of vibrators as well as electric power failure. Vibrators shall penetrate the full depth of the layer and where the underlying layer is of fresh concrete, shall enter and revibrate that layer to ensure that successive layers are well knitted together.

Para (246)

Over-vibration, causing segregation, surface laitance or leakage through formwork, shall be avoided. Immersion vibrators shall be withdrawn slowly to prevent the formation of voids. Vibrators shall not be used to work the concrete along the forms, or in such a way as to damage formwork or other parts of the structure, or displace the reinforcement or other embedded items.

10.20.

Construction ts

Para (247)

Concreting shall be carried out continuously up to construction ts, the position and arrangement of which shall be indicated on the drawings and approved by the Engineer.

Para (248)

When not indicated on the drawings the following general rule shall apply:-

Para (249)

Columns - ts in columns are to be made at the underside of floor and at floor levels. Haunches and column capitals are to be considered as part of and continuous with the floor or roof. Floors - ts in the floor system are to be located at or near the quarter points of the span in slabs and beams, except where otherwise instructed.

Para (250)

Para (251)

Walls - Vertical ts away from corners. Horizontal ts above splays or openings.

Para (252)

Whenever the placing of the concrete is discontinued other than at the exposed faces, this discontinuity shall form a construction t. Construction ts are to be made only along a horizontal or vertical plane except that in the case of inclined or curved they shall be at right angles to the principal axis. Care shall be taken to prevent off-setting of the t and to ensure water tightness. The ts shall in every way satisfy the requirement of the Engineer, and be fully detailed on drawings prior to submission for approval.


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Para (253)

When work is resumed adjacent to a surface, which has set the whole surface, shall be thoroughly roughened. It shall be cleaned of all loose and foreign matter and laitance and washed with water immediately before placing the fresh concrete, which shall be well compacted against the t.

Para (254)

The water bars shall be provided in all construction ts below ground level in addition to any t, which may be detailed on the drawing.

10.21.

Construction Bays

Para (255)

The Contractor shall agree with the Engineer, prior to the commencement of concreting, upon the sequence of placing concrete and the positions of vertical and horizontal ts, whether shown or not on the drawings.

Para (256)

In general, slabs in excess of 6 metres in length and/or width and walls exceeding 6 metres in length shall not be poured in one operation and subsequent adjacent bays shall not be concreted within 7 days. The maximum area of any pour shall be 100 sq. m.

Para (257)

As an alternative to alternate bay construction, shrinkage gaps of up to 1 metre in width may be left at 6 metre intervals; the shrinkage gaps shall not be concreted until concrete on all sides is at least seven days old.

10.22.

Curing

Para (258)

Concrete shall be protected during the first stage of hardening from the harmful effects of sunshine, drying winds, cold, rain or running water. The protection shall be applied as soon as practicable after completion of placing by one or more of the following methods, as approved by the Engineer.

Para (259)

The concrete shall be covered by a layer of sacking, canvas, Hussein, straw mats, or similar absorbent material, or a layer of washed sand, constantly wet.

Para (260)

Alternatively after thoroughly wetting, the concrete shall be covered with a layer of approved waterproof paper or plastic membrane kept in with the concrete.

Para (261)

Except in the case of surfaces to which concrete has subsequently to be bonded, the concrete may be cured by the application of an approved liquid curing membrane. Application shall be made by low-pressure spray in accordance with the manufacturer's instructions. On vertical surfaces, the curing membrane shall be applied immediately after removing the formwork.

Para (262)

The curing of the concrete shall be maintained for at least ten days after which time the concrete shall remain covered for a further four days.

10.23.

Trial Mixes

Para (263)

The Contractor shall submit not less than 3 weeks before the commencement of manufacture of preliminary trial design mixes the following information to the Engineer in respect of each grade of concrete: • • • • • • • •

Grade of concrete Title of particular trial mix Type and grading of the aggregates Type of cement The ratio by weight of all the constituents of the concrete Type of ixture The expected compacting factor and slump Full details of the proposed site quality control


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• •

Full details of the proposed laboratory for testing. Maximum and minimum temperatures of the fresh concrete.

Para (264)

The Contractor shall also confirm his proposed testing regime and acceptance criteria for the Preliminary Trial Mixes. Should the proposals not be approved by the Engineer, then the Contractor shall comply with the paragraph on preliminary test cubes and the two following paragraphs below.

Para (265)

At least four weeks before commencing any concreting in the Works, the Contractor shall make trial mixes using samples of aggregates and cements typical of those to be used. If possible, the concreting plant and the means of transport to be employed in the Works shall be used to make the trial mixes and to transport them a representative distance. A clean dry mixer shall be used to make the trial mixes and the first batch shall be discarded.

Para (266)

Preliminary test cubes shall be taken from the proposed mixes as follows:

Para (267)

For each grade a set of 6 cubes shall be made from each of 3 consecutive batches. Three from each set of 6 shall be tested at an age of 7 days and three at an age of 28 days. The cubes shall be made, cured, stored, transported and tested in compression in accordance with approved standards and tested in an approved independent laboratory.

Para (268)

If it is proposed to use an ixture in the mix then for each grade of concrete an additional batch shall be made with a double dose of the additive. For each of these batches 3 cubes shall be made and 1 tested at 7 days and 2 at 28 days to determine the likely effect of errors in dispensing.

Para (269)

The trial design mix proportions shall be approved if the average strength of a set of 9 cubes tested at 28 days exceeds the specified characteristic compressive strength by the current margin less 3.5N/mm2. The results of the seven-day cube tests shall be used to give an indication for future use of the strengths likely to be achieved at 28 days. They shall not be used to satisfy the 28 days preliminary test cube strength requirements.

Para (270)

The current margin for each particular type of concrete mix should be determined; it may be taken as having the smaller of the values given by (i) or (ii). •

(i) 1.64 times the standard deviation of cube tests on at least 100 separate batches of concrete of nominally similar proportions of similar materials and produced over a period not exceeding 12 months by the same plant under similar supervision, but not less than 1/6 of the characteristic strength for concrete of grade 7, 10 or 15, or 3.75N/mm2 for concrete of grade 20 or above.

•

Para (271)

Para (272) Para (273)

(ii) 1.64 times the standard deviation of cube tests on at least 40 separate batches of concrete of nominally similar proportions of similar materials and produced over a period not less than 5 days but not exceeding 6 months by the same plant under similar supervision, but not less than 1/3 of the characteristic strength for concrete of grade 7, 10 or 15, or 7.5N/mm2 for concrete of grade 20 or above. Where there are insufficient data to satisfy i) or ii) above, the margin for the initial mix design should be taken as two-thirds of the concrete of grade 20 or above. This margin should be used as the current margin only until sufficient data are available to satisfy i) or ii) above. However, when the required characteristic strength approaches the maximum possible strength of concrete made with a particular aggregate, a smaller margin but not less than 7.5N/mm2 may have to be permitted for the initial mix design.

At each age of test no cube strength shall fall below the appropriate minimum specified in the Contractor's designs. Before commencing the Works the Contractor shall submit to the Engineer for his approval full details of the mixes he proposes to use, with their anticipated average strength, which must be based on the satisfactory results of these preliminary tests.


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Para (274)

The Engineer shall if he so desires be present at all preliminary tests.

Para (275)

The Contractor shall inform the Engineer of his intention to carry out such tests and the time and place of the tests at least 24 hours before they take place.

Para (276)

Neither the mix proportions nor the source of supply of materials shall be altered without the prior approval of the Engineer except that the Contractor shall adjust the proportions of the mix as required; to take of permitted variations in the materials. Such approval shall be subject to the execution, to the Engineer's satisfaction, of trial mix procedures set out herein.

10.24.

Works Test Cubes

Para (277)

For the first 10 days that a particular grade of concrete is produced, or where there is a lapse of two weeks or more between successive pours of the same grade of concrete, three samples shall be taken on each day and three cubes shall be made from each sample. Two shall be tested at 7 days and the other at 28 days.

Para (278)

After the initial 10 days, samples of designed mixes shall be taken at the reduced rate given in Table I below, with the proviso that at least one sample shall be taken on each day that concrete of that grade is used. Three cubes shall be made from each sample, one being tested at 7 days and the remaining two at 28 days.

Para (279)

Table I - Sampling rates for design mixes after initial 10 day production run of concrete grade 6 Cubes shall be made from each sample). RATE

A B

TYPE OF STRUCTURE 1

Critical Structures e.g. Masts, cantilevers Columns Intermediate Structures e.g. Beams, slabs

SAMPLE TO BE TAKEN EVERY DAY OR EVERY 10 cubic metres 40 cubic metres

Para (280)

The cubes shall be made, cured, stored and tested in compression in accordance with BS.1881. The tests shall be carried out in a testing laboratory approved by the Engineer. The laboratory must provide evidence that its equipment and procedures comply with BS.1610 and BS.1881 and that its testing machines are regularly checked and adjusted for accuracy. Full details of the qualifications of all laboratory staff shall be required by the Engineer.

Para (281)

Reports of all tests made shall be supplied direct from the laboratory to the Engineer within 24 hours of the cubes being tested. The Engineer's Representative on site shall have the authority to stop all further concrete work until acceptable test results are forthcoming.

Para (282)

Records of Test Cubes - Up to date records shall be kept by the Contractor at the works of positions in the Works of all batches of concrete, of their grade and of all test cubes, cores or other specimens taken from them. Copies of these records shall be supplied to the Engineer.

10.25.

Changes in Materials or Mix Proportions

Para (283)

Neither the mix proportions nor the source of supply of materials shall be altered without the prior approval of the Engineer, except that the Contractor shall adjust the proportions of the mix as required, to take of permitted variations in the materials. Such approval shall be s subject to the execution, to the Engineer's satisfaction, of trial mix procedures set out herein.

10.26.

Failure of Concrete to Meet Test Requirements


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Para (284)

If the strength of the specimen is less than the appropriate specified minimum crushing strength or if, in the opinion of the Engineer, the concrete fails to meet the specified requirements in other respects, the concrete in that part of the Works of which it is a sample shall be considered not to comply with the specified requirements.

Para (285)

If the specified requirements have not been met, the Contractor shall take such remedial action as may be required. Before proceeding with concreting, the Contractor shall submit for the Engineer's approval details of the action proposed to ensure that the concrete to be placed in the Works shall comply with the Specification.

10.27.

Concrete Cores

Para (286)

As and where directed by the Engineer, cylindrical core specimens shall be cut from the hardened concrete in the Works for the purpose of examination and testing. The cutting equipment and the method of doing the work shall be approved by the Engineer. Prior to preparation for testing, the specimens shall be made available for examination by the Engineer. Testing of the core shall be in accordance with approved standards.

10.28.

Formwork

Para (287)

Forms shall be designed and so constructed that the concrete can be properly placed and thoroughly compacted and that the hardened concrete shall conform accurately to the required shape, position and level, subject to the tolerances and standards of finish specified. The design/drawings for shuttering shall be submitted to the Engineer for approval before construction.

Para (288)

When concrete is to be vibrated, special care shall be taken to maintain the stability of the formwork and the tightness of the ts during vibrating operations.

Para (289)

The material and position of any ties ing through the concrete shall be approved by the Engineer. The whole or part of the tie shall be capable of being removed so that no part remaining embedded in the concrete shall be nearer the surface of the concrete than the specified thickness of cover to the reinforcement. Any holes left after the removal of ties shall be filled, unless directed by the Engineer, with concrete or mortar of approved composition.

Para (290)

Where concrete is to be poured in successive lifts care shall be taken to ensure that the formwork is set tightly against the concrete of the preceding lift to prevent the formation of lips and loss of grout or liquid between the formwork and the concrete.

Para (291)

The formwork shall be inspected and certified by the specialist regarding stability/safety.

10.29.

Removal of Formwork

Para (292)

All forms shall be removed without damage to the concrete. The use of mould oil or other material to facilitate this shall be subject to the approval of the Engineer.

Para (293)

Before soffit forms and props are removed the concrete shall be exposed by removal of the side forms or otherwise as required by the Engineer, in order to ensure that it has sufficiently hardened. The forms shall not be struck until the concrete has reached a cube strength of at least twice the stress to which the concrete may be subject at the time of striking. The formwork to vertical surfaces may be removed after 24 hours in normal weather conditions (over 15 C).

Para (294)

All form work for pits, ducts and holding down boltholes must be so constructed that it can be easily collapsed to facilitate withdrawal after the initial set of the concrete.

Para (295)

The Contractor's proposed method for the construction and fixing of the formwork for bolthole pockets shall be submitted to the Engineer for approval before construction. The


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top of the shuttering shall be suitably covered to prevent entry of excess grout, materials used for curing etc. Para (296)

Solid timber must not be used for forming holding down boltholes. Bolthole formers may be made of plywood, expanded metal, polystyrene or other method approved by the Engineer, who may require the Contractor to carry out a test pour, using the proposed bolthole former. Minimum Period before Striking Formwork. TYPE OF FORMWORK

Vertical sides of beams, walls, columns, lift not exceeding 1.2 m. Vertical sides of beams, walls, columns, lift exceeding 1.2 m. Soffit of main slabs and beams, (props left under) Removal of props - beams and main slabs and other work Cantilever beams and slabs

MINIMUM PERIOD BEFORE STRIKING OPC SRC 24 hours 36 hours 36 hours

60 hours

7 days 18 days 21 days

8 days 19 days 21 days

10.30.

Finishes

Para (297)

The Contractor shall state precisely on his plan which of the types of finishes described hereunder he intends to use in the various locations. Any defective concrete finish will be rejected. The Engineer may at his discretion order the defects to be cut out and made good.

Para (298)

Plastering of defective concrete, as a means of making good will not be permitted, except that in the case of minor porosity on the surface the Engineer may approve a surface treatment by rubbing down with cement and sand mortar of the same richness as in the concrete. This treatment shall be made immediately after removing the formwork.

10.31.

Chamfers

Para (299)

All exposed edges and exposed internal angles of concrete structures shall have chamfers of minimum dimension 20 mm x 20 mm unless required by the design to have larger splays.

10.32.

Formed Finishes to Concrete

Para (300)

Type F.1 - This finish is for surfaces against which backfill or further concrete will be placed. Formwork shall consist of sawn boards, sheet metal or any other suitable materials, which will prevent the loss of grout when the concrete is vibrated.

Para (301)

Type F.2 - This finish is for surfaces, which are normally exposed to view but where the highest standard of finish is not required. Forms to provide Type F.2 finish will be faced with wrought and thickened boards with square edges arranged in a uniform pattern. Alternatively, plywood or metal s may be used if they are free from defects likely to detract from the general appearance of the finished surface. ts between the boards and s shall be horizontal and vertical unless otherwise directed. This finish shall be such as to require no general filling of surface pitting but fins, surface discolouration and other minor defects shall be remedied by methods approved by the Engineer.

Para (302)

Type F.3 - This finish is for surfaces prominently exposed to view where good appearance and alignment are of special importance.

Para (303)

To achieve this finish, which shall be free of board marks, the formwork shall be faced with plywood or equivalent material in large sheets. The sheets shall be arranged to coincide with architectural feature, cills, window heads or drainages in direction of the surface. All ts between s shall be vertical and horizontal unless otherwise directed. Suitable ts shall be provided between sheets to maintain accurate alignment in the plane of the sheets. Unfaced wrought boarding or standard steel s will not be permitted for Type


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F.3 finish. Permanent forms shall be constructed of slabs or blocks or precast concrete, natural stone, brickwork or other approved material as directed. Such slabs or blocks shall have an exposed surface of the quality shown on the Drawings and as specified. They shall be fixed to the structure by approved means and the ts between them shall be made tight with mortar or other means of preventing leakage. The use of internal metal ties shall not be allowed. 10.33.

10.33 Unformed Finishes to Concrete

Para (304)

Type U.1 - This is a screeded finish for surfaces of foundations, beds, slabs and structural to be covered by backfills, subsequent stages of construction, bonded concrete, topping or cement mortar beds to receive paving and on exposed surfaces or paving where superior finish is not required. It is also the first stage for finishes U.2 and U.3. The finishing operations shall consist of levelling and screeding the concrete to produce a uniform plane or ridged surface, surplus concrete being struck off by straight edge immediately after compaction.

Para (305)

Type U.2 - This is a floated finish for surfaces of beds and slabs to receive mastic pavings or block or tile pavings where a hard smooth steel-trowelled surface is not required. Floating shall be done only after the concrete has hardened sufficiently and may be done by hand or machine. Care shall be taken that the concrete is worked no more than is necessary to produce a uniform surface free from screed marks.

Para (306)

Type U.3 - This is a hard smooth steel-trowelled finish for surfaces of concrete pavings; tops of walls; exposed surfaces of equipment foundations and in the vicinity of holding down bolt chases; copings and other exposed to weathering; surface beds and slabs to receive thin flexible sheet and tile pavings bedded in adhesive and seating for bearing plates and the like, where the metal is in direct with the concrete. Trowelling shall not commence until the moisture film has disappeared and the concrete has hardened sufficiently to prevent excess laitance from being worked to the surface. The surface shall be trowelled under firm pressure and left free from trowel marks.

10.34.

Surface Treatments

Para (307)

Where concrete is to be treated with sodium silicate or a similar dust preventive coating, this must be carried out within 14 days of the concreting of the foundation and be applied in accordance with the manufacturer's instructions.

Para (308)

All concrete surfaces in with Earth, including underside of foundations shall be protected with a 4 mm thick SBS bituminous torch applied membrane with protection installed as per manufacturer's detail and instruction.

10.35. Para (309)

Reinforcement Mild steel and high yield steel bars and steel fabric shall comply with relevant approved standards. Foundation and substructure reinforcement shall be deformed bars. Test certificates for each consignment delivered shall be supplied by the Contractor.

Para (310)

Reinforcement shall be stored clear of the ground on sufficient s to prevent distortion of the bars. Mild steel and high tensile steel are to be stored separately.

Para (311)

Reinforcement shall be bent cold by approved means to the dimensions shown on approved bending schedules.

Para (312)

All reinforcement shall be free from oil, grease, paint, dirt, loose scale or rust at the time of concreting.

Para (313)

Reinforcement shall be rigidly fixed in the positions shown on approved drawings, using soft pliable annealed steel coated binding wire of 1.6 mm diameter, to prevent movement


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during concreting and to maintain the specified cover to bars. Chairs and concrete spacer blocks shall be provided as required to achieve the designed bar arrangement. Para (314)

All exposed steel shall be protected from corrosive effects of humidity water and dust.

Para (315)

All reinforcement having surface rust, which does not reduce the size of the bar, shall be blast cleaned with proprietary grit immediately prior to concreting.

Para (316)

Concrete cover to reinforcement shall be: All surfaces in with earth: Superstructure and internal surfaces:

75 mm 40 mm

10.36.

Testing of Reinforcement

Para (317)

The Engineer shall have the right to select at any time samples of steel reinforcement for testing in accordance with the relevant approved standard.

11.

STRUCTURAL STEELWORK

11.1.

Structural Steel

Para (318)

Structural steel shall be of Grade 43 A in accordance with BS.4360 or an equivalent approved standard and shall be fabricated from new sections unless otherwise specified and agreed in writing by the Engineer.

11.2.

Connections

Para (319)

Shop connections shall generally be electric arc welded or bolted. Site connections shall be bolted as shown on the drawings unless specifically approved by the Engineer.

11.3.

Design

Para (320)

The preparation of design calculations in accordance with the requirements of this Specification shall include the computation of stresses in all structural components and shall show how all loads are transferred to the foundations.

Para (321)

Consideration shall be made in sizing to eliminate excessive deflection or vibration during service. Suitable stress reductions shall be applied to slender compression in accordance with BS.449 or equivalent approved standard.

11.4.

Materials

Para (322)

Samples of all materials shall be tested and copies of the test reports giving physical and chemical properties issued to the Engineer for approval. These tests shall prove the compliance of the material for the purpose intended in accordance with the approved standard. Where tests are carried out by an independent laboratory, the source of origin of the material shall be stated and if different sources of supply are contemplated, additional tests shall be carried out. All materials shall be offered for inspection before and after galvanization, prior to painting.

11.5.

Cleaning and Zinc Coating

Para (323)

The whole of the steelwork shall be blast cleaned to remove all rust, grease and mill-scale, then zinc coated before despatch to site as follows:•

Galvanising - Steel items to be galvanised shall be so treated after all cutting, drilling, punching and removal of burrs has been carried out. Galvanising shall be applied by the hot dip process and shall consist of zinc weighing not less than 610 g/sq.m of


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surface. The zinc coating shall be smooth, clean, of uniform thickness and free from defects. The preparation for galvanising itself shall not adversely affect the mechanical properties of the steel. The testing of the zinc coating on galvanised articles shall be carried out in accordance with BS 729. 11.6.

Painting

Para (324)

All steel structures including galvanised elements shall be painted in accordance with the specifications in the subsection for painting. The galvanised components shall be cleaned and receive a coat of etch primer in lieu of blast cleaning prior to the application of the specified paint system.

11.7.

Bolts

Para (325)

The bolts connecting galvanised shall be hot dip galvanised, cium plated, rust-proofed by some other approved process or of stainless steel.

11.8.

Workmanship

Para (326)

Fabrication and erection shall conform at all stages to the BS.444 or equivalent standard approved by the Engineer.

11.9.

Welding

Para (327)

Welded construction shall be carried out in workshops under approved conditions by experienced operators and where continuous supervision is exercised. Machine welding will be allowed where approved machines are in use, correctly controlled by qualified operators.

Para (328)

Where the Engineer approves site welding, this shall not be done under weather or other conditions, which might adversely affect the efficiency of the welding, and, where necessary, effective protection and other safeguards, as shall be agreed with the Engineer, shall be provided.

Para (329)

Welding Procedure - Details of the proposed welding procedure accompanied by a diagram showing the build-up of all main welds, together with the details of the manufacture, classification, code and size of electrodes to be used, shall be submitted to the Engineer for his approval.

Para (330)

Welding shall be such that distortion is reduced to a minimum, and local distortion is rendered negligible in the final structure.

Para (331)

Butt welds in flange plates and/or web plates shall be completed before the flanges and webs are welded together.

Para (332)

Approval of the welding schedule and procedure shall not relieve the Contractor of his responsibility for correct welding and for the minimising of distortion in the finished structure.

Para (333)

All welds shall be finished full and made with the correct number of runs, the welds being kept free from slag and other inclusions, all adhering slag being carefully removed from the exposed faces immediately after each run.

11.9.1.

Fusion Faces

Para (334)

Fusion faces, angle of bevel, root radius and the like shall be properly prepared to give the approved weld forms. The fusion faces shall be carefully aligned and the correct gap and alignment maintained during the welding operation. In the preparation of the fusion faces, shearing shall be limited to metal thicknesses not greater than 8mm. All fusion faces shall


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be prepared by machining, or where approved, by the use of special flame cutting apparatus. Faces shall be kept clean and protected. 11.9.2.

Butt Welded ts

Para (335)

All main butt welds shall have complete penetration and, except on tubes where it is impracticable, shall be welded from both sides, the back of the first run being suitably gouged out.

Para (336)

The ends of the welds shall have full throat thickness. This shall be obtained on all main welds by use of extension pieces adequately secured on either side of the main plates. Additional metal remaining after the removal of the extension pieces shall be removed by machining, or by other approved means, and the ends and surfaces of the welds shall be smoothly finished.

11.9.3.

Intermittent Welds

Para (337)

Intermittent weld shall not be permitted. All welds shall be continuous on both faces to ensure a proper seal against ingress of corrosion.

11.9.4.

Testing of Welding Operators

Para (338)

Only welding operators who satisfy the appropriate tests shall be employed on welding. Should an operator fail in a first test, two further tests shall be undertaken immediately and the operator to qualify must satisfactorily both these tests.

12.

WATERPROOFING

12.1.

General

Para (339)

The roof waterproofing shall comprise of 4 mm thick APP bitumen membrane with nonwoven polyester reinforcement of minimum 260 gm./sqm. torch applied laid over the concrete cast to slopes with extruded polystyrene insulation board of minimum density 35 kg/cum , separation layer followed by mortar and concrete tiles.

Para (340)

Areas of suspended slabs for toilet/kitchen shall be sunken and waterproofed with two layers of 4 mm thick SBS modified bituminous membrane separated with minimum 50 mm mortar to the Engineer's approval.

Para (341)

For waterproofing of basements and underground tank the structures shall be designed to the requirements of BS 8007 and tanked externally with 4 mm thick SBS modified bituminous membranes having non-woven polyester reinforcement of minimum 260 gm.sqm. All other independent substructures shall be protected with two coats of bitumen coating and protected with 1000 gauge polythene sheet. The membrane shall be protected from damage during construction activities by a sand cement screed, protection board as necessary.

Para (342)

All components of the system shall be preferably obtained from a common source. The application of the waterproofing system shall be carried out by manufacturer's standard applicators strictly in accordance with the manufacturer's instructions.

Para (343)

The waterproofing system shall be guaranteed for 10 years for material, workmanship and other liabilities, which may be caused by leaks/failure of the system. The guarantee provided by the Contractor shall be ed by roofing manufacturer's insurance guarantee for a similar period.

12.2.

Submittals

Para (344)

The Contractor shall make the following submittals to the Engineer for approval: -


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•

Manufacturers details/specifications for the material including the standard details for terminations, penetrations, flashings and bonding together with the installation procedures.

•

Shop drawings indicating the side/end laps, and particular details for flashings and drainage.

•

Particulars of the applicator recommended by the manufacturer.

•

Format of Guarantee.

12.3.

Materials

12.3.1.

Roofing Membrane

Para (345)

A 4 mm thick APP bituminous reinforced membrane, reinforced with a minimum 260-g/sq. m. stable non-woven polyester, finished on both sides with a macroperforated torch off film allowing laying by torch. The laps are to be fully torched and seamed.

12.3.2.

Separation Layer

Para (346)

A 100 gm/sq.m. geotextile separation layer such as Terram, Typar, Bidin/equivalent.

12.3.3.

Insulation Board

Para (347)

The insulation boards to be used shall be extruded polystyrene, 35 Kg/m3 density.

12.3.4.

Primer

Para (348)

The primer to be used shall comply with all respect to ASTM D 41 and shall be applied at a minimum rate of 250-300 g/sq.m.

12.3.5.

Rainwater Outlets

Para (349)

They shall consist of a prefabricated flange and a welded pipe, flange dimension exceeding 120 mm from edge of pipe opening. Pipe shall be of a diameter and a length adopted to the roof condition. Outlets shall be PVC or aluminium to the Engineer's approval. All flanges shall be primed on both faces before insertion in the roofing built-up. Bottom of the pipe shall be sealed to the downpipe entry.

12.3.6.

Mortar and Tiles

Para (350)

Mortar and Tiles as specified in relevant subsection.

12.3.7.

Waterproofing of Cable Basement, Oil/Water Tank, Septic Tank, etc.

Para (351)

The basement shall be waterproofed using preformed SBS modified bituminous membranes. The membrane below the structures shall be a minimum of 4mm thick and shall be reinforced with non-woven polyester/fibre glass and shall have an anti-rupture polyester film surfacing. The membrane shall be applied with a minimum of 150mm laps, which shall subsequently be torched. The application shall follow the instructions given by the manufacturer. Details of waterproofing at sleeves/cable entries shall be to Engineers approval. Membrane in contract with backfill shall be protected against damages by approved protection system i.e., protection board and/or screed, etc., depending on site condition.

12.4.

Workmanship


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12.4.1.

Storage

Para (352)

All materials shall be stored in dry area, out of direct sunlight and according to manufacturer's instructions (correct rolls position, maximum load and stacking allowed).

Para (353)

In the opinion of the Engineer, if the stored materials are damaged or otherwise rendered unusable due to inadequate and poor storage, they shall be removed from site as instructed and replaced at no extra cost to the Employer.

12.4.2.

Installation

Para (354)

The installation shall be by approved applicators and supervised by the manufacturer of the waterproofing system.

Para (355)

The tiles shall be laid on a bed of 4 cm thick cement sand mortar with appropriate expansion ts.

12.5.

Tests

Para (356)

The roofing membrane shall be tested by flooding with water with a minimum 50 mm height for 36 hours.

Para (357)

The test shall be repeated after completion of tiling and related ancillary works.

13.

METALWORK

Para (358)

All metals and metalwork components whether fabricated on or off site shall conform to the requirements of the relevant British Standards.

Para (359)

Metalwork articles shall have a first class finish, and be free from scale, rust, damage or other defects.

Para (360)

Components shall be properly assembled and ted in a neat and functional manner. Welded connections shall be ground off as necessary to present a clean smooth finish without detriment to the strength of the connection.

Para (361)

Particular attention shall be given to the protection of metalwork from degradation caused by the environment in which it is to be used. This shall be accomplished by galvanising, surface coating or such other treatment suitable for the metalwork under consideration.

Para (362)

Checker Plate - Checker plate trench covers to be mild steel of adequate thickness to suit span and loading conditions; finished with a paint system specified for steel structures in the subsection for painting in light grey colour.

Para (363)

Tubular Hand railing - Where used shall be 42.4 mm outside diameter and minimum 4 mm thick. Handrails and standards shall be hot-dip galvanised and painted as per relevant subsection of the specification. A 10mm thick, 150mm high kick plate shall be fixed to the standards.

Para (364)

Ladders - Access ladders/stairs are to be galvanised mild steel and shall comply with the requirements of BS 4211.

Para (365)

Aluminium - Aluminium alloy shall be of a composition applicable to the function of the finished product and conform to BS 1470, or BS 1474.

Para (366)

The aluminium components shall be left with a plain mill finish or with a plated, enamelled, lacquered, polyester powder coated or anodised finish as required under the Contract.


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Para (367)

Aluminium Windows, Doors, Screens and Louvres - Extruded box profiles for door, window, or screen frame sections shall have an average wall thickness of not less than 1.8mm. Aluminium sections shall be compatible with approved ironmongery.

Para (368)

Glazing beads, hinges, and other fittings shall be designed to match 'en suite' with the main frame profiles.

Para (369)

Frame corners shall be mitred and coupled together with solid aluminium corner blocks and sealed and secured by pressure crimping.

Para (370)

Mechanical ts shall be field caulked on the inside prior to installation.

Para (371)

Welded ts shall be made in the factory and finished smooth and flush.

Para (372)

Aluminium door, window or screen frames shall be 'non-structural' in of the fabric of the main building.

Para (373)

The frames shall be so designed as to place no reliance on the glass to provide rigidity to the assembled components.

Para (374)

All framing, glazing and structural elements in connection with windows, doors and screens shall be capable of withstanding the wind loads specified.

Para (375)

Aluminium sections shall be polyester powder coated or in colours to be selected. Average thickness of polyester powder coating shall be 40 microns.

Para (376)

Steel Doors - Steel doors shall be of standard manufacture approved by the Engineer. The doors shall be manufactured in accordance to BS 6510 or equivalent approved standard except for fire rated doors which shall comply with the requirements of NFPA 80.

Para (377)

The doors shall be insulated and protected by galvanising and application of epoxy paint system to the approval of DEWA.

Para (378)

Other Materials - Materials not herein fully specified and which may be offered for use in the Works shall be first class quality and of such kind as is generally used in first class work. The Engineer shall have the right to determine whether all or any of the materials offered or delivered for use in the works are suitable for the purpose.

14.

BLOCKWORK

14.1.

Cement

Para (379)

Cement shall be of a quality as described in the section for Concrete. The clause in that section referring to cement storage shall also apply.

14.2.

Sands and Aggregates

Para (380)

Fine and coarse aggregates for forming blocks shall be aggregates from neutral sources of hard durable material or other approved, free from deleterious substances.

14.3.

Concrete Blocks

Para (381)

Precast concrete blocks shall be in accordance with BS 6073 and shall have a compressive strength of 7N/sq. mm average for 10 blocks calculated on the gross area of block. Minimum strength of individual block 6N/sq.mm. Blocks must be thoroughly cured before laying.

14.4.

Mortar for Blockwork


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Para (382)

Mortar for use with blockwork shall be mixed in proportions appropriate to the strength and permeability of the building block used and to the degree of exposure of the finished work. Mortar shall be mixed mechanically. The ingredients shall be mixed thoroughly in the required proportions, first dry and then with the addition of water until a uniform colour and suitable consistency is obtained. The mortar shall be used within 2 hours of the addition of the mixing water and any mortar not then used shall be discarded.

Para (383)

Cement for mortar shall comply with the requirement of BS 12 and sand shall be naturally occurring type complying with BS 1200. Plasticisers shall be added to mortars only after Engineer has approved its use in writing and shall be used in accordance with the recommendations of the manufacturer.

14.5.

ting

Para (384)

External wall faces shall be ed with an approved t, faces of walls which are to be plastered or rendered shall have their ts raked out to form key. All other wall faces and partitions shall be flush ted. All ting shall be completed with pointing as the work proceeds.

14.6.

Block Laying

Para (385)

All blocks shall be kept damp during building and shall be laid on a full bed of mortar. All ts shall be completely filled with mortar. Sealed movement ts shall be formed where necessary. The installation shall be as per BS 5628.

Para (386)

Blockwork shall be built in a uniform manner in truly level courses and truly vertical or battered. Corners and other advanced work shall be racked back and not raised above the general level more than one metre. Toothing shall be used only where provision has to be made for a future extension.

Para (387)

Where so described or directed, reveals and piers, together with air bricks, fixing bricks for ter's other work and other relevant items shall be built in as the work progresses.

Para (388)

Walls shall be constructed with an approved mesh reinforcement every second course.

Para (389)

Cavity wall shall be constructed with cavity of 50-75mm in width.

Para (390)

Wall ties shall be laid sloping downwards towards the exterior. The ties shall be spaced at 900 mm horizontally and 450 mm vertically, or equivalent to suit the block sizes.

Para (391)

Additional wall ties shall be provided at the sides of openings every 300 mm vertically for brick and 200 mm vertically for block.

Para (392)

Weep holes shall be built into the external skin of cavity walls in the form of sand filled vertical ts at 1 m centres and are to be raked out on completion. Weep holes shall be placed over all lintels, dpc or other significant obstructions to the cavity.

Para (393)

Where shown on the drawings and at the jambs of all openings hollow concrete blocks shall be filled with weak concrete, well tamped down and carried from base slab to top of such openings.

Para (394)

Where the blocks abutt reinforced concrete columns and where indicated elsewhere, the blocks shall be tied to the columns every second course by means of approved galvanised ties fixed to the columns.

Para (395)

Holes and chases shall be cut out or left in the walls as required and provision shall be made for making good to the satisfaction of the Engineer.

Para (396)

All cavity walls shall be filled with approved insulation (polyurethane or equivalent).


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Para (397)

On completion, all blockwork shall be cleaned down and mortar dropping and other marks removed. Defective blocks or workmanship shall be made good.

14.7.

Protection Against Damage

Para (398)

Architectural features, finishes, surfaces and quoins shall be protected against damage during the progress of the works. Sills, jambs and heads shall be protected by casings as soon as built.

14.8.

Precautions During Inclement Weather

Para (399)

Newly laid blockwork shall be protected from the harmful effects of the sunshine, rain, drying wind, running or surface water and shocks. Any work that may be damaged shall be taken out as directed and pointed out by the Engineer. Any costs incurred in carrying out such remedial work shall be borne by the Contractor.

14.9.

Damp Proof Course

Para (400)

A damp proof course of fibre based bitumen sheeting complying with BS 6398 shall be laid under walls above ground level so as to exclude rising moisture.

15.

FLOORLAYING

15.1.

Screeded Beds

Para (401)

Concrete floors which are required to be surfaced with screed shall have a roughened surface, produced by hacking and wire brushing. The roughened concrete floor shall be cleaned, wetted preferably overnight, the surplus water removed and 1:1 cement/sand grout brushed into the surface, keeping just ahead of the screeded bed. The screeded bed shall be 80 mm minimum thick and shall be well compacted and levelled with a screeding board and steel trowelled smooth. If the screed is the finished surface it should be treated with an approved silicate of soda solution hardener to prevent dusting.

Para (402)

The screed shall be mixed in the proportions of 1:2:4 (cement, sand, 10 mm crushed aggregate) by volume with the minimum quantity of water necessary to give a good hard smooth, steel trowelled finish. The section hereof concerning concrete applies.

Para (403)

The screed is s to be divided into 3 M x 3 M s (approximately 9 sqm. in area) by brass divider strips. Waterproofing of Gate House, Pump House, Staff Accommodations, Compound Wall, etc.

15.2.

Para (404)

The substructure shall be protected by an approved bituminous water proofing membrane. Similar membrane shall be placed on blinding concrete under the concrete floor slabs on grade, if any. The membrane shall be a minimum of 1.5mm thick and be of the self adhesive type. The membranes below floor slab shall be protected from damage during construction activities by a sand-cement screed. The membrane shall be taken up the walls and lapped with DPC to the satisfaction of the Engineer.

15.3. Para (405)

Protection All floor finishes shall be protected from damage by following trades and other causes and any damage, howsoever caused, shall be made good by the Contractor at his own expense to the satisfaction of the Engineer.

15.4.

Defects


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Para (406)

Floor finishes will be rejected if they prove to be defective, due to cracking, crazing, curling, uneven surfaces, or lack of adhesion. Rejected floors shall be replaced at the Contractor's expense to the satisfaction of the Engineer.

15.5.

Terrazzo Floors

Para (407)

Terrazzo floors shall be formed with 300 x 300 x 30 mm hydraulically pressed terrazzo tiles complying with the requirements of BS 4131. The precast terrazzo tiles and skirtings shall be formed with a (1:2 1/2) mix of white or tinted Porland Cement and granular marble chippings for the topping (wearing layer) set on cement and sand backing (1:4) mix and shall be obained from an approved manufacturer.

Para (408)

The tiles shall be cast in heavy steel moulds under pressure. The thickness of topping (wearing layer) shall not be less than 10 mm.

Para (409)

Precast terrazzo skirtings of size 300 x 100 x 30 mm shall be with chamfered top edge and produced in the same proportions and mixes as terrazzo tiles.

Para (410)

Grinding shall be done wet by means of a No. 80 carborundum stone. Filling shall be carried out with a neat cement grout of the same colour as the facing mix and this shall be worked into the surface with a wooden scraper to fill all voids and air holes. Surplus grout shall be removed with a dry cloth. After minimum period of 24 hours, polishing shall be carried out wet by means of a No. 140 carborundum stone.

15.6.

PVC Flooring

Para (411)

PVC flooring shall be flexible 300 mm square minimum 2.5 mm thick PVC tiles complying with the requirements of BS 3261 obtained from an approved manufacturer. PVC vinyl asbestos tiles will not be accepted. The tiles shall be laid by a specialist and the ting layout is to be approved by the Engineer. A matching PVC cove-type skirting is to be used in conjunction with the floor tiles. The tiles and skirting shall be laid on a flat, clean screed, in strict accordance with the manufacturer's instructions.

15.7.

Ceramic Floor Tiles

Para (412)

Vitrified ceramic floor tiles and fittings shall comply with the requirements of BS 6431 and have a maximum water absorption of 0.4%. The sizes and colour of the tiles shall be to the Engineers approval.

Para (413)

The tiles shall be laid on granolithic screed using approved tile adhesive in accordance to the requirements of BS 5385. The ts in the tiles shall be grouted with approved water proof tile grout.

15.8.

Raised flooring

Para (414)

The flooring shall consist of 600 x 600 mm removable floor s ed on a removable stringer floor system. This shall consist of floor s ed continuously on all four edges on easily removable snap-on metal stringers ed on steel adjustable pedestals or s.

Para (415)

The floor finish of the s shall be hard print laminate to a core material of high density processed timber protected against humidity, rotting and fire and shall not be less than 38 mm thick. (not including floor covering), seated in a 0.9 mm galvanised steel tray. The shall be edged with a rigid PVC lipping to all four sides. The lipping shall be planed to finish flush with the surface covering.

Para (416)

The under side, and all four edges of each shall be protected to “class 1” surface spread of flame in accordance with the fire rating requirements of BS476, part 7.


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Para (417)

The floor system shall be suitable for a uniformly distributed floor loading of 24KN/m2 capable of ing a point load of 5KN on a 25mm square anywhere on the surface, with the deflection produced not exceeding 2.00 mm when measured from immediately below the load area or the equipment load whichever is higher.

Para (418)

The assembled floor system shall be reasonably rigid in all direction and be capable of withstanding, without sway or collapse, a seismic force in any horizontal direction of 0.07g.

Para (419)

A separate structure under the equipment to totally relieve the floor s of high point loads to be provided.

Para (420)

All pedestals shall be mechanically fixed(with atleast two screwsdiagonally opposite ) to the sub-floor using an approved fixing device. The sub-floor to be left in a flat, smooth and dust free condition.

15.9.

Alkali/Acid Resistant Floor Tiles

Para (421)

Fully vitrified ceramic floor tiles and fittings shall comply with BS.6431 with a maximum water absorption of 0.3%. Sizes and colour of tiles shall be to the Engineer’s approval.

Para (422)

Colours shall be uniform throughout.

Para (423)

Where required to be non-slip the surface of the tiles shall incorporate a silicon carbide.

Para (424)

Tiles for flooring shall have a matt finish.

Para (425)

The workmanship for tiles shall be similar to ceramic tiles except that the tiles shall be laid on chemical resistant mortar in accordance to ASTM-C-287-71. The pointing of tiles shall be carried out using compatible chemical grouts applied to the recommendation of the approved manufacture.

15.10.

Epoxy Resin Mortar Screed

Para (426)

Solvent free epoxy resin mortar screed shall comprise a 3 component system of epoxy resin, hardner and mineral aggregates. The materials shall be of reputed manufacture such as Feb - Endurafloor EP, Cormix Durafloor EF10, Fosroc Nitofloor TF5000 or equivalent approved.

Para (427)

The screed shall be laid in s above sound concrete substrata which shall be free of defects and loose delaminating material. The surface shall be acid etched to remove surface laitances and provide a rough texture suitable for bonding of the screed.

Para (428)

The acid etched concrete surface shall be washed to remove all acid residue and allowed to dry before application of primer. Screed shall be laid on tacky primer strictly in conformity to the instructions of the approved manufacturer.

Para (429)

The screed shall be laid by an approved applicator and shall be finished to a minimum thickness and sealed.

15.11.

Surface Hardener/Dust Proofer

Para (430)

Materials for treating the concrete surface which will not receive any subsequent finishes shall comprise of a epoxy based sealer and hardner.The materials which the contractor proposes to use shall be subject to Engineers approval and the application shall be strictly in accordance with the manufacturers instructions.

15.12.

Skirtings


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Para (431)

Unless otherwise indicated the skirtings shall be of the same material as the floor finish and to the satisfaction of the Engineer. It shall achieve a satisfactory appearance and provide protection against scuff marks.

16.

CARPENTRY AND ERY

16.1.

Timber

Para (432)

Timber for carpenter's or er's work shall be of approved quality and in general shall be teakwood. All timber shall be subject to inspection by the Engineer, piece by piece, both before and after finishing. The Contractor shall provide all necessary labour and facilities for the inspection of timber.

16.2.

Preservative

Para (433)

Where instructed, timber shall be treated with an approved preservative against rot, termite attack and fire spread. The backs of frames to be fixed to walls and all other bedding surfaces shall be painted 2 coats preservative before painting and fixing. All fixing blocks, pallets and other hidden timber shall be so treated prior to fixing.

16.3.

Workmanship

Para (434)

The quality of workmanship shall be of approved standard. All carpenter's work shall be left "from the saw" unless otherwise described or directed. All er's work shall be wrought and finished with a clean, even smooth surface.

16.4.

Faults

Para (435)

Any Carpenter's or er's work which shrinks, splits, fractures, parts in the ts or shows any other defect shall be removed or replaced to the satisfaction of the Engineer.

16.5.

Builder's Ironmongery

Para (436)

All necessary builder's ironmongery shall be obtained from a single source approved by the Engineer and shall be provided and fixed into position in the best manner by the Contractor. The ironmongery shall be heavy duty types of reputed manufacture such as Modric, Dorma, Union, or equivalent as approved by the Engineer.

Para (437)

Ironmongery for doors, windows shall include but not be limited to hinges, pull handles, push plates, kick plates, knobs, lock and lever sets, door closers, door stops, flush bolts, panic bolts and latches, etc., as appropriate and approved by the Engineer.

Para (438)

The locks shall be linked to DEWA's existing masterkey system and the details of grand and sub masterkey shall be discussed and agreed with the Employer.

Para (439)

The ironmongery items shall be compatible with the composition of doors and windows. The installation for fire rated doors shall also be fire rated.

17.

GLAZING

17.1.

General

Para (440)

The type of materials and nominal thickness of glass shall be as shown on the Drawings or otherwise directed by the Engineer and generally in accordance with B.S. 952. The glass for the doors and window s ading the doors shall be tempered/toughened.

Para (441)

The Contractor shall submit to the Engineer for approval samples of glass and glazing components he proposes to incorporate into the Works.


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Para (442)

The Contractor shall replace all cracked or broken glass and clean all glazing on both sides and all mirrors prior to handing over.

17.2.

Clear Glass

Para (443)

Clear float sheet glass, where required, shall be 6mm thick and of an approved make.

17.3.

Wired Glass

Para (444)

Wired glass shall be either wired cast glass or polished wired glass with 12.5mm square wire mesh 0.5mm in diameter or hexagonal wired cast glass with 23 mm hexagonal wire mesh 0.5mm in diameter.

17.4.

Tinted Glass

Para (445)

Tinted glass shall be body tinted and solar control type. It shall be minimum 6 mm thick and shall have the required colour and thickness generally in conformity with BS 952. The colour of glass shall be uniform throughout and be subject to Engineer's approval. All tinted glass shall be tempered. Each individual glass shall have tempered seal embossed. Glass shall be fixed with UV protected sealant.

18.

PAINTING

18.1.

Paint

Para (446)

Paints for priming, undercoating and finishing shall be ready mixed paints of the best quality for the intended use and comply with relevant standards. All paints shall be obtained from an approved manufacturer who shall certify that the paint is suitable for the intended purpose.

Para (447)

All components of a paint system including different coating material shall be obtained from the manufacturer for the system being used.

Para (448)

The abrasive cleaning material, knotting, fillers, spirits and other ancillary materials shall be as recommended by the paint manufacturer or BS 6150.

Para (449)

The primers and undercoats where applicable, shall also comply with the requirements of the manufacturer of the paint system. All paints shall be obtained from manufacturers to be approved by the Engineer

18.2.

Emulsion Paints

Para (450)

High quality pure acrylic Copolymer based washable emulsion paint containing fungicides to prevent fungus growth for internal or external surfaces used along with compatible primer applied as recommended by the manufacturers from Hempel, Jotun, National Paints or equivalent to the approval of DEWA.

Para (451)

A high quality water resistant paint in black colour shall be applied to all concrete surfaces above suspended ceiling.

18.3.

Oil Paints

Para (452)

Best quality high gloss Alkyd based enamel paint with compactible primer resistant to corrosion, water, fungus, etc., applied strictly in accordance with the manufacturer's recommendations. The paint shall be sourced from Hempel, Jotun, National Paint or other equivalent to the approval of DEWA.

18.4.

Painting of external surfaces


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Para (453)

External textured coating consisting of light textured acrylic Copolymer based emulsion primer coat followed by spray applied acrylic emulsion based texture compound topped with two coats of high quality two component polyurethane isocyanite cured paint giving a high glossy and colour stable surface, carried out strictly as recommended by the paint manufacturers. The system used shall be from Jotun, Hempel, National Paints or any other equivalent to the approval of DEWA.

18.5.

Wood Finishes

Para (454)

These shall be applied according to the finish schedule and be of a type compatible with the required location to BS 6150, Table 6.

18.6.

Bituminous Paints

Para (455)

Where required by the drawings these shall comply with the requirements of BS 1070 or BS 3416 as necessary.

18.7.

Workmanship

18.7.1.

Storage

Para (456)

Materials shall generally be ordered in quantities and containers sized to suit the extent of work and to prevent deterioration of residual quantities in opened containers.

Para (457)

Materials shall be stored to the manufacturers recommendations, but generally in cool, dry conditions protected from direct sunlight.

18.7.2.

Generally

Para (458)

Prepare surfaces and apply contents in accordance with Section 5 of BS 6150 and to the manufacturers instructions. A brief summary of procedures is given hereunder and the BS 6150 clause referred to.

18.7.3.

Ironmongery and Fittings

Para (459)

Remove ironmongery and other removable fittings and replace when decorating is complete.

18.7.4.

Preparation of Surfaces

Para (460)

All surfaces shall be made sound, clean, dry and free from deleterious materials.

18.7.5.

Preparation of Paints

Para (461)

Do not use any decorating materials unless obtained in containers marked with manufacturers name and relevant information such as pot life and mixing instructions. Stir, mix or otherwise prepare as recommended by the manufacturer or directed by the Engineer.

18.7.6.

Conditions of Applications

Para (462)

All coatings may only be applied under conditions of cleanliness, temperature and humidity which meet the manufacturers requirements and to the satisfaction of the Engineer. Application of Paint

18.7.7. Para (463)

The method of applying the coatings shall be approved by the Engineer for each material and nature of the work. All primers to wood and metal shall be brush applied.

Para (464)

When spraying, the Contractor shall ensure that overspray mist, rebound or drift does not cause a nuisance to others or permanent damage to the Works.


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18.7.8.

18.7.8 Re-Priming

Para (465)

Any components that have deteriorated or damaged priming that was applied before delivery to site shall be re-primed to the satisfaction of the Engineer.

18.7.9.

Undercoats

Para (466)

A different shade of undercoat shall be used for each layer.

18.8.

Specific Surface Coatings

18.8.1.

Woodwork

Para (467)

All timber required to be built into, bedded or fixed against brickwork, masonry or concrete shall be given two priming coats and one undercoat on the concealed surfaces.

Para (468)

All woodwork required to be painted shall be knotted, primed, stopped and painted with two undercoats and one finishing coat.

Para (469)

Hardwood which is not required to be painted shall be made perfectly smooth, prepared and oiled twice with linseed oil.

Para (470)

Alternatively, it shall be stained and wax polished, or treated with two coats of an approved varnish.

18.8.2.

Iron and Steel Work

Para (471)

All materials and workmanship shall generally comply with the requirements of BS 5493 for exterior exposed polluted coastal atmosphere.

Para (472)

The whole of the steelwork shall be prepared for galvanising and painting by an approved blast cleaning method using clean abrasive grit. All rust, grease, mill scale and harmful matter shall be removed. The surface shall be blast cleaned to one of the following: • Swedish Standard Sa 2 ½ SIS 05 5900 • U.S. Standard near white finish SSPC-SP-10-63T

Para (473)

The painting system shall comprise of: • • •

2-component inorganic zinc silicate primer 75 micron DFT 2-component polyamide cured epoxy with natural micceous iron oxide 100 micron DFT 2-component polyurethane finishing coat - 40 micron DFT.

Para (474)

On completion of erection works, the damaged areas shall be repaired as specified above and one additional coat of the top coat paint shall be applied.

Para (475)

All primers and paints shall be standard proprietary products manufactured by an approved supplier. The application of paint shall be in complete conformity to manufacturers' recommendations and shall be guaranteed for a typical time to first maintenance of 10 years or more in accordance with BS 5493. Each coat of paint shall be different in colour.

Para (476) Para (477)

Any damaged paintwork shall be cleaned down and re-treated, to the same state as the original before further paint coats are applied.

Para (478)

The Contractor shall submit to the Engineer full details of the protective system to be used for review. All manufacturer's data, instructions and recommendations related to the system shall be submitted for the Engineer's approval.


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Para (479)

Protection for galvanised steel: Epoxy polyamide cured primer (solids by volume 50% to 60%) followed by epoxy polyamide cured high build (solids by volume 50% to 60%) under coat topped with a two component polyurethane isocyanite cured paint with excellent colour and gloss retention properties and resistant to abrasion, impact, chemical attacks, corrosion, etc., applied strictly in accordance with the paint manufacturer's recommendations from Hempels, Jotun, National Paint or other equivalent to the approval of DEWA. The DFT remains same as specified above.

18.8.3.

General

Para (480)

All work shall be properly cleaned and prepared in a way, and using materials, recommended by the manufacturers of the paints concerned. No coat shall be commenced until the Engineer has ed the previous coat as dry, hard and satisfactory. Each coat shall be of a distinct colour from the preceding one and all colours shall be approved by the

Para (481)

Engineer. All paint shall be applied in accordance with the maker's recommendations and shall not contain more than a minimum quantity of thinners or dispersers to permit the satisfactory application of the paint. Spray painting will not be permitted except for internal faces of walls and ceiling. All other paint shall be thoroughly brushed into and completely cover the surface.

19.

DRAINAGE AND DUCTS

19.1.

Codes of Practice

Para (482)

All drainage shall be in accordance with the following Codes of Practice: BS 6367 and BS 8301.

19.2.

Pipes

Para (483)

Drain pipes shall be vitrified clay pipes and fittings of approved manufacture ted with sleeves or sockets, or UPVC pipes complying with BS 4514, 4660 or 5481, equivalent standard as the case may be.

19.3.

Ducts

Para (484)

Cable ducts may be U.P.V.C, concrete, or other material approved by the Engineer and obtained from an approved manufacturer.

19.4.

General

Para (485)

All drains and cable ducts shall be laid in straight lines and regular gradients as described or directed. Great care shall be exercised in setting out and determining the level of the drains. All drains shall be kept clear from earth, debris, superfluous cement and other obstructions during and after laying.

19.5.

Concrete Beds and Casings

Para (486)

Concrete beds and casings to drain pipes and cable ducts under roads shall be of weak concrete and of 150 mm minimum thickness. Elsewhere the pipes and ducts shall be laid on and surrounded with approved granular material.

19.6.

Testing

Para (487)

After completion, drains shall be subjected to an air test or water test, in which a pressure equal to 150 mm of water is to be applied for a period of five minutes without dropping below 125 mm head. Any defects revealed shall be made good at the Contractor's expense. The tests shall be conducted as per BS 5572.


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19.7.

Cable Ducts

Para (488)

After the cable ducts have been completed, a cleaning rod shall be drawn through each duct and a No. 8 gauge galvanised iron fishing-wire drawn in after the rod. The ends of the ducts shall be plugged with a wooden plug and the fishing-wires left in the ducts.

Para (489)

Cable entries into buildings shall be completely sealed around cables to prevent the entry of vermin, water, dust, etc, using suitable cable transit.

19.8.

Manholes

Para (490)

Galvanised malleable cast iron step irons are to be provided and built in as work proceeds.

19.9.

Manhole Covers

Para (491)

Manhole covers shall comply with BS 497 all manhole covers shall be double seal heavy duty.

20.

WALL AND CEILING FINISHES

20.1.

Plaster and Rendering Materials

20.1.1.

Cement

Para (492)

Cement shall comply with the requirements of BS12 or as approved by the Engineer. All cement to be obtained from one source.

20.1.2.

Sand

Para (493)

Sand shall comply with the requirements of BS 1199 or 1200.

20.1.3.

Plaster

Para (494)

Internal plaster shall be retarded semihydrate gypsum-plaster to class B of BS 1191 or anhydrous gypsum-plaster to class C, premixed from approved manufacturers.

Para (495)

Internal plaster in basement, pump house and IBT areas only shall be with cement mortar 1:4 with a water proofing agent added to the mix to the Engineer's approval.

Para (496)

External plaster shall be with cement, mortar 1:4 with a waterproofing agent added to the mix to the Engineer's approval.

20.1.4.

Water

Para (497)

Water shall comply with the requirements of sub-section Concrete.

20.1.5. Para (498)

Lathing Expanded metal lathing shall comply to the requirements of BS1369 or BS405.

20.1.6.

Bonding Agents

Para (499)

Polyvinyl acetate emulsion type bonding agents shall comply with BS 5270.

20.2.

Workmanship

20.2.1.

General


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Para (500)

Plastering shall be carried out to the requirements of BS 5492 and rendering to BS 5262.

20.2.2.

Storage

Para (501)

Cement and plaster shall all be delivered to site in the manufacturer's sealed bags or containers. They shall be stored in a dry, weatherproof area clear of the ground.

20.2.3.

Mixing

Para (502)

The plaster mix proportions shall be those as directed by the Engineer, selected from trial mixes and s to be carried out by the Contractor.

Para (503)

All mixing shall be carried out in a clean mechanical mixer or other approved vessel.

Para (504)

All undercoats shall be scored to provide a key for the finish coats.

20.2.4.

Lathing

Para (505)

Metal lathing shall be fixed with galvanised nails or staples or to the manufacturer's instructions and to the satisfaction of the Engineer.

20.2.5.

Bonding Agents

Para (506)

Where required or as directed by the Engineer, these shall be applied in strict accordance with the manufacturer's recommendations.

20.2.6.

Preparation of Backgrounds

Para (507)

Backgrounds for plasterwork shall be prepared by carefully brushing to remove dust and other adherent particles of any other material likely to impair the bond of the undercoat with the structure. If undue suction occurs on the background surface, this shall be sprinkled with water to prevent drying the applied plaster.

Para (508)

ts of blockwork which is to be plastered or rendered shall be raked out to a depth of 13 mm.

20.2.7.

Interaction of Materials

Para (509)

In no circumstances shall cement be used in the same mix as gypsum plaster, nor shall the two materials be allowed to contaminate each other. Any materials inadvertently contaminated shall be rejected from the site.

20.2.8.

Inspection

Para (510)

Any and all defects shall be made good to the satisfaction of the Engineer.

Para (511)

Upon completion of plastering and rendering works the Contractor shall clear away and clean up any splashes, drippings etc.

20.2.9.

Curing

Para (512)

Cement and plaster shall be kept moist by sprinkling with water at regular intervals for a period of at least three days and until no powdery particles are present, to the satisfaction of the Engineer. Gypsum plasters do not require curing. All external rendering shall be protected from rain and direct sun for a period of 7 days.

20.2.10.

Cement Wash


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Para (513)

The cement wash to fairfaced blockwork shall be well rubbed or bagged into the surface of the blocks in order to produce an overall smooth surface.

20.2.11.

Workmanship Generally

Para (514)

All proprietary brands of plaster or plastering materials in this specification shall be selected and applied strictly in accordance with the manufacturer's instructions regarding the different purposes and backgrounds for which they are intended. Particular attention shall be paid to the manufacturers instructions regarding the time allowed to elapse between mixing and using.

Para (515)

The plastering shall be carried out by men experienced in this type of work and the whole of the work shall be finished to a true and even surface, free from all defects. Any cracks or other defects shall be cut out and made good.

20.3.

Wall Tiles

20.3.1.

Materials

Para (516)

Wall tiles shall be fully vitrified ceramic tiles and fittings complying with the requirements of BS 6431 and having a maximum water absorption of 0.4%. The sizes and colour of the tiles shall be to the Engineer's approval.

Para (517)

The tiles shall be true to shape, flat and free from flaws, cracks and crazing.

Para (518)

The tiles and the fittings shall be obtained from the same manufacturer.

20.3.2.

Workmanship

Para (519)

The floated coat shall consist of 13 mm thick waterproof plaster; it shall be finished with a woodfloat. The Contractor shall ensure that the floated coat is plumb and free from all unevenness. Sufficient time for complete drying shrinkage shall be allowed to elapse between the completion of the floated coat and the start of tiling.

Para (520)

The work shall be properly set out to the Engineer's satisfaction. The height of tile courses shall be set out properly by means of a tiling rod; all tiles and ts shall be accurately aligned, both vertically and horizontally. ts between the tiles shall be 2mm wide or as recommended by the tile manufacturer. Continuous expansion ts shall be made at all internal wall angles.

Para (521)

All tiles shall be dipped in water to ensure that they are completely clean prior to the application of the ceramic tile fix. All tiles shall be immersed in water in clean containers for at least half an hour before use. Tiles shall then be stacked lightly together on a clean surface to drain with the end tiles turned glaze outwards. They shall be fixed as soon as all surface water has gone - they must not be allowed to dry out more than this.

Para (522)

The rendered backing for tiling shall be clean and will be wetted (just enough to prevent it from absorbing water from the fixing bed) immediately prior to tiling. The tiling shall be bedded in Ceramic Tile fix or similar tile adhesive which shall be trowelled on to the wall with a plasterer's trowel having 6mm x 6 mm notches at 25 mm centres; the tiles shall be tapped or pressed into position to a true plane.

Para (523)

Approximately two days after the fixing of the tiles, all ts shall be pointed with approved tile grout; the finish shall be flush and free from all voids and irregularities.

Para (524)

All wall faces shall be finished plumb and flush throughout, free from unevenness and irregularities of plane; all angles shall be straight and true. The finished work shall be left clean and free from all materials; cleaning down must not be carried out with materials which will scratch or in any way impair the finished work. Final polishing shall be done


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with a dry cloth. The Contractor shall be responsible for the adequate protection of the tiling from all damage until the handing over. Any damage which does occur shall be made good by the Contractor at his own expense. The whole of the work shall be left in a state satisfactory to the Engineer. 20.3.3.

Acid Resistant Tiles

Para (525)

The workmanship for tiles shall be similar to the ceramic wall and floor tiles except that the tiles shall be laid on chemical resistant mortar which shall comprised of sulphur mortar in accordance to ASTM-C 287-71. The pointing of tiles shall be carried out using compatible chemical grouts applied to the recommendations of the approved manufacturer.

20.4.

Plasterwork

Para (526)

Undercoats for external plaster shall consist of Portland Cement, and sand gauged in the proportions 1:3. The undercoat shall be keyed to take the finishing coat and allowed to dry out completely before the latter is applied. The total thickness of two coats shall not be less than 15 mm.

Para (527)

Internal surfaces shall be plastered to a minimum thickness of 15 mm. work shall be carried out as per recommendations of the manufacturer.

20.5.

Suspended Ceilings

Para (528)

Horizontal suspended ceilings where provided shall generally be of mineral fibre type of approved manufacture. 600 x 600 mm square modular s made of incombustible material and fixed in an exposed T grid. The boards shall be of self-finished type. The ceilings shall be accurately aligned to levels. The suspension shall not be ed on any other fixture commonly ing other services such as air

Para (529)

conditioning ducts, cable trays etc. and adequate clearance shall be maintained for installation of light fittings.

Para (530)

The s shall be secured with locking clips to the grid. The visible face of the s shall have a self-finished surface.

Para (531)

The exposed T grid shall be aluminium adequately ed from the RC roof slab above, on adjustable straps and hangers as required.

Para (532)

At perimeter walls and columns the grid shall be neatly trimmed with angle trimmers.

Para (533)

If required, for air-conditioning purposes, slots or grilles will be incorporated in the ceiling grid system. These shall be neatly formed and edged in material matching the grid.

Para (534)

In other areas where required and shown on the drawings, the ceiling shall be made airtight at individual s and at junction of ceilings and walls.

Para (535)

Other equal and approved insulating material and methods of fixings may be used subject to the Engineer's prior approval. The Tenderer shall specify the type and manufacture of his proposals for the above ceilings, in the Schedule included in the document.

Para (536)

Para (537)

Samples of materials shall be submitted to the Engineer for approval before ordering.

Para (538)

high quality water resistant paint in black colour similar to Hempanol from Hempel or equivalent shall be applied to all concrete surfaces above suspended ceiling.

20.6.

Finishes Generally


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Para (539)

All finishes are to be of high quality and all proprietary finishes and treatments are to be to the approval of the Engineer and applied accordance with the manufacturers instructions.

Para (540)

The following table lists the required building finishes to the various areas:-


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Civil Works

ROOM MAIN SUB/STN BUILDINGS: Entrance, hall & corridor

Terrazzo tiles

Toilet

Non-slip ceramic tiles

Battery/Charger

Non-slip ceramic tiles laid to falls

Workshop stores & records

Hardened solvent free epoxy resin mortar screed minimum 4 mm thick, sealed. * Hardened solvent free epoxy resin mortar screed minimum 4 mm thick, sealed. * High quality PVC tiles.300 x 300 x 2.5mm.

Capacitor Bank rooms

Telecom Room

FLOOR

FINISHING SCHEDULE SKIRTING 100 mm high terrazzo to match floor with quadrant coving. ------

100 mm high Ceramic to match floor with quadrant coving 100 mm high epoxy screed skirting. 100 mm high epoxy screed skirting. PVC 100 mm high to match floor

Control Room

* High quality PVC tiles.300 x 300 x 2.5mm.

PVC 100 mm high to match floor

Relay Room

*High quality PVC tiles. 300 x 300 x 2.5 mm.

PVC 100 mm high to match floor

LVAC

*Hardened solvent free epoxy resin mortar screed minimum 4 mm thick sealed.

100 mm high epoxy screed skirting

11/22kV Switchgear Hall

Hardened solvent free epoxy resin mortar minimum 6 mm thick, sealed.

Epoxy screed skirting 100 mm high.


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WALLS

CEILING

Plastered sealed, & painted with washable emulsion paint. Colour to the approval of DEWA. Plastered and finished with glazed ceramic tiles to top of door height. Seal, undercoat & washable emulsion paint above. Plastered, sealed and painted with washable emulsion paint. Colour to the approval of DEWA. Plastered, sealed & painted with washable emulsion paint. Colour to the approval of DEWA. Plastered sealed, & painted with washable emulsion paint. Colour to the approval of DEWA. Plastered sealed, & painted with washable emulsion paint. Colour to the approval of DEWA. Plastered sealed, & painted with washable emulsion paint. Colour to the approval of DEWA.

Suspended ceiling.

Plastered sealed, & painted with washable emulsion paint. Colour to the approval of DEWA. Plastered sealed, & painted with washable emulsion paint. Colour to the approval of DEWA.

Suspended ceiling.

Plastered, sealed & painted with washable emulsion paint. Colour to the approval of DEWA

Fair faced concrete, prepared, sealed and painted in textured finish to approval. Airconditioning ducts to be covered

Suspended ceiling with 60 x 60 cm aluminium tiles compatible with lighting. Fair faced concrete, prepared, sealed and painted in textured finish to approval. Suspended ceiling.

Fair faced concrete, prepared, sealed and painted in textured finish to approval. Suspended ceiling.

Suspended ceiling.

Suspended ceiling


1.5.3.1.0.01-Rev.10

Civil Works

FLOOR

FINISHING SCHEDULE SKIRTING

132kV GIS Hall

80mm screed laid to level finished with epoxy paint.

Epoxy paint skirting 100mm high

Basement

Screed laid to falls, finished with epoxy paint.

Epoxy paint skirting 100 mm high.

Transformer enclosures

Epoxy painted concrete.

PUMP HOUSE

Hardened solvent free epoxy resin mortar screed minimum 4 mm thick, sealed.

Epoxy screed skirting 100 mm high.

GATE HOUSE: Guard Room

Terrazzo tiles.

100 mm high terrazzo to match floor with quadrant coving.

Plastered, sealed & painted with washable emulsion paint. Colour to the approval of DEWA

Toilet

Non-slip ceramic tiles.

-----

Plastered with glazed ceramic tiles to top of door height. Sealed & painted with washable emulsion above. Colour to the approval of DEWA.

WATCHMAN ACCOMMODATION: Bedrooms and Lobby

Terrazzo tiles

100 mm high terrazzo to match with quadrant coring.

Plastered sealed & painted with washable emulsion paint. Colour to the approval of DEWA.

Kitchen

Non-slip ceramic tiles

----

Plastered with glazed ceramic tiles to top of door, sealed & painted with washable emulsion paint above. Colour to the approval of DEWA.

ROOM


fairfaced

-----

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WALLS

Plastered, sealed and painted with washable emulsion paint. Colour to the approval of DEWA. Plastered (with sand cement mortor ) sealed & painted with washable emulsion paint. Colour to the approval of DEWA Concrete walls plastered sealed & painted as per clause 18.4. Colour to the approval of DEWA. Plastered, sealed & painted with washable emulsion paint. Colour to the approval of DEWA

CEILING by aluminium lined gypsum board bulk heads. Fair faced concrete, prepared, sealed and painted in textured finish to approval. Fair-faced concrete sealed & painted with washable emulsion. Colour to the approval of DEWA. Colour coated aluminium cladding, as per Clause 5 Fair faced concrete, prepared, sealed and painted in textured finish to approval. Plastered (with sand cement mortar) sealed and painted with washable emulsion paint. Colour to the approval of DEWA. Suspended ceiling, with 60 x 60 cm. aluminium tiles compatible with lighting.

Plastered (with sand sealed and painted emulsion paint. approval of DEWA. Plastered (with sand sealed and painted emulsion paint. approval of DEWA.

cement mortar) with washable Colour to the cement mortar) with washable Colour to the


1.5.3.1.0.01-Rev.10

Civil Works

ROOM

FLOOR Non-slip ceramic tiles

Bath

FINISHING SCHEDULE SKIRTING -----

Para (541)

* Suitable raised floor to be provided where there is no cable basement.

Para (542)

Note : • •

WALLS Plastered with glazed ceramic tiles to top of door. Sealed & painted with washable emulsion above.

CEILING Plastered (with sand cement mortar) sealed and painted with washable emulsion paint. Colour to the approval of DEWA.

A high quality water resistant paint in black colour shall be applied to all concrete surfaces above suspended ceiling. Floor along all fire escape routes shall be marked with reflective paint as per relevant standard and to DEWA’s approval


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Civil Works

21.

PLUMBING

21.1.

Extent of Work and General

Para (543)

This section describes the services to be provided in general and addresses the general requirements in respect of sanitary plumbing, drainage, rainwater and domestic water services.

Para (544)

All aspects of plumbing work shall comply with government/local authority regulations and codes of practice and work shall be subject to their approval at various stages as required by law. The Contractor shall be responsible for ensuring that all aspects of materials, workmanship and testing have appropriate government approval.

Para (545)

All domestic water services pipework shall be sized to provide the necessary flow rates to sanitary fittings on the basis of probable simultaneous demands. The method of calculating the size of pipework shall be in accordance with the British Standards Code of Practice .310 using demand units to assess the probable simultaneous demand for water at any point in the system. Velocity of water in the system shall be limited to 1.5 metres per second as a maximum and the demand units and flow rates for sanitary fittings are in accordance with the following table: Fitting

Demand Units

Flow Rate

Basin

1.5 W.C. Cistern

0.15 2

Litres/Sec 0.12

Para (546)

All sanitary plumbing and drainage installations shall comply with BS.8301 and the regulations and by-laws of the Local Authorities. The Contractor shall arrange for a permanent water supply facility from the local authority network. The charge for permanent water connection (payable to DEWA) will be borne by DEWA.

Para (547)

Foul water drains shall be installed in accordance with BS.8301.

Para (548)

Easy bends of either long radius type or two 135 deg. bends shall be used at the base of all plumbing stacks. Access points shall be provided on all draining runs by manholes of an appropriate size.

Para (549)

All drains shall be accurately laid, true to line and gradient from point to point. Manholes shall be provided at changes of direction or gradient and at points of connection. Drain pipe runs between manholes shall be absolutely straight. Lines and falls shall be accurately set out.

Para (550)

The Contractor shall provide all materials, labour, equipment, plant and incidentals to execute, complete and maintain the works. The Contractor shall carry out the tests required under supervision and shall make good and replace any defective work. The Contractor shall be responsible for protection of all plumbing from any damage whether due to the concurrent work of the other trades or otherwise and he shall clean up upon completion leaving all works in perfect working order and to the satisfaction of the Engineer.

Para (551)

The entire works shall be robust and designed for a long service life with minimum maintenance. Special care shall be taken in deg drainage works to ensure the least chance of blockage.

21.2.

Pipes and Fitting Materials - Internal

21.2.1.

Cold Water Services

Para (552)

Unplasticised PVC (UPVC) pipes for cold water services shall comply with BS 3505 Class E for underground piping. Others shall comply as per Clause 11.21.2.2 below.


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21.2.2.

Not Used

21.2.3.

Sanitary Plumbing and Drainage

Para (553)

uPVC soil and waste water pipes and fittings shall comply with BS 4514 and be protected against misuse or attack by vermin. Fittings shall be of the push-fit or solvent welded type.

21.2.4.

Rainwater Systems

Para (554)

Concealed or encased rainwater pipework as well as exposed ones shall be uPVC to BS 4576 and BS:4514.

Para (555)

All pipes and fittings shall be obtained from an approved manufacturer.

21.3.

Pipes and Fitting Materials - External

21.3.1.

Hot and Cold Water Services

Para (556)

Solid drawn copper tubes shall comply with BS 2871, Part 1, Table 'x' capillary or compression fittings complying with BS 864. Exposed hot and cold water pipe shall be pre insulated type.

Para (557)

Galvanized seamless steel tubes shall comply with BS 1387 (Heavy tubes) with galvanized malleable cast iron fittings to BS 143.

21.3.2.

Underground Drainage

Para (558)

Underground foul, waste and surface water drainage shall be uPVC to BS 4660 with pushfit ts and fittings.

Para (559)

Underground chemical and oily water drains shall be vitrified clay to BS 65 and BS 540 or equivalent to be approved by DEWA's Engineer.

21.4.

Pipework and Accessories

21.4.1.

Installations

Para (560)

All piping shall generally be fixed in strict accordance with manufacturer's instructions or BS Codes of Practice using the correct brackets and clips as appropriate at the recommended centres.

21.4.2.

Traps

Para (561)

All traps shall generally be of the bottle trap type with 75 mm seal unless specified otherwise.

21.4.3.

Not Used

21.4.4.

Taps and Fittings

Para (562)

Taps and all visible metal fittings shall be heavy duty chromium plated. Drinking water outlets shall be clearly labelled, and hot and cold taps labelled or colour coded.

Para (563)

Provision shall be made for isolating individual appliances by the installation of stop-cocks in the water supply pipes.

Para (564)

Drain-cocks shall be installed to allow complete draining of the whole system.

21.4.5.

Insulators


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Para (565)

ts between different metallic materials shall be made with suitable insulators to prevent electrolytic action.

21.4.6.

Valves and Cocks

Para (566)

All valves and cocks shall be located in an accessible position for operational and maintenance purposes.

Para (567)

Valves and cocks for use on hot and cold water services shall comply with the regulations and requirements of the appropriate Water Authority concerned and arrangements shall be made with that Authority and no extras shall be allowed for any charges for testing and stamping of valves and cocks which may be required.

Para (568)

Valves up to and including 50 mm bore shall, unless otherwise specified, be screwed in accordance with BS 21 : 1973 "Pipe threads for tubes and fittings where pressure tight ts are made on the threads" and subsequent amendments.

Para (569)

On open circuit high pressure systems such as domestic water and irrigation water services, all isolating valves shall generally be stopcocks.

21.5.

Rainwater Pipes and Accessories

Para (570)

Rainwater pipes and fittings shall be constructed of the following materials:

Para (571)

Rainwater pipes encased in concrete and exposed ones shall be - uPVC to BS 4576 and BS: 4514.

Para (572)

Alternative materials may be used subject to the prior approval of the Engineer.

Para (573)

Bends, swan necks, outlets and other fittings shall as far as possible be of materials matching the main pipe. Where dissimilar materials are formed together, approved adaptors and methods shall be used.

Para (574)

ting shall be in accordance with Codes of Practice relevant to the materials concerned.

Para (575)

Metal surfaces in with asphalt shall be scored, wire brushed, and treated with suitable bitumen based primer, before installation. Where the rainwater pipes discharge above ground, they shall be fitted with a 45 degree elbow directing rainwater away from the building.

21.6.

Sanitary Fittings, Materials and Equipment

21.6.1.

General

Para (576)

All sanitary fittings shall be Ideal Standard, Twyfords, Armitage Shanks or equivalent make. Sanitary fittings and their connections, services, wastes, etc. shall be located, designed and installed to the satisfaction of the Engineer.

21.6.2.

Quality and Colour

Para (577)

Unless otherwise approved by the Engineer, the quality and sizes of the fittings shall be according to British Standards and as listed below. Unless specifically shown on the drawings, the sanitary appliances shall be in white.

21.6.3.

Wash Basins

Para (578)

Wash basins shall be enamelled glazed fireclay complying with BS 1188 size 55 x 40 cm weighing approximately 20 kg fitted with 13 mm diameter chromium plated pillar taps, combined overflow and 32 mm diameter trapped waste with plug.


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21.6.4.

Water Closets (Asiatic)

Para (579)

Asiatic Water Closets Suites shall be sea water resistant and shall comprise glazed fireclay squatting slab, pan, `S' or `P' trap with 90 mm bore outlet, two gallon capacity high or low level enamelled cast iron or glazed fireclay or plastic flushing cistern fixed to walls with concealed fixing, 32 mm (high level) or 38 mm (low level) diameter flush pipes, noncorroding valveless siphon, 13 mm low pressure ball valve and union, 19 mm overflow and union, and either flushing handle or pull and chain. In a position adjacent to each Asiatic Water Closet, a suitable water draw off point shall be provided together with a 12 mm bibtap. A flush valve may be installed instead of the flushing arrangement described above, if required.

21.6.5.

Water Closets (European)

Para (580)

European Water Closet Suites shall comprise glazed fireclay pan complying with BS 1312, weighing approximately 20 kg and having `S' or `P' trap with 90 mm bore outlet, two gallon capacity high or low level enamelled cast iron or glazed fireclay flushing cistern fixed to walls with concealed fixings, 32 mm (high level) or 38 mm (low level) diameter flush pipe, non-corroding valveless siphon, 13 mm low pressure ball valve and union, 19 mm overflow and union, either flushing handle or pull and chain, and with double flap solid section plastic ring seat complying with BS 1254.

21.6.6.

Flushing Cisterns

Para (581)

Flushing cisterns and flush pipes shall comply with BS 1125.

Para (582)

Ball valves shall comply with BS 1212 and marked with the manufacturer's name or trade mark. Floats shall comply with BS 2456 and shall be marked with the manufacturer's name or trade mark. A manufacturer's certificate testifying that the flushing cisterns comply with BS 1125 shall be submitted to the Engineer.

21.6.7.

Urinals

Para (583)

Bowl urinals shall be vitreous china bowl urinal, overall size approximately 41 cm by 61 cm complete with 1 1/4 inch chromium plated outlet and all necessary concealed hangers and s. The urinals shall be fixed in single or in ranges of two, three, four or more urinals and as shown on the drawings with vitreous china divisions of 67 cm/150 cm height approximately. Flushing cisterns shall be enamelled fireclay automatic flushing cistern with copper syphon and 1/2 inch inch drip tap with loose key. The cistern shall be of a capacity of nine litres for each single urinal or for a range of two urinals, fifteen litres capacity for a range of three urinals served, and complete with pair cast iron cantilever brackets for each, built in to wall. The flush pipes, reduced size sparge pipes, pipe fittings and spreaders (of suitable diameters as recommended by the manufacturer) between cistern and bowls shall be chromium plated with necessary 1 1/4 inch traps (one for each bowl) and all necessary chromium plated connection to supply and waste water piping.

21.6.8.

Taps and Fittings

Para (584)

Taps and all visible metal fittings shall be Euro Standard, Grohe, Hansa or equivalent make, heavy duty quality complying with BS 1010. They shall be marked with the manufacturer's name or trade mark and nominal size.

21.6.9.

Sundry Fittings

Para (585)

Other sundry fittings shall be of approved quality and manufacture and shall include such fittings as chromium plated paper holder wall mounted adjacent to the closets, chromium plated towel rails with end brackets adjacent to sinks and wash basins, wall mounted mirrors over wash basins.


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21.6.10.

Floor Drains

Para (586)

Floor drains shall be of the best quality and to the approval of the Engineer. Each floor drain shall have an integral or separated P-trap and the necessary raising pieces with the necessary side inlet opening (or openings), covers to be of chromium plated cast brass.

21.6.11.

Waste Water Gully Traps

Para (587)

Unless otherwise directed, waste water gully traps or P-traps shall be of UPVC as per relevant British Standard.

Para (588)

Each gully trap shall be equipped with a conical gully inlet and a raising piece with the necessary side inlets. The gully inlet and the raising piece shall be of the same material as the gully.

Para (589)

The gully trap together with the gully inlet and the raising piece shall be fixed and surrounded with not less than 10cm thick plain concrete from bottom and sides of the same and as directed by the Engineer.

Para (590)

In areas subject to use of excessive water, the floor drains shall be in the form of channels of adequate size fitted with removable grilled covers suitable for heavy traffic and connected to separate drainage system. Detailed design and information shall be submitted to the Engineer to obtain his approval on the system and materials prior to commencement of the work.

21.6.12.

Water Storage Heaters

Para (591)

Water storage heaters shall be of the pressure type suitable for unvented systems.

Para (592)

The water shell shall be constructed from high carbon steel with a lining of glass or equal approved proprietary non-corrosive and non-toxic material.

Para (593)

The shell shall be equipped with a replaceable magnesium anode and shall be tested to non less than 2,000 kPa (20 Bar).

Para (594)

The outer jacket shall be mild steel with a baked enamel finish, and shall have removable access covers for maintenance purposes.

Para (595)

The insulation shall be high density fibreglass matting of at least 25 mm thickness or injected polyurethane foam.

Para (596)

Heating elements shall be screw-in type incaloy sheathed suitable for 220 volts supply with an integral thermostatic control adjustable through the range of 49oC to 82oC with a high temperature cut out.

Para (597)

A factory fitted combination valve assembly on the water inlet shall incorporate an isolating valve, a non-return valve, and a thermal and pressure relief valve set at 99oC and 700 kPa (7.0 Bar) which shall be piped to safe discharge.

Para (598)

The type, storage capacity and element rating of the heaters shall be as described in the schedule.

Para (599)

Immersion electric heaters shall further comply with BS 3456, Section 2.21. Thermostats shall comply with BS 3955, Section 2B. Notwithstanding the stipulations of these standard specifications, thermal storage electric water heaters and their installation shall be in accordance with the prevailing government regulations.

Para (600)

The contractor must obtain the Engineer's approval on the capacity, number, type and manufacaturer of the water heaters prior to ordering them.


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21.6.13.

Water Storage Tanks

Para (601)

One-piece cylindrical storage tanks shall be manufactured from glass fibre reinforced thermosetting epoxy resin in thicknesses of not less than 8 mm with an integral opaque membrane for the prevention of ultra-violet penetration.

Para (602)

Horizontal tanks shall feature integral hollow s suitable for stabilizing in-situ with a concrete infill.

Para (603)

Ends shall be dished and construction generally shall be within the requirements of BS 4994 : 1987.

Para (604)

Tanks shall have the following accessories: • • • • • • • •

Valved inlet to ball float valve Valved outlet Drain with Hose Union Overflow with insect screen Vent pipe with insect screen Hinged access cover with stainless steel hinges and securing clamps Float control switches as scheduled. Unions shall be provided to all valves fitted to the tank for easy disconnection.

21.6.14.

Transfer Pump Sets

Para (605)

Transfer Pump sets for domestic services shall be of multi-pump format.One running and one standing by with auto start facility in case of running pump failure and cyclic change over.

Para (606)

Constant speed variable volume constant pressure pump sets shall comprise high efficiency multistage pumps arranged for parallel/cascade operations, complete with and hydraulic accumulator diaphragm vessel.

Para (607)

Motors shall be totally enclosed fan ventilated, with Class "F" insulation, operating at a speed not exceeding 2900 rev/min. wound for a 380V, 3-phase, 50 Hz. electrical supply.

Para (608)

Diaphragm vessels shall be of pressed steel welded shell construction with non-toxic internal coating and renewable flexible impermeable diaphragm membrane. A schrader valve shall be provided for precharge pressure adjustment, and the vessels shall be installed with isolating valves and drain cocks for ease of maintenance.

Para (609)

Suction and discharge manifolds shall be constructed in the materials specified for the relevant water service, and shall be complete with bronze isolating valves and non-return valves to the standards described elsewhere in this specification.

Para (610)

Control s shall comply fully with electrical sections of this specification and shall meet with the requirements of the IEE Wiring Regualtions.

Para (611)

Enclosures shall be heavy gauge steel, stove enamelled, dust and damp protected to IP55 and shall incorporate the following components: • • • • • •

Door interlocked mains isolator Individual motor starters with thermal overload relays incorporating single phasing protection (direct on line up to 5.5 kW, Star-Delta 7.5kW and above). Individual pump and control fuses (HBC to BS.88) in fully shrouded fuse holders. Hand-off auto switches for each pump. Duty pump/lead pump selector switches. Indicator lamps for mains on, pump run and pump trip for each pump.


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•

Anti-condensation heater.

Para (612)

The control circuitry shall provide for the connnection of float switch controls for the protection of the pump set against dry running.

Para (613)

All components shall be pre-wired factory assembled on a common baseplate constructed from heavy gauge zinc plated steel or painted heavy gauge rolled steel section.

Para (614)

All pump sets shall have flexible connections on the suction and discharge connections.

21.7.

Builders Work

Para (615)

Where pipes are fixed on the surface of the walls, the Contractor shall perform all cutting and pinning for holderbats or plugging or screwing for pipe clips. Where pipes are concealed in walls etc., the Contractor shall peform all cutting and subsequent making good. Pipes through walls or floors shall through metal sleeves and covers at points of emergence shall be provided. All builder's work by the plumber shall be finished in a neat and workmanlike manner and to the satisfaction of the Engineer.

21.8.

Testing

Para (616)

When the installation has been completed to the satisfaction of the Engineer, it shall be tested for water tightness and leakage. Rate of flow and correct operation shall also be checked.

Para (617)

The Contractor shall provide all facilities for the testing and making good of any defects to the satisfaction of the Engineer.

21.9.

Cleaning

Para (618)

The Contractor shall carefully clean out all cold water and hot water tanks. Service pipes, sanitary fittings throughout, traps and wastes. The Contractor shall also overhaul and make good all flushing valves, check regulating valves, check taps including rewashering as necessary and leave all works in perfect clean working condition.

21.10.

Disinfection

Para (619)

After completion of all tests, the replacement and repairs, all water supply systems shall be thoroughly flushed with water to remove sediment. Disinfectant shall be applied to all piping systems of potable cold and hot water supplied.

Para (620)

The disinfectant shall be chlorine, in the form of a hypochlorite solution. During chlorination, all valves and equipment shall be operated, to ensure that chlorine reaches all parts of the system. Water and chlorination agent shall be fed into the system at rates that will provide a residual chlorine content of not less than 10ppm after a retention period of 24 hours. (An initial application of 30 ppm will generally be required).

22.

BOUNDARY WALL FENCE AND GATES

22.1.

Boundary Wall

Para (621)

The boundary walls shall be of blockwork or concrete construction 2.4m high designed to resist a wind speed of 160km/hr. The walls shall be plastered and painted with a textured polyurethane paint system as specified for the substation building.

Para (622)

Pointed steel spikes - galvanised and painted as per specification for steel work shall be fixed above the wall.

22.2.

Fence


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Para (623)

Fence shall be chain link type designed to resist wind load at 160 km per hour.

Para (624)

The fence shall comprise of 50 x 50 chain link mesh, galvanised wire not less than 2.65 mm core diameter and with PVC coating not less than 3.75 mm diameter. It shall be at least 2.4 m above ground and buried at least 0.3 m below ground level. The tension lines shall be not less than 4 lines of 3.5 mm core diameter and PVC coating not less than 4.1 m diameter.

Para (625)

The ing posts shall be hot dip galvanised to BS 729 after fabrication and polyester powder coated to a minimum thickness of 80 micron. The posts shall have extension arms beyond chain link mesh to accommodate 3 lines of barbed wire. The posts shall be at least 60 mm diameter 2.9 mm thick for intermediates and 76 mm diameter and 4.5 mm thick for end straining posts.

Para (626)

The barbed wire shall have a core diameter of 1.6 mm and the diameter with PVC coating shall be a minimum of 1.95 mm.

Para (627)

The material shall be installed generally as per the requirements of BS 1722.

22.3.

Gate

Para (628)

The gate for substation shall be of structural steel construction using rolled hollow steel sections of grade 43C generally in conformity with BS 4848. The gates shall be to the height of compound wall generally in conformity to BS 1722 part 10.

Para (629)

The gate for the Substation shall have steel spikes and shall be galvanised and painted as the structural steel items.

22.4.

Line Termination and Sealing End Compounds

Para (630)

Reinforced concrete foundations, including all eye bolts and fixing bolts, shall be provided for all Sealing End Structures, Anchor Blocks Surge Arrester Structures, etc., as required.

Para (631)

The foundations whether piled or not must be properly designed in reinforced concrete, and capable of resisting all design loads of down droppers, plant and structures.

Para (632)

Interlocking blocks, minimum 80 mm thick on compacted subgrade appropriate to the ground conditions, shall be provided over all of the compounds in an approved colour.

Para (633)

The compound surfacing shall be laid to falls leading to stormwater soakaways.

Para (634)

A 2.4 M boundary wall capable of withstanding vehicle impact on a suitable foundation shall be provided around all compounds. The walls shall be rendered and painted on both sides, and capped with a precast concrete coping. Pointed steel spikes - galvanised and painted as per specifications for steel work shall be fixed above the wall.

Para (635)

Gates of RHS steel construction complete with all fittings shall be provided where indicated on the drawings.

23.

LIGHTING AND SMALL POWER

23.1.

Scope

Para (636)

This section of the Specification includes for the interior and exterior lighting and small power systems.

Para (637)

Whenever practicable fixtures shall be sourced locally.


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Para (638)

All civil works associated with this section of the works shall be deemed to be included either as part of the main civil engineering works or as part of the works in this section. No additional payments will be made for such requirements.

Para (639)

The requirements of this section of the works are subject to the Main Conditions and Specifications laid down in other sections of the Tender Document.

23.2.

General Standards

Para (640)

The completed installations shall comply in all relevant respects with Dubai Electricity & Water Authority Wiring Regulations for Electrical Installation and approved Code of Practice in Dubai and also with the Codes of Practice issued by the Chartered Institution of Building Services, with BS7671 (Formerly IEE Wiring Regulations), or with such other local regulation that may be in force at the site.

Para (641)

The lighting and small power equipment and installation shall comply with other sections of this Specification as appropriate.

Para (642)

All lamps, fittings, plugs, sockets and general accessories of the same size and types shall be similar and interchangeable throughout the installation.

23.3.

Defects Liability Period

Para (643)

The Contractor shall be responsible for the efficient and good working of the installations comprising this section of the Specification for the agreed period as set out in the Specification document.

23.4.

Approvals

Para (644)

The Contractor shall submit to the Engineer for approval copies of all his calculations forming the basis for the designs of the specified systems which shall be shown on the working drawings also to be submitted for approval.

Para (645)

Any approvals shall not, however, relieve the Contractor of his contractual responsibilities which include obtaining DEWA/local authority approvals for electrical wiring installations.

23.5.

Lighting Requirements

Para (646)

The lighting installations shall be designed to give the standard service illuminations set out in Clause 23.29 Table II and shall incorporate emergency lighting where indicated. Control rooms, relay rooms, telecommunications equipment rooms, offices and stores shall have the service illumination measured at 850 mm above finished floor level. All other areas shall have the service illumination measured at floor level. Infrared movement sensors to be provided in all areas to control automatic switching on and off of at least 50% lights in a room.

Para (647)

The installations shall also meet the limiting glare index requirements as set out in the specified codes of practice. This schedule gives proposals for the types of lighting fittings to be used in the area, type of control to be employed, number of socket outlets and the types of mounting expected to be suitable for the respective areas. Where discharge and fluorescent light sources are to be used in areas containing rotating or reciprocating machinery, the fittings shall be allocated between the 3 phase and neutral in such a manner as to avoid stroboscopic effects. When 3 phase lighting installations are to be used or switching controlled by pushbuttons located in the area to be illuminated are preferred.

Para (648)

In all rooms and corridors having two entrances the lighting installation shall have two way switching, the switches being located in appropriate positions adjacent to the entrances.


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Para (649)

Emergency lighting shall be arranged to illuminate all stairways, exits and entrances and provide some illumination in operational areas.

Para (650)

Security lighting shall be installed around the perimeter walls illuminating the external area and shall be controlled from the gatehouse.

23.5.1.

Schedule of Design Requirements

Para (651)

The lighting system shall include provision for ease of erection, maintenance, cleaning, lamp replacement and future extension. Lamp replacement and maintenance should, unless otherwise approved be possible without taking outages on main plant items.

Para (652)

Lighting apparatus shall be of top quality, designed to ensure satisfactory operation and service life under all variations of load, frequency and temperature. Sodium discharge lighting shall not be used except for road and security lighting.

23.5.2.

Key to Abbreviations L P.B T.S C W P M D F S A BH

Local switches S1, S2 etc. Socket outlets or fused spur circuits Pushbutton for remote control Time switch control Ceiling mounted Wall mounted Pole or earth mast mounted Recessed modular mounting Suspended Flush installation Surface installation Automatic on mains failure Behind ceiling diff

23.6.

Coding Systems

Para (653)

The Contractor shall when preparing drawings showing the respective designs use a code to identify each lighting fitting and socket outlet.

Para (654)

The code shall comprise letters and figures so compiled that the following information can be readily identified: • • • •

The lighting distribution board to which the fitting or socket outlet is connected. If connected to the normal supplies or to the emergency d.c. supplies. The circuit number and phase of the distribution board to which the fitting is connected. The sequence of the fitting in a particular circuit.

23.7.

Distribution Boards

Para (655)

The distribution boards and all component parts shall be manufactured and tested in accordance with the latest Standard and designed to suit the fault level of the transformers supplied. The Contractor shall demonstrate by calculation this has been complied with.

Para (656)

Each current carrying component shall be so designed that under continuous rated full load conditions in the climatic conditions at Site the maximum total temperatures permitted under the relevant Standards are not exceeded.

Para (657)

Each distribution board shall have a rustproof metal case of sheet steel with either a galvanised or enameled finish. The colour of the enamel finish shall match the colour of other switchgear. The metal casing is to be provided with a number of knock-outs or other


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approved form of cable entries corresponding to the circuit capacity of the distribution board and a suitable screened brass earthing stud. Para (658)

Busbars including neutral bar shall be of high conductivity copper ed to withstand all normal and fault condition stresses.

Para (659)

All busbars, neutral bars and primary conductors are to be PVC sleeved in respective phase and neutral colours.

Para (660)

Distribution boards for exterior use shall be galvanised and weatherproof.

Para (661)

Neutral bars shall have an appropriate number of ways relative to the size of the board. They shall have a rating not less than that of the associated phase busbars.

Para (662)

The metal surface adjacent to any live part and all spaces between phases shall be protected by barriers of fireproof insulation material.

Para (663)

The distribution boards shall be either single pole or triple pole and neutral types and shall be equipped with means to provide overcurrent protection to each circuit. This protection may comprise an HRC fuse or a miniature circuit breaker, both of which shall be removable without exposing live connections.

Para (664)

Fuse bases and bridges where used shall be of an approved non- hydroscopic insulation suitable for the receipt of HRC fuses.

Para (665)

Residual current circuit breakers shall be incorporated to protect all lighting circuits, socket outlets and supplies to appliances, etc. These shall comply with the requirements of the main electrical part of this Specification.

Para (666)

The current rating of the busbars in each distribution board is not to be less than the sum of maximum current rating of all outgoing circuits. The neutral connection for each circuit is to be direct to the neutral busbar.

Para (667)

Approved type title labels are to be fitted externally on the front cover of each distribution board giving details of the points controlled by each circuit. The circuit list shall be typed or printed stating the location of the equipment served, rating of the protective unit and the circuit loading. The lists shall be mounted on the inside of the cover door and shall be protected by an acrylic sheet slid into a frame over the circuit list, the list and cover to be easily removable to permit circuit modifications.

Para (668)

The cables feeding the distribution boards will be connected directly to the incoming isolator or neutral bar as appropriate unless otherwise indicated by the Specification.

Para (669)

Switchfuse units or isolators connected on the incoming side of a distribution board shall be mechanically attached to the board with solid copper electrical connections between the units. A suitable insulated barrier is to be supplied to prevent copper or carbon dust released under fault conditions ing from one unit to the other.

Para (670)

Distribution boards for use on direct current system shall be double pole types equipped with adequately rated fuses.

Para (671)

Mixed capacity boards shall be employed and all ors and time switches associated with the respective outgoing circuits shall be accommodated within the distribution board.

23.8.

Miniature Circuit Breakers

Para (672)

Miniature circuit breakers shall comply with the requirements of the main electrical part of this Specification.


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23.9.

Cables

Para (673)

Armoured cables shall be XLPE insulated, single wire armoured and polyvinyl chloride sheathed overall and be manufactured and tested in accordance with the requirements of BS.5467, 600/1000V grade or equivalent. The outer sheath shall be coloured black and incorporate flame retardant characteristics to meet the requirements of BS.4066 and IEC.332. Jute fillings will not be permitted. Cables shall comply with the requirements of the cable section of this Specification.

Para (674)

Each armoured cable shall be provided with separate Earth Continuity Conductor (ECC) of minimum half size of the phase conductor, coloured yellow/green.

Para (675)

Flexible type cables for pendant cords and final connections to fixed apparatus are to be butyl or silicone rubber insulated and sheathed manufactured and tested in accordance with the requirements of BS.6500, 300/500V or 300/300V grade as applicable.

Para (676)

The conductor is to comprise multi-strands of 0.25 mm wire. The number of strands are to be not less than 30 and in all cases of a number suitable for the protection rating of the respective circuits.

Para (677)

All cables used for lighting and small power shall have copper conductors.

Para (678)

The Contractor is to select conductor sizes for the respective final circuits to meet the following conditions:•

That the minimum conductor size for lighting circuits is to be 2.5mm2 and for socket outlets 4 mm2.

•

That the size is to be adequate for the current to be carried as set out in the cable manufacturers Specification.

•

That the size is sufficient to keep the voltage drop in the phase and neutral conductor to the farthest lighting or power point, under normal full load conditions to within the final circuit limit specified in BS7671. Diversity will not be allowed.

23.10.

Cable Terminations

Para (679)

Terminations for cables shall comprise compression type glands with armour and bonding clamps to meet the requirements of Type E1 to BS.6121 or equivalent and are to be designed to secure the armour wires, to provide electrical continuity between the armour and the threaded fixing component of the gland and to provide watertight seals between the cable outer sheath and gland and between the inner sheath and threaded fixing component. The glands are to project at least 10 mm above the gland plate to avoid moisture collecting in the cable crutch.

Para (680)

Earth bond terminal attachments are to be provided.

Para (681)

Terminations for rubber insulated cables are to comprise compression type glands where the function of the gland is to secure the outer sheath of the cable, in accordance with the requirements of Type A2 to BS.6121 or equivalent. A watertight seal is to be provided between the outer sheath and the gland.

Para (682)

Only one cable is to be terminated in each gland.

23.11.

Sealing and Drumming

Para (683)

Immediately after the works tests, both ends of all cables shall be sealed against the ingress of moisture, dirt and insects and the end projecting from the drum shall be adequately


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protected against mechanical damage during handling and shall be fitted with a pulling eye bonded to cores, sheath and armours. 23.12.

Conduit

Para (684)

The whole of the various installations described shall be carried out in screwed heavy gauge welded steel conduit or heavy gauge PVC conduit, at the discretion of the Engineer. No conduit less than 20 mm diameter will be permitted. Surface mounted Flush mounted

PVC switchrooms, battery rooms, i.e. painted blockwork. PVC relay control rooms which have a decorative finish

Para (685)

Steel conduits shall be manufactured in accordance with BS.4568, Part 1 or equivalent, heavy gauge screwed and welded Class B and shall be galvanised. Conduit fittings are to be manufactured of good quality galvanised malleable cast iron and of small circular pattern to BS.4568, Part 2 or equivalent, with internally tapped spouts minimum length 21 mm threaded to the correct length at inter-sections tees, draw through and stopends.

Para (686)

Conduit fittings of PVC shall be of the plain bore pattern suitable for a push-on compression type t and shall be sealed with a hard setting vinyl cement to prevent ingress of vermin, water, dust, etc. Inspection bends solid or normal bends elbows or tees are not to be used except with the approval of the Engineer.

Para (687)

Conduit runs shall, wherever possible, be concealed in ceilings, voids and walls, chases etc., and in rooms of secondary importance (with back outlet entries to switch boxes etc. especially on fair faced brickwork) otherwise the conduits shall be securely fixed to the surface of walls using heavy cast distance saddles. Where plastered finishes are called for, buried conduit systems shall be provided.

Para (688)

Where the system of wiring is concealed, the 'loop-in' system of conduit shall be used and the 'looping-in' boxes shall conform to BSS31, Class B3.

Para (689)

A separate insulated earth conductor, coloured yellow/green, shall be run in PVC conduits and such facilities shall be provided at all terminal points.

Para (690)

Wherever the installation is specified as being flame-proof, the conduit runs entering these areas shall have a barrier box inserted in the run immediately before the conduit es into the flame-proof area. All conduit work inside the flame-proof area shall be carried out with solid drawn galvanised conduit and all conduit fittings, sockets and accessories shall be galvanised and certified suitable for Group 1 hazard. At the completion of the wiring all machine faces on accessories shall be thoroughly cleaned and greased, prior to the screwing or bolting of all accessory cover plates into their final flame-proof secure position.

Para (691)

The ends of all steel conduits shall be reamered to remove all burrs or sharp edges after the screw threads have been cut. All dirt, paint or oil on the screw threads, the conduit, sockets and accessories must be removed prior to erection. All conduits shall be swabbed through prior to installation of cables.

Para (692)

The ends of the conduit shall butt solidly in all couplings. Where they terminate in fuseswitches, distribution boards, adaptable boxes, non-spouted switch boxes, they shall be connected thereto by means of smooth bore male brass bushes, compression washers and sockets. All exposed threads and all bends shall be painted with an aluminium spirit paint after erection.

Para (693)

All conduit and accessories, after being installed, shall be examined and all parts where the surface has been chipped or scratched shall be painted.


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Para (694)

All conduits shall be kept 80 mm clear of water, gas and other services. Should this prove impracticable, then they shall be properly bonded by means of pipe clamps or other device ensuring mechanically sound, electrically continuous connection.

Para (695)

The method of installing PVC conduit and fittings shall conform strictly to the manufacturer's recommendation. These recommendations shall be submitted when seeking approval to the system proposed. In general the clauses dealing with steel conduit shall apply.

Para (696)

PVC tube not exceeding 25 mm in diameter shall be bent cold by means of the appropriate spring and the tube shall be saddled as quickly as possible after bending. When bending larger sizes of tube, the tube must be heated in an approved manner until it is pliable. A 90o bend shall have a radius of not less than five times the outside diameter of the tube.

Para (697)

ts between conduits and conduit fittings shall be watertight and shall be made by means of a solvent adhesive as recommended by the manufacturer. Care should be taken to ensure that the tube is clean and free from damp and grease and in particular dust, mould and oil.

Para (698)

The Contractor shall provide PVC tube ends and flexible covers to prevent ingress of concrete grout into the tubing and boxes.

Para (699)

All bends are to be made on Site to suit conditions and not more than two right angle bends will be permitted without the interposition of a draw box. No tees, elbows, sleeves, either of inspection or solid type will be permitted. Generally long straight conduit runs from point to point shall have draw boxes installed at maximum intervals of 10 metres.

Para (700)

Deep boxes or extension rings on standard circular conduit boxes shall be used where necessary in order to bring the front of each box flush with the surface of the ceiling or wall. Where conduits are laid direct on the shuttering of the reinforced slab construction conduit extension rings or deep boxes shall be used to raise the run of conduit to between the top and bottom reinforcing. Galvanised draw wires or other approved types shall be provided where conduits are not be wired on completion or are to be wired by others.

Para (701)

All draw boxes and junction boxes shall be of ample size to permit the cables being drawn in and out. They shall be made of galvanised iron and the ting surface machined to ensure a dust tight t. All circular boxes shall be provided with long spouts internally threaded incorporating a shoulder for the proper butting of the conduit and a solid copper earth terminal tapped and screwed into the base of the box.

Para (702)

All conduit boxes shall be screwed on or in walls, ceilings etc. by countersunk wood screws of appropriate size. Holes in boxes shall be adequately countersunk to ensure the complete recession of the fixing screws. All inspection and draw-in boxes shall be provided with covers fixed by round head galvanised iron screws.

Para (703)

Where surface conduit is specified, it shall be fixed by means of distance saddles and shall terminate in raised back pattern conduit boxes. Surface conduits shall be bent or set to enter accessories, and where they turn through walls back outlet boxes shall be provided. Conduits shall be fixed at 1200 mm centres on vertical runs and 900 mm apart on horizontal runs.

Para (704)

Vertical conduit runs shall have saddles at 300 mm maximum from their points of emergence from floors or ceilings and the remaining saddles shall be fixed consistent with the requirements of spacing and appearance. Saddles shall be fixed on each side of every bend at 300 mm maximum from the point of intersection of the centre line conduit.

Para (705)

Conduits in ceiling cavities shall be ed independent of the suspended ceiling.

Para (706)

Where conduits cross expansion ts, the Contractor shall allow for the installation of expansion couplers at the positions of the expansion t and at right angles to it. He shall


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provide a bonding earth wire between each terminal fitted in the nearest conduit box each side of the coupler. Para (707)

All flexible metallic tubing shall be galvanised watertight pattern fitted with sweated brass adaptors. External earth conductors, wrapped around the tubing, shall be provided.

Para (708)

Where conduits are laid in slab floor etc., the Contractor shall arrange for a competent person to be in attendance whilst the concrete pouring or screeding operation is being carried out, in order to avoid damage being caused to the conduits and also to ensure that the conduit work is in sound condition, properly and efficiently maintained during this installation period.

Para (709)

Particular care should be taken when setting out conduit runs to outlet points where they are to be fitted to furniture, kitchen fittings, etc. The Contractor shall ascertain exact details of the furniture and fittings construction in order that all conduit work shall wherever possible be concealed.

Para (710)

Conduits installed in chases of walls and floors shall be firmly secured by wrought iron pipe hooks or crampets and these fixings shall in themselves be sufficient to hold the conduits in place. Conduits installed in chases shall be painted with one coat of bitumastic paint before erection and a further coat shall be applied to all accessible surfaces including the hooks and the crampets after erection.

Para (711)

Recessed conduits buried in plaster shall permit a full 6mm depth of cover over its entire length.

Para (712)

Provision shall be made for the tapping of condensed moisture.

Para (713)

Care shall be taken to prevent water, dirt or rubbish entering the conduit system during erection. Screwed metal caps or plugs shall be used for protecting open ends.

Para (714)

All conduit system shall be erected completely with all conduit accessories connected, they shall then be offered for inspection and approval by the Engineer before any cables are installed. Conduit boxes shall be fixed to the structure of the building independently of the conduit.

Para (715)

Where a conduit is exposed to different temperatures (either by surrounding air conditions or by virtue of the surrounding medium with which it is in ) at any particular time, the section of the conduit at the higher temperature shall be isolated from the section at the lower temperature by means of a conduit box filled with an approved permanently plastic compound, after completion and testing of all wiring. Such a condition would arise if a conduit running in a warmed building is run to exterior points.

Para (716)

Where galvanised conduit is specified, all conduit, accessories, switch boxes and all associated apparatus used in the installation must also be galvanised. Galvanised conduit shall be used when mounted outside a building, installed in floor chases subject to dampness or accidental flooding, or buried in the ground. Conduit system shall be weatherproof when erected outside a building. Exposed conduit threads shall be given a coat of zinc rich paint.

Para (717)

Conduit buried in the ground shall be wrapped with PVC self-adhesive tape half lapped. The taping shall be extended for a distance of 150 mm beyond the point where the conduit emerges from the ground. ts in galvanised conduit systems shall be made watertight using lead, aluminium paint and hemp and/or gaskets. The ts shall be partially screwed up before the paint and hemp are applied and hemp are applied to maintain continuity.

Para (718)

All adaptable boxes shall be grey iron pattern unless otherwise specified. Where adaptable boxes are fitted flush, the cover plates shall be heavy gauge metal with 12 mm overlap on all sides. The internal depth of a box shall be not less than 40 mm.


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Para (719)

Covers shall be secured by a screw at each corner and by additional screws as necessary to provide a maximum spacing of 300 mm between adjacent screws. Fixing screws shall be brass (round or cheese head).

Para (720)

Covers for boxes shall be of the same material as the box. For boxes mounted in weatherproof situations, the cover shall have a machined surface around the perimeter mating with a similar machined surface on the box and shall be complete with a gasket.

Para (721)

Every flush outlet box to which a luminaire pull cord switch or similar is to be fitted shall be fitted with an approved type of break t ring.

23.13.

Cable Trunking

Para (722)

Where trunking is specified it shall be constructed of 1.65 mm minimum thickness zinc coated mild steel or PVC and shall have a removable cover throughout its length with centre screw latch fixings. Trunking shall be rigidly fixed and supplied complete with purpose manufactured fittings, connectors, dividers, flanges, cable retaining clips, racks and copper earth continuity links. As an alternative if approved, a proprietary brand of heavy duty plastic trunking may be acceptable. When submitting details for approval, full installation instructions as recommended by the manufacturer shall be included in the details.

Para (723)

All cables installed in trunking shall be labeled and identified in an approved manner. Clips shall be at 600 mm centres. Vertical cable trunking shall be fitted with cable pin racks arranged to avoid any strain on the cables.

Para (724)

All trunking shall be rust proofed, primed and painted and fixed at intervals not greater than 1,000 mm.

23.14.

Cable Trays

Para (725)

Cable trays where required as part of the Contract supply are to be the perforated galvanised sheet type.

Para (726)

Trays are to have upturned edges and be of a width suitable for the number of cables to be ed and are to be supplied with purpose- made galvanised steel brackets suitable for mounting from the building structure. External cable trays shall be provided with covers.

23.15.

Cable ting

Para (727)

The Contractor shall be responsible for the sealing and ting of all cables supplied and installed as part of this Section of the Contract.

Para (728)

Straight ting of cables is not permitted without the written consent of the Engineer.

23.16.

ors

Para (729)

ors shall comply with British Standard 5424 or equivalent and shall be of the electrically held-in types contained in heavy gauge sheet steel cases suitable for mounting. Each or shall be continuously rated and suitable for thirty inductive switching operations per hour.

23.17.

Switches and Pushbuttons

Para (730)

Switches shall be rated for 15 amp and shall be single pole types and be provided with an earth terminal.

Para (731)

Switches shall be one way, two-way or intermediate as required and where mounted together they shall be fitted in a common box.


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Para (732)

Switches for use in areas designated for surface installation shall be quick-make-quickbreak fixed grid industrial types mounted in galvanised malleable iron boxes with protected dolly and arranged where necessary for multigang switching.

Para (733)

Switches for use in areas designated for flush installation shall be micro-break types fixed to white plastic cover with metalic louver plates and mounted in galvanised steel flush type boxes.

Para (734)

Switch-boxes shall be galvanised and fitted with screwed stainless steel front plates having a 6 mm overlap minimum for flush installations. They shall be suitably barriered and labelled where two phases are connected in the same box.

Para (735)

Switches mounted externally shall be of weatherproof pattern to IP65 level.

Para (736)

Where d.c. emergency lighting circuits are to be switched, double-pole quick make, quick break switches with pillar type terminals and earthing straps shall be provided.

Para (737)

Switches shall be mounted 1.4 m above finished floor level.

Para (738)

Pushbutton switches shall either be flush or surface types contained in galvanised steel boxes and be single pole rated for 5 Amps. Pushbuttons shall be made of non-hydroscopic material, be non-swelling and so fitted as to avoid any possibility of sticking.

Para (739)

The terminals for all switches shall be adequate to accommodate 2 conductors each a minimum of 2.5 mm2 and 4mm² for small power.

23.18.

Lighting Fittings

Para (740)

Illustrations and/or samples of all lighting fittings which the Contractor proposes to purchase shall be submitted to the Engineer for approval before issuing any sub-orders.

Para (741)

Lighting fittings for interior and exterior use are to be manufactured and tested in accordance with the appropriate sections of BS.4533, IEC 162 or equivalent and together with all components are to be suitable for service and operation in the tropical climate stated.

Para (742)

Each fitting is to be complete with all lampholders, control gear, internal wiring, fused terminal block, earth terminal and reflectors or diffs as specified. The design of each fitting is to be such as to minimise the effect of glare and such that the ingress of dust, flies and insects is prevented, where open type fittings are used it is to be impossible for insects to become lodged therein.

Para (743)

The control gear for use with fluorescent lamps and is to be quick or resonant start type without starters. Chokes are to be impregnated and solidly filled with polyester resin or other approved high melting compound and are to be manufactured to restrict the third harmonic content to less than 17% of the uncorrected current value and are to be silent in operation.

Para (744)

The built-in ballast units shall comply with IEC Publication No. 82 and shall include radio interference suppressors and capacitors to correct the fitting power factor to a minimum of 0.95 lagging as per DEWA's wiring regulations. Control gear noise levels shall be minimal.

Para (745)

Fittings shall be supplied complete with closed end vitreous enameled metal reflectors or totally enclosed opal plastic diffs which shall be fully interchangeable.

Para (746)

Dispersive reflector fittings suitable for mercury bulb fluorescent or tungsten filament lamps shall be of heavy gauge sheet steel finished vitreous enamel. They shall be fitted with anti-vibrators and arranged for conduit box mounting, direct or pendant, on galvanised ball and socket dome type lids.


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Para (747)

Bulkhead fittings shall have cast bases tapped for conduit entry, hinged bezels, heat resisting prismatic glasses fitted with neoprene gaskets and porcelain lampholders. Circuit cable shall not be connected direct to bulkhead fittings but shall terminate in a fixed base connector mounted in a conduit box adjacent to the fitting. Final connections to each fitting shall be carried out with silicone rubber covered cable. All bulkhead fittings shall be watertight pattern.

Para (748)

Internal connections are to comprise stranded conductors not less than 0.75 mm2 covered with heat resistant insulation to the requirements of BS.6500 or equivalent. All internal wiring is to be adequately cleated to the fitting casing with an approved form of cleat. The finish of fittings for interior use is to be impervious to deterioration by atmospheric reaction. Fittings for exterior use shall have a vitreous enamel, natural aluminium or galvanised finish according to the manufacturer's standard product.

Para (749)

Lampholders for tungsten lamps up to 150 watts shall be brass or porcelain BC type and for higher ratings shall be ES or GES type according to size. Fittings for housing tungsten lamps exceeding 150 watts rating are to be provided with an approved method of dissipating heat from the lamp cap and terminal housing.

Para (750)

Lampholders as applicable are to be suitable for the lamp specified.

Para (751)

Lighting fittings are to be of the type description as generally set out in the schedule appended to this section of the Specification. The type references used are to be repeated in the Schedules and on the drawings.

23.19.

Lamps

Para (752)

The Contract includes the supply and erection of all lamps and tubes necessary to complete the installation.

Para (753)

Fluorescent lamps shall be manufactured and tested in accordance with British Standard 1853. IEEC 81 or equivalent shall be bi-pin types and shall have colour rendering values of X = 0.335 and Y = 0.342 (i.e., Colour 2) on the CIE chromaticity scale.

Para (754)

Tungsten lamps shall be manufactured and tested in accordance with BS.161 or equivalent and shall be bayonet cap for lamps up to and including 100 watts. Lamps rated for 150 watts and higher shall have edison screw caps. Low wattage lamps used in exit signs and emergency lighting units may be small or miniature edison screw.

Para (755)

Discharge lamps shall be manufactured and tested in accordance with British Standard 3677 or equivalent. Mercury vapour lamps shall be fluorescent types having a 10% red ratio colour correction, whenever used.

23.20.

Socket Outlets and Fused Spur Outlets

Para (756)

Each socket outlet shall comply with the requirements of the British Standard 1363 or equivalent and shall be the interlocked shuttered and switched types arranged for surface or flush mounting in single or multigang units as appropriate.

Para (757)

Each fused spur outlet shall be equipped with double pole isolator, a fuse to British Standard 1362 or equivalent and where required front entry for flexible connection.

Para (758)

Each socket outlet and fused spur outlet shall be equipped with a galvanised metal box with earth terminal.

Para (759)

Each group of five socket outlets is to be provided with a matching fused plug top. 3 nos. of 63A sockets shall be provided in the GIS room at suitable location for the gas handling plant. There shall be a separate heavy duty industrial type socket outlet of 200 Amps rating with plug to be provided in the 132Kv GIS Room for HV testing of GIS.


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Para (760)

All socket outlets for exterior use shall be galvanised and weather-proof and be equipped with screwed dustproofed cap attached to the socket by means of a chain.

23.21.

Time Switches

Para (761)

Time switches for use with lighting systems shall be the synchronous motor wound types protected by a suitably rated fuse for 220 volts operation with a nine hour reserve spring and are to be fitted with a twenty-four hour hand set dial two "off" and two "on" levers and manual operation pushbutton. The main s shall be rated for 20 Amps on a 220 Volt 50 Hz A.C. supply.

Para (762)

Time switches shall be suitable for mounting in the distribution boards supplying the circuits to be controlled.

23.22.

Poles

Para (763)

Lighting poles shall be tapered of hot dipped galvanised steel with bituminous preservative inside and outside at the base and shall be approved by the Engineer.

Para (764)

Each pole shall be equipped with a base section compartment of 470 mm by 150 mm to house an inspection trap, lockable door, fused cutout, cable entry and terminations for both the incoming and outgoing power cables and secondary cables feeding the light sources.

Para (765)

Poles for substation lighting shall the floodlights at minimum 4.5m above ground level, and poles for access roadway lights shall the lanterns at 10 m above ground level.

Para (766)

The Contractor shall ensure each pole is provided with foundations suitable for the ground conditions occurring at each Site.

23.23.

Interior Installations

Para (767)

Wiring for the lighting and socket outlet installations shall comprise PVC cables drawn into conduits attached to walls, structural or roof steelwork or ceilings as appropriate.

Para (768)

Surface and flush type installations are required according to the particular area as indicated in the schedule appended to this section.

Para (769)

In areas where flush type installations are indicated the wiring shall be drawn into conduits buried under wall finishes or concealed above ceilings as appropriate.

Para (770)

All fixings shall be of a type approved by the Engineer and all metalwork used shall be galvanised. Fixings to structural steelwork shall be with purpose made brackets or clamps, the drilling of structural steelwork will not be permitted.

Para (771)

Cleats with two screw fixings shall be used for ing conduits at not greater than 2m intervals.

Para (772)

All switchboxes, socket outlet boxes and items of a similar type shall be fixed with two screws or bolts.

Para (773)

Switches and pushbuttons for lighting circuits shall be mounted at 1400mm above finished floor level. Socket outlets shall be mounted 500m above finished floor level but those for use with workshop benches shall be mounted 150 mm clear of the bench working surface and in basement should be 750mm above finished floor level.

Para (774)

Lighting fittings shall be attached to ceilings, walls, trunking or roof steelwork or suspended therefrom as appropriate.


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Para (775)

Where fittings are to be suspended, rod type suspension units shall be employed.

Para (776)

Final connections to all suspended lighting fittings shall be with heat resistant flexible cable terminated in porcelain clad connectors in the ceiling or junction box which shall also terminate the main circuit cable. The cable length shall be such that the suspension unit s the full weight of the lighting fittings.

Para (777)

Where recessed type lighting fittings are to be installed suspension units shall be used to prevent the weight of the fittings being applied to the suspended ceiling. It shall be possible to carry out maintenance from the underside of the fitting without disturbing the false ceiling. To facilitate this need the final connection to each fitting shall be with heat resistant flexible cable from a plug in type ceiling rose mounted above the false ceiling.

Para (778)

All cables not contained within conduit for their whole route shall be terminated with a cable gland.

Para (779)

Where lighting fittings are mounted direct on walls or ceilings the main circuit cables may be connected into the fitting terminal block. Where terminal blocks do not exist within the lighting fitting flexible heat resistant cable shall be used connected to a separate junction box.

Para (780)

Earth continuity shall be maintained throughout the entire wiring installation with separate insulated earth continuity conductors of adequate cross-section ultimately connected to a common earth terminal at the respective distribution board.

Para (781)

Within the interior installation adequate provision shall be made for connection to small ventilating fans.

Para (782)

Each and every trunking route shall be bonded across all ts with external copper bonding links supplied for the purpose.

23.24.

Exterior Installation

Para (783)

Exterior substation lighting fittings shall be attached to substation walls at high level or pole mounted as appropriate. Security lighting round the perimeter wall/fence is to be provided.

Para (784)

Cables to exterior lighting shall be laid direct in ground, laid in concrete trenches or cleated to buildings structures as appropriate to the route requirement. The cables shall be terminated at a cut-out located at the base of each . Wiring between the cut-out and the control gear or lantern shall be with multicore cable run within poles or with cable drawn into galvanised steel conduit attached to the ing structure.

23.25.

Essential Services

Para (785)

A minimum of fifty per cent of the lighting and medium and low voltage power distribution, in all areas, shall be arranged to be fed from the Essential Supplies Board on failure of the normal ac supply.

23.26.

Emergency Lighting

Para (786)

Emergency lighting shall comprise lighting fittings of the types as indicated in the schedule appended to this section of the Specification.

Para (787)

The system shall be so arranged that on failure of the normal a.c. supplies to the lighting installation the emergency lighting system will automatically be switched on. Other than those of the "on demand" type, all emergency lighting shall be switched "off" 5 minutes after restoration of normal supplies. Each emergency lighting unit shall have a minimum 3 hour rating.


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Para (788)

Sufficient fittings of Type E3 shall be provided in each room to enable the rooms and building to be evacuated safely.

Para (789)

In addition in designated working areas emergency manually switched lighting to give not less than 30 lux shall be provided utilising type E4 fittings. Switches shall be labeled to the approval of the Engineer.

Para (790)

The emergency lighting shall be supplied from a separate 110V battery of `L’ type independent from the main substation battery, and shall have a back up time of 5 hrs and its own separate battery charger. Other details regarding battery, battery charger and control distribution board, mounting and other items shall be as per specification detailed in 1.5.1.6.6.01.

23.26.1.

Portable Emergency Lighting

Para (791)

Emergency portable rechargeable hand lamps shall be of the wall mounting charger/lamp type. The lamp battery shall have a 4AH capacity with a discharge period in excess of 3 hours. The lamp shall be provided with main and auxiliary bulbs which can be switched by an ON/OFF switch. A charge function monitoring LED is to be included. The hand lamps shall be installed in all areas of the substation. •

The battery in the portable emergency wall mounted light should be housed in a vertical position and should not be in horizontal position.

•

In addition to the lamp control switch, there shall be an isolation switch, which when kept in “off” position shall prevent its working (discharging of battery) even in case of AC supply failure.

•

Portable emergency lighting shall be provided in the following areas but not limited to : GIS Room 11Kv/22 kV Switchgear rooms Control room Battery, LVAC, DC Charger, Cap. Bank Room, Security Room, Telecommunication / Scada Room, Fire Pump Control Room 132kV & 11kV/22 kV basements, Control Building Corridor

2 nos. (one at each end) 2 nos. each room (one at each end) 2 nos 1 no. each room

2 nos. in each area.

23.27.

Telephone System

Para (792)

A complete conduit/duct system shall be provided throughout the building including the telephone cables etc.of both commercial and scada telephone to be run to the proposed extension points. A layout drawing showing the proposal location shall be submitted for Engineer’s approval.

23.28.

Schedule of Lighting Fittings and Socket Outlets

Para (793)

Lighting fittings described in this Schedule shall also meet the general requirements of the Clause for Lighting Fittings of this Specification. TYPE F1

Shall indicate a basic channel complete with control gear and lampholders for one 1500 mm long fluorescent lamp, equipped with an open ended metal reflector having upward light slots.


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TYPE F2

Shall indicate a fitting which shall comply generally with the description for Type F1 but be equipped for use with two 1500 mm lamps.

TYPE F3

Shall indicate a recessed modular fitting louvre type approximately 1200 mm long 600 mm Wide suitable for mounting in a suspended ceiling. The metalwork and trim are to comprise a rigid welded unit so arranged as to be invisible when erected complete with controller. The fitting is to be equipped with a pre-wired removable gear tray and adjusting facilities to enable leveling relative to the ceiling to be carried out after erection. The assembly is to be complete with control gear and lampholders for two nos. 1200 mm long fluorescent lamp.

TYPE F4

Shall indicate a fitting which shall generally comply with the description F3 but with three nos.1200 m long fluorescent lamps.

TYPE F5

Shall indicate a dust-tight weatherproof and vapour resistant fitting, having a gray polyester fibre glass reinforced chassis containing the control gear and having lampholders for one or two 1500 mm fluorescent lamp. The fitting shall be complete with a vacuum formed acrylic diff which is secured to the body with injection molded toggles and sealed with a neoprene gasket.

TYPE F6

Shall indicate a weatherproof bulkhead fitting with a cast aluminium base and vandal resistant diff equipped with control gear and lampholders for two 300 mm 8 watt fluorescent lamps.

TYPE E1

Shall indicate a self-contained, self-sustained (normally off) emergency lighting unit, complete with integral batteries and control gear, with the words "EXIT" in white letters on green background in English and Arabic. It shall be energised from the batteries under mains failure conditions. The mains failure device shall be sensed by an unswitched phase connection from the local lighting circuit.

TYPE E2

Shall indicate a self contained, self-sustained (normally off) wall mounted emergency lighting unit comprising a pilot light and two 50 watt spotlights complete with control gear. The pilot light shall be energised under mains failure conditions with manual "on demand" switches for the spotlights. The mains failure device shall be sensed by an unswitched phase connection from the local lighting circuit.

TYPE E3

Shall indicate a self-contained, self-sustained, maintained type wall or ceiling mounted 60 or 40 watt emergency fluoresent lighting unit complete with control gear. The lamps shall be energised from normal supply or from emergency supply at all times.

TYPE E4

Shall indicate a 60 or 40 watt 110V DC wall or ceiling mounted emergency fluoresent lighting unit which shall be manually switched and be similar to type E3.

TYPE H1

Shall indicate forward throw floodlight fitting comprising a sheet steel vitreous enameled or spun aluminium reflector housing a 250W high efficiency mercury Vapour lamp. The fittings to be complete with wall mounting bracket.

TYPE H2

Shall indicate a semi-cut off roadway lantern with housing manufactured from a one piece LM6 aluminium alloy casting enameled white internally and equipped with reflector bowl of heat resisting glass, all suitable for housing the lampholders and control gears for 250 watt SON (High Pressure Sodium Vapour) Lamps. The fitting to be equipped with pole arm suitable to give an outreach of 1


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metre. TYPE S1

Shall indicate a 13 Amp single or double gang flush mounted switched socket outlet.

TYPE S2

Shall indicate a 13 Amp single or double gang surface mounted switched socket outlet.

TYPE S3

To comprise an ironclad one gang heavy duty 4 pole interlocked fuseswitched socket outlet with scraping earth connection suitable for use on a 380 Volt 3 phase 4 wire 50 Hz for 180 A. Each socket is to be supplied complete with three HBC fuses and cable box with 2 glands, suitable for terminating a PVCWPVC cable. The socket shall be fitted with a screwed dustproof cap attached to the top of the socket by means of a chain. Matching plugs to be provided in each socket.

TYPE S4

Shall indicate a 16 amp 3 phase 4 wire switched socket outlet with plug flush mounted. (a) shall indicate a 32 amp 3 phase 4 wire switched socket outlet with plug flush mounted

TYPE S5

300 ampere TP & N 5 pin heavy duty interlocked metal-enclosed switch sockets weatherproof to IP55 with brass screw cover and plugs for installation in each transformer enclosure. The socket outlet shall be compatible with those required for oil treatment plant supply. The 300A, TP & N, 5 pin, heavy duty interlocked, metal enclosed socket outlet shall have stainless steel enclosure tested to IP 55. 3 Nos. 63 Amps, 3 Phase, 5 Pin, 400V, Sockets shall be provided in the GIS room (one at each end and one at middle) as specified in 132kV switchgear specification, document no.1.5.1.2.2.01. 1 no. 13 Amps, 1 Phase, 3 Pin, 230V socket shall be provided in each IDT & ET rooms for tapping supply for testing equipments and blower. Sockets shall be as per clause 23.20 for exterior use.

23.29.

Table II

Para (794)

Schedule of Lighting Requirements for Substations and Control Building. Service Illuminance

Type of Fittings

Type of Fixing

Type Outlet Control and Switch

socket Type No.

Type of Installation

F

Lux

Index

Main Emer.

Control Relay Room Behind s Offices SCADA PLC Rooms Battery Rooms LV AC and DC Rooms Toilets Main Transformer Compounds

300 100 300 300 150 250 150 120

16 16 25 -

F3 E1/E2 E3/E4 F3 E3 F3 E3/E4 F5 F2 E4/E3 F2 E3 F5 E4

M

L/A

M M C C -

L/A L/A L L/A L/A L

Grounding transformer compounds Foyer ages Corridors, Stairs Roadways & External Areas Swithrooms 132KV:

120

F5 E4

-

L

S1-4 S4-1 S1-2 S1-2 S2-1 S1-1 S5-2 S2-1 S4(a)-1 * S-3-1

L/A

S1-2

F

T.S.

- -

-

L/A

S2-4

S

200

22

F3 E1/E2

20

-

H2 E4

M E3 P.B

300

-

F2 E1/E2

C/D


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F F S S F S

S


1.5.3.1.0.01-Rev.10

Civil Works

33KV:11KV:22kV NE:415V: DC Cable basements AC plant room and power supplies Store room

E3/E4 150 300 150

-

F5 E1/E2 F2 E2

C C/D

L/A L/A

S2-4 S2-2

S S

F2 E3

C

L/A

S2-1

S

Para (795)

For key see Lighting Requirements and Schedule of Lighting Fittings and Socket Outlet Clauses.

Para (796)

*The 300A, TP & N, 5 pin, heavy duty interlocked, metal enclosed socket outlet shall have stainless steel enclosure tested to IP 55.

24.

CRANES

Para (797)

Travelling crane(s) shall be provided for the 132kV GIS switchgear building. The crane(s) shall be capable of lifting and accurately positioning all loads ranging from full crane rated capacity to at least 10% rated capacity. The cranes shall be furnished with one hoist.

Para (798)

The Contractor shall provide crane(s) of approved capacity to handle the heaviest load to be encountered during normal maintenance and repairs and the heaviest indivisible load during initial erection or when carrying out extensions. It shall be capable of lifting at least 5 tonnes.

Para (799)

The crane shall have speeds under full load of: CRANE Hoisting Cross Travel Long Travel Creep speed of 25% of operating speed.

SPEED 2 metres/minute 10 metres/minute 20 metres/minute

Para (800)

The bridge of gantry trolley and hoist movements shall be controlled by suitable reversible controllers. The bridge or gantry trolley and hoist control schemes shall permit variable speeds in both directions of travel. Limit switches shall be provided at end limits of bridge, trolley and hoist travel. The Control station shall be of the pendant type. If the switchgear design and trunking make the use of a pendant suspended from the trolley impractical, a pendant which can be plugged into stations at selected points around the switchroom should be provided with an adequate lead length. These stations shall be located such that safe control of the crane for all functions can be carried out at the front, rear or top of the switchroom as required by the design.

Para (801)

The electrical equipment shall consist of one motor for each crane motion, all of them provided with brakes; controllers, resistors, magnetic ors, overload protection and limit switches; all complete with hardware, insulators and any other equipment necessary for proper operation of the crane. The crane shall be so designed so as to guarantee fall-safe and satisfactory operation. Brakes shall be able to arrest the heaviest load carried at any position and hold it.

Para (802)

A factor of safety of 1.5 times the maximum working load is to be taken into for all stress calculations and also shock loading.

Para (803)

The bridge, trolley and hoist controllers of the crane shall each have five positions as follows: two in the forward or raising direction, two in the backward or lowering direction and one off position. Bridges and trolleys shall be fed from current collectors or by means of cables adequately ed and provided with self-winding reels. Stepless control will be accepted.


84 of 87


1.5.3.1.0.01-Rev.10

Civil Works

Para (804)

The crane bridge shall be of double beam construction using I-section trestle or box type , connected rigidly to the bridge trucks.

Para (805)

A permanent service platform running the full length of the bridge shall be fitted to provide access to all roof lights and fire detector equipment etc. The floor of the platform shall be at such a height that a person can travel down the shop without risk or danger from any overhead structure or roof beam. The platform shall be fitted with a safety rail but shall not obstruct access to hoist travel mechanism or crane lift. Local control facilities shall also be provided.

Para (806)

Two lights shall be fitted to the trolley to illuminate the crane hook.

Para (807)

The rails shall be fitted with steel stops and the end carriage equipped with spring buffers on either side.

Para (808)

Design drawings shall show details of the gears, bearings, drums, sheaves, trucks, wheels, trolley drive, rails, stops, cables, hooks, rivets, bolts, lubrication and marking.

Para (809)

Permanent means of access to the hoisting and travelling mechanism and a fixed crane servicing platform shall be fitted to the building.

Para (810)

The crane and all associated equipment shall be painted yellow. BSS 381 C colour 356 Golden Yellow with safe working load clearly painted on the crane beam in black.

Para (811)

The main supply switch shall be 3-pole and neutral and is to be 3 position i.e. ON/OFF/EARTH. In the earth position the crane and downshop leads will be earthed. The switch shall be lockable in both OFF and EARTH position.

25.

DATA SHEET

Para (812)

For convenience certain basic design principles and dimensions are listed below. This is not an exhaustive list and reference should also be made to the Technical Specification and other Schedules as appropriate. The Contractor is required to adhere strictly to the principles/dimensions listed, unless agreed otherwise in writing by the Engineer. Should alternative greater dimensions be indicated on tender drawings, these shall take precedence.

Para (813)

Minimum dimensions for equipment etc. in buildings: -

Para (814)

•

Rear of /equipment to adjacent wall - 1.0 metre (Except for items intended for "back to wall" mounting).

•

Rear of /equipment to front of adjacent /equipment at east 1.5 metres.

•

Front of /equipment to front of other /equipment when facing each other depth of withdrawable unit to be turn 90 plus 2.0 metre at lest.

•

Any outer part of enclosed switchgear, motor or generator on own baseplate to wall or other equipment - 1.0 metre. For switchgear which may be withdrawn from its housing, this dimension shall be taken from the front of the truck in its fully withdrawn position.

•

Allowance to included for access to plant front and rear for fire appliances.

•

Safety clearances according to B.S. 7354.

Minimum number of doors and means of access: -


85 of 87


1.5.3.1.0.01-Rev.10

Civil Works

• • • •

Control and relay rooms - one set of double doors plus one single door at opposite ends of room. HV Switchrooms as for (a). Doors to open outwards with handle. Corridors running complete length of building - double doors one end, single door other end. Cable tunnels - two access hatches at opposite ends of tunnel.

26.

LIST OF REFERENCES

26.1.

Civil Works BS12 BS 497 BS 729 BS 812 BS 882 BS 1610 BS 1722 BS 1881 BS 2573 BS 3148 BS 4027 BS 4102 BS 4131 BS 4248 BS 4514 BS 4550 BS 4660 BS 5328 BS 5385 BS 5481 BS 5572 BS 5930 BS 6031 BS 6150 BS 6297 BS 6319 BS 6367 BS 6399 BS 6431 BS 6515 BS 6575 BS 6949 BS 8004 BS 8110 BS 8204 BS 8301 BS 3 IS 1893 ACI 305.77 CIRIA SP31 ASTM C114 ASTM C227 ASTM C289


Portland Cement Cast iron and cast steel Hot dipped galvanised coatings on iron and steel articles Testing aggregates Aggregates from natural sources for concrete Materials testing machines and force verification equipment Fences. Pt10.Anti-intruder chain link fences Testing concrete Rules for the design of cranes Methods of test for water for making concrete Sulphate-resisting Portland cement Steel wire and wire products for fences Terrazzo tiles Supersulphated cement PVC-U soil and ventilating pipes, fittings and accessories Methods of testing cement Unplasticised PVC-U pipes and fittings of nominal sizes 110 and 160 for below ground gravity drainage and sewerage Methods of specifying concrete Wall and floor tiling Unplasticised PVC pipe and fittings for gravity sewers for sanitary pipework for site investigations for earthworks for painting of buildings for design and installation of small sewage treatment works and cess pools Testing of resin compositions for use in construction for drainage of roofs and paved areas Loadings for buildings: Pt.1 for dead and imposed loads, Pt.3 for imposed roof loads Ceramic floor and wall tiles Polyethylene damp-proof courses for masonry Fire blankets Bitumen-based coatings for foundations Structural use of concrete In-situ floorings for building drainage Chap.V Pt.2 Code of basic data for design of buildings: wind loads Earthquake resistant design of structures Hot weather concreting Guide to concrete construction in the Gulf region Chemical analysis of hydraulic cement Cement aggregate; test by mortar bar method for potential alkali reactivity Potential alkali reactivity of aggregate; test for Portland cement concrete

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1.5.3.1.0.01-Rev.10

Civil Works

ASTM C342 ASTM C586 BCA

Cement aggregate; test for potential volume changes Potential alkali reactivity of aggregates - rock cylinder test for carbonate rocks Publication 97.303 for laying precast concrete block pavements

26.2.

Lighting and Small Power

Para (815)

Code of Practice Regulations for Electrical Equipment in Buildings 15th Edition. Institution of Electrical Engineers. BS 6004 BS 6346 BS 6500 BS 6121 BS EN 60947 BS 4533 BS 3677 BS 1363 BS 1362 BS 4568 BS 4066 IEC 60332


Specification for PVC insulated cables (non armoured) for electric power and lighting Specification for PVC insulated cables for electricity supply Specification for insulated flexible cords and cables Mechanical cable glands Specification for control gear for voltages up to and including 1000V a.c. and 1200V d.c Luminaries Specification for high pressure mercury vapour lamps Specification for 13A fuse plugs and switched and unswitched socket outlets Specification for general purpose fuse links for domestic and similar purposes (suitable for use in plugs) Specification for steel conduit and fittings with metric threads of 150 form for electrical installation Test on Electric cable under fire conditions

87 of 87


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