SPECIFICATIONS - Kericho County · iii. Square (face) the pipe ends using the facing tools on the...

SPECIFICATIONS

Contents

SPECIFICATIONS ......................................................................................................................................................... 1

SECTION 1 PIPES AND FITTINGS ........................................................................................................................ 6

1.1 GENERAL .................................................................................................................................................... 6

1.2 MATERIALS ................................................................................................................................................. 6

1.3 WORKMANSHIP ........................................................................................................................................ 11

1.4 PAYMENT .................................................................................................................................................. 11

SECTION 2 VALVES, STOPS AND HYDRANTS .................................................................................................. 12

2.1 GENERAL .................................................................................................................................................. 12

2.2 MATERIALS ............................................................................................................................................... 12

2.3 SPARE PARTS ........................................................................................................................................... 14

2.4 WORKMANSHIP ........................................................................................................................................ 14

2.5 PAYMENT .................................................................................................................................................. 14

SECTION 3 – CONCRETE ........................................................................................................................................... 15

3.1 SCOPE AND STANDARDS ............................................................................................................................... 15

3.2 CLASSIFICATION OF CONCRETE ........................................................................................................... 16

3.3 CEMENT .................................................................................................................................................... 17

3.4 WATER .............................................................................................................................................................. 19

3.5 AGGREGATES ................................................................................................................................................. 19

3.6 ADMIXTURES ............................................................................................................................................ 21

3.7 DESIGNED MIXES ..................................................................................................................................... 23

3.8 NOMINAL MIXES .............................................................................................................................................. 24

3.9 MIXING .............................................................................................................................................................. 27

3.10 TRANSPORTING OF CONCRETE .................................................................................................................. 28

3.11 READY MIXED CONCRETE ...................................................................................................................... 28

3.12 CONSISTENCY OF CONCRETE..................................................................................................................... 30

3.13 PREPARATION OF FOUNDATIONS .............................................................................................................. 30

3.14 PLACING OF CONCRETE ......................................................................................................................... 30

SECTION 4 CONCRETE GROUND LEVEL RESERVOIRS (GLR) ........................................................................ 33

4.1 GENERAL ......................................................................................................................................................... 33

4.2 SITE WORKS ............................................................................................................................................. 33

4.3 EXCAVATION ............................................................................................................................................ 33

4.4 PREPARATION OF GLR FOUNDATIONS ................................................................................................ 33

4.5 BLINDING LAYER ..................................................................................................................................... 34

4.6 FOUNDATIONS AND FLOORS ................................................................................................................. 35

4.7 WALLS OF R.C. RESERVOIRS ................................................................................................................. 35

4.8 COLUMNS ................................................................................................................................................. 35

4.9 ROOFS ....................................................................................................................................................... 35

4.10 VALVE AND DRAIN CHAMBERS .............................................................................................................. 35

4.11 JOINTS ....................................................................................................................................................... 36

4.12 PIPES AND FITTINGS ............................................................................................................................... 36

4.13 METALWORK ............................................................................................................................................ 36

4.14 DITCHES AND TRENCHES ....................................................................................................................... 37

4.15 SURFACES IN CONTACT WITH EARTH .................................................................................................. 37

4.16 TESTING OF RESERVOIRS ...................................................................................................................... 37

4.17 DISINFECTION OF RESERVOIRS ............................................................................................................ 38

4.18 PLACING GRAVEL .................................................................................................................................... 38

SECTION 5 ELECTRICAL AND MECHANICAL WORKS............................................................................................. 39

5.1 SCOPE OF CONTRACT ............................................................................................................................ 39

5.2 DEFINITIONS ............................................................................................................................................. 39

5.3 REGULATION, STANDARDS, MATERIALS AND WORKMANSHIP ........................................................ 40

5.4 DESIGN AND STANDARDIZATION .......................................................................................................... 41

5.5 PACKING TRANSPORT AND STORAGE OF MATERIALS AND PLANT ................................................. 41

5.6 CONTRACT PERIOD AND PROGRAMME ................................................................................................ 42

5.7 TENDER DRAWINGS ................................................................................................................................ 42

5.8 WORKING DRAWINGS ............................................................................................................................. 43

5.9 CONTRACT DRAWINGS ........................................................................................................................... 44

5.10 RECORD DRAWINGS (AS-BUILT DRAWINGS) ....................................................................................... 44

5.11 AMBIENT CONDITIONS ............................................................................................................................ 44

5.12 SCHEDULES OF TECHNICAL INFORMATION ........................................................................................ 44

5.13 COPIES OF ORDERS ................................................................................................................................ 45

5.14 STANDARDIZATION ................................................................................................................................. 45

5.15 FOUNDATIONS AND BUILDING WORKS ................................................................................................ 45

5.16 INSPECTION AND TESTS AT MANUFACTURER'S WORKS................................................................... 45

5.17 ERECTION AND CHECKING OF WORK ................................................................................................... 46

5.18 SUPERVISION AND LABOUR................................................................................................................... 46

5.19 SPECIALIST SUBCONTRACTORS .......................................................................................................... 46

5.20 SPECIAL TOOLS ....................................................................................................................................... 47

5.21 INSTALLATION, OPERATING AND MAINTENANCE MANUALS ............................................................ 47

5.22 SPARE PARTS .......................................................................................................................................... 48

5.23 LABELS AND PLATES .............................................................................................................................. 49

5.24 DUST, INSECT AND VERMIN PROOFING ................................................................................................ 49

5.25 ALTERNATIVES ........................................................................................................................................ 50

5.26 TESTING AND COMMISSIONING ............................................................................................................. 50

5.27 INSTRUCTIONS AND TRAINING OF LOCAL STAFF ............................................................................... 54

5.28 WORKS EXECUTED BY THE EMPLOYER OR BY OTHER CONTRACTORS ......................................... 55

5.29 SEQUENCE OF OPERATIONS AND DELAYS TO OTHER CONTRACTORS .......................................... 55

5.30 CONTRACTOR'S SITE OFFICES, WORKSHOPS, STORAGE AND WORKING AREAS ......................... 55

5.31 USE OF SITE .............................................................................................................................................. 55

5.32 POSSESSION OF SITE .............................................................................................................................. 56

5.33 INTERFERENCE WITH THE WORKS ....................................................................................................... 56

5.34 REJECTED MATERIALS AND DEFECTIVE WORK ................................................................................. 56

5.35 EXISTING WORKS AND SERVICES ......................................................................................................... 56

5.36 OVERHEAD POWER LINES ...................................................................................................................... 57

5.37 EXISTING ACCESS ................................................................................................................................... 57

5.38 EXCAVATION ACROSS ROADS AND TRACKS ...................................................................................... 57

5.39 LIAISON WITH POLICE AND OTHER OFFICIALS .................................................................................... 57

5.40 PRESERVATION OF TREES ..................................................................................................................... 58

5.41 PROTECTION FROM WATER ................................................................................................................... 58

5.42 PROTECTION AGAINST FIRES ................................................................................................................ 58

5.43 WATCHING, FENCING AND LIGHTING .................................................................................................... 58

5.44 WATER AND POWER FOR USE ON THE WORKS ................................................................................... 58

5.45 FUEL SUPPLIES ........................................................................................................................................ 59

5.46 TELEPHONE AND COMMUNICATIONS ................................................................................................... 59

5.47 SANITATION .............................................................................................................................................. 59

5.48 FIRST AID AND MEDICAL SERVICES ...................................................................................................... 59

5.49 INSPECTION BY PROJECT MANAGER DURING DEFECTS LIABILITY PERIOD .................................. 60

5.50 SIGN BOARDS .......................................................................................................................................... 60

SECTION 1 PIPES AND FITTINGS

1.1 GENERAL

SCOPE

This specification refers to pipes and appurtenant fittings for water supply and distribution pipelines.

STANDARDS All pipes and fittings, and waterworks materials shall conform to only one set of similar Standards (such as AWWA/ANSI/ASTM, or ISO/DIN, etc.) throughout the project. The materials shall be compatible and interchangeable with each other without the use of special adapters.

SUBMITTALS

Manufacturer's data shall be submitted for all materials specified in this section. The submittal shall be in accordance with the information below:

a) Submittals shall be submitted to the Project Manager for review and acceptance prior to construction in accordance with the General Conditions

b) Submit manufacturers recommended method for butt-fusing joints. c) The polyethylene pipe manufacturer shall provide certification that stress regression testing

has been performed on the specific product. Certification shall include a stress life curve per ASTM D2837.

d) The manufacturer's certification shall state that the pipe was manufactured from 1 specific resin in compliance with these Specifications. The certificate shall state the specific resin used, its source, and list its compliance to these specifications.

e) Submit certified lab data to verify specified physical properties. Certify that tests are representative of pipe supplied for this project.

f) Submit affidavit of compliance with referenced standards (e.g., AWWA C901, C906, etc.). g) Submit qualification certificates for operators of heat fusion equipment. h) Submit schedule for placement of and removal of test bulkheads.

1.2 MATERIALS MATERIALS TESTING Testing services by independent testing laboratories for manufactured goods shall be appointed by the Owner and test specimens may be selected by the Project Manager either at the place of manufacture or at the job site and shall be delivered to the testing laboratory by the Contractor. The number of pipes and fittings specimens to be tested shall not normally exceed 0.5% of the number of pieces to be supplied to the site. However, where initial testing indicates inadequacies in the materials additional testing may be required.

DELIVERY, STORAGE, AND HANDLING

a) On site pipe storage shall meet all manufacturers' requirements. b) Transport individual pipe lengths to the job site on padded bunks with nylon tie-down straps

or padded bonding to protect the pipe. Coiled HDPE pipe shall be stored in a manner to ensure safety. Protect the pipe from sharp objects. Anchor pipe securely to prevent slippage.

c) Store individual pipe lengths on earth berms or timber cradles in the numerical order of installation. Stack the heaviest series of pipe at the bottom. Do not stack pipe in excess of 20-rows high.

d) Protect the pipe from stones and sharp objects. e) Store fittings in their original cartons. f) Lift pipes with handling beams or wide belt slings near the middle of joints as recommended

by the pipe manufacturer. Do not use cable slings, chains, or hooks. g) Before installation, check pipe and fittings for cuts, scratches, gouges, buckling, kinking, or

splitting. Remove any pipe section containing defects by cutting out the damaged section in a complete cylinder.

PIPE AND FITTINGS FOR SERVICE CONNECTIONS HDPE pipes and fittings shall meet the requirements of BS 3284 and 5114 respectively. They shall be transported, laid, jointed and backfilled in accordance with the manufacturers written instructions. For diameters up to and including 63 mm they can be supplied in coils of up to 100 m long. Coils of diameters greater than 63 mm shall be supplied with each layer bound separately to facilitate safe unwinding. For diameters from 125 mm upwards they shall be supplied in lengths not exceeding 12 m. For pipes of diameter 100mm and less HDPE connectors shall be used. For diameter 125mm and above fusion jointing shall be applied. Installation – including fusion jointing work on HDPE pipelines – must be directed and supervised by suitably qualified and experienced persons and the Contractor shall have demonstrated his ability to provide this in his Tender. All pipe diameters specified are internal diameters.

Pipes, fittings and coils shall be stored in such a way that they are completely protected from direct sunlight. When covered they must be well ventilated to avoid accumulation of heat and resultant deformation. Transparent coverings shall not be used. The storage location shall be flat and shall, for pipes, support the pipes throughout their length. Stones and sharp objects shall not be present. Pipes shall not be stacked to a height exceeding 1 m. The pipes must be secured at the sides to prevent them from rolling. Contact with harmful materials shall be avoided. As far as possible, coils shall be stored in a horizontal position. The area shall be free of stones and sharp objects. If stored upright they must be secured to avoid tilting. NIPPLES AND FLANGED STUB ENDS

Short nipples and stub ends shall be of the same material as the HDPE pipe

FITTINGS

a. Fittings shall be made from material meeting the same requirements as the pipe. Fittings shall be fabricated by the manufacturer of the pipe.

b. Fittings shall meet the appropriate AWWA standard for the size involved (C901 or C906) and shall be Pressure Class 160 for water main and reclaimed water main and Pressure Class 100 for wastewater force main.

c. Molded fittings shall be manufactured in accordance with ASTM D3261 and shall be so marked.

d. Mechanical fittings, when used, shall be specifically designed for, or tested and found to be acceptable for use with HDPE pipe.

e. Fittings used to connect with dissimilar pipe materials shall be provided as per Section 15062 "Ductile Iron Pipe and Fittings."

JOINTS

a. Sections of polyethylene pipe shall be joined into continuous lengths on the job site above ground. The joining method shall be the butt fusion method and shall be performed in strict accordance with the pipe manufacturer's recommendations. The butt fusion equipment used in the joining procedures shall be capable of meeting all conditions recommended by the pipe manufacturer.

b. Butt fusion joining shall result in joint weld strength equal to or greater than the tensile strength of the pipe. Socket fusion shall not be used. Extrusion welding or hot gas welding of HDPE shall not be used. Flanges, unions, grooved-couplers, transition fittings, and some mechanical couplers may be used to connect HDPE pipe mechanically without butt-fusion only where shown in the Drawings.

c. Ductile Iron to HDPE Connections i. Flanged connections between ductile iron pipe or fittings and HDPE pipe or fittings

shall meet all requirements of "Ductile Iron Pipe and Fittings." ii. Mechanical joint connections between ductile iron pipe or fittings and HDPE pipe

or fittings shall use ductile iron mechanical joint glands conforming to AWWA C111 and AWWA C153. Mechanical joints shall be fully thrust restrained. Gaskets, bolts, and hexagonal nuts shall be standard rubber gaskets conforming to AWWA C111. Follower gland shall match class 350 compact fittings.

iii. HDPE pipe stiffeners shall be constructed of stainless steel and shall be flanged on one end to prevent over-insertion into the receiving pipe.

HEAT FUSION

a. Use fusion equipment specially designed for heat fusion of HDPE. The equipment utilized shall be regulated for the different melt strength materials. Compatibility fusion techniques shall be used when polyethylene of different melt indexes are fused together.

b. Use the following procedure to butt fused HDPE pipe. If a procedure noted below contradicts manufacturer's recommendations, follow the manufacturer's recommendation.

i. Maintain the proper temperature of the heater plate as recommended by the pipe manufacturer. Check it with a tempilstik or pyrometer for correct surface temperature.

ii. Clean pipe ends inside and outside with a clean cotton cloth to remove dirt, water, grease, and other foreign materials.

iii. Square (face) the pipe ends using the facing tools on the fusion machine. Remove all burrs, chips, and fillings before joining pipe or fittings.

iv. Check the line-up of pipe ends in the fusion machine to see that pipe ends meet squarely and completely over the entire surface to be fused. The clamps shall be tight so that the pipe does not slip during the fusion process.

v. Insert the clean heater plate between the aligned ends and bring the ends firmly in contact with the plate but do not apply pressure while achieving the melt pattern. Allow the pipe ends to heat and soften. Softening depths shall be per the manufacturer's recommendation.

vi. Carefully move the pipe ends away from the heater plate and remove the plate (if the softened material sticks to the heater plate, discontinue the joint, clean heater plate, square pipe ends, and start over).

vii. The melted ends shall be connected rapidly but not slammed together. Apply enough pressure to form a double rollback bead to the body of the pipe around the

entire circumference of the pipe about 1/8-inch (3.175-mm) to 3/16-inch (4.763-mm) wide. Pressure is necessary to cause the heated material to flow together.

viii. Allow the joint to cool and solidify properly. Remove the pipe from the clamps and inspect the joint appearance.

QUALIFICATION OF FUSION OPERATORS

Each operator performing fusion joining shall be qualified in the use of the manufacturer's recommended fusion procedure(s) by the following:

Appropriate training or experience in the use of the fusion procedure. 1. Making a sample joint according to the procedure that passes the following inspections

and tests: a. The joint shall be visually examined during and after joining and found to have the

same appearance as a photograph or sample of an acceptable joint that was joined in accordance with the procedure; and

b. The joint shall be tested or examined by 1 of the following methods: i. Pressure and tensile test as described in standards ii. Ultrasonic inspection and found to be free of flaws that would cause failure iii. Cut into at least 3 longitudinal straps, each of which is:

1) Visually examined and found to be free of voids or unbonded areas on the cut surface of the joint, and

2) Deformed bending, torque, or impact and if failure occurs, it must not initiate in the joint area.

2. Each operator shall be re-qualified under the procedure if during any 12-month period: a. Operator has not made any joints under the procedure; or b. Operator has 3 joints or 3% of the joints made, whichever is greater, that are found

unacceptable by testing according to the above standards

POLYVINYL CHLORIDE (PVC) PRESSURE PIPE

Polyvinyl Chloride (PVC) Pressure Pipe for service connections shall be for a pressure of 1.0 MPa (PN 10) or as specified in the BOQ or elsewhere in the Contract and shall conform to the requirements for PVC and fittings stated in this section for PVC Pressure Pipe.

PVC pressure pipe shall conform to ISO 161, Wall thickness to ISO 4065, and PVC plastics to ISO R1965. The pipe shall also conform to the following supplementary data:

(a) Unless otherwise stated all pipe shall be rated for a minimum of 1.0 MPa (PN 10) potable cold water service. The wall thickness shall for PN 10 pipe be not less than ISO 4065 pipe series S=10. Where stated the pipe shall be rated for a minimum of 1.6 MPa (PN 16) potable cold water service. The wall thickness shall for PN 16 pipe be not less than ISO 4065 pipe series S=6.3.

(b) If requested by the Project Manager, the supplier shall submit an affidavit of compliance with the standard specifications and supplementary data as required for evaluation.

(c) Joints shall be integral-type bell and spigot, push-on, with a preformed synthetic rubber gasket.

(d) Couplings shall be of a class and strength equivalent to the pipe.

(e) Joints shall be capable of taking a 4 degree minimum deflection per joint.

(f) All pipes shall be of 6 m net laying length unless otherwise specified or approved by the Project Manager except for HDPE pipes, which shall be in rolls of 50-150m long.

(g) A sufficient quantity of lubricant, gaskets and application brushes shall be supplied with the pipe.

(h) All pipe diameters specified are internal diameters.

CAST IRON FITTINGS AND SPECIALS

Cast fittings and specials shall be grey iron or ductile iron with a rated working pressure of 1.0 MPa for pipe of pressure class PN 10, and with a related working pressure of 1.6 MPa for pipe of pressure class PN 16.

Mechanical seal joints on fittings to pipe shall be formed by a bell and preformed rubber gasket suitable for the pipe to which the joint is made.

Flanged joints on fittings shall be flat faced conforming in dimension and drilling to the standards specifications. One Standard shall be used throughout the contract.

FLANGES

Flanges shall be according to ISO 2084 and shall be for pressure greater or equal to that of the pipe. One Standard shall be used throughout the contract.

FLANGE GASKETS

Flange gaskets shall be manufactured from natural rubber and shall be 1.5 mm thick with a layer of cotton on both sides.

BOLTS

Flange bolts shall be stainless steel, machine bolts with square heads. Nuts shall be hexagon. Studs may be used where necessary. Bolt length shall be such that, after the joints are made up, bolts shall protrude through the nut, but not more than 12 mm.

All bolts and nuts shall be stainless steel.

Dissimilar metals shall not be used in pipe joints.

FLEXIBLE COUPLINGS Flexible couplings shall be with ductile iron center sleeve and end rings finished with a corrosion resistant coating, rubber gaskets, stainless steel, bolts and nuts.

The coupling shall be capable of joining plain-end pipes of the same outside diameter, or the same nominal diameter but of varying actual outside diameters, or of different nominal diameters as indicated.

Flanged adapter couplings shall be with ductile iron body and end rings finished with a corrosion resistant coating, rubber gaskets, stainless steel, bolts and nuts. The coupling shall be capable of joining plain-end pipe to standard flanged fittings.

PIPE SADDLES FOR WATER SERVICE CONNECTIONS

Pipe saddles for use on HDPE/PVC pipes shall be as follows for the respective tapping size.

Tap Size Nominal Pipe Size

19 mm - 25 mm 20 mm - 50 mm

32 mm - 50 mm 150 mm - 300 mm

Saddles shall be sized properly for the type and outside diameter of the pipe on which they are installed. Makes and models must be submitted for the prior approval of the Project Manager.

1.3 WORKMANSHIP

HANDLING

The Contractor shall use every precaution to prevent damages to the pipe. Any damage to the pipe from any cause during transport and before final acceptance by the Owner shall be repaired as directed by the Project Manager, by and at the expense of the Contractor. Material that cannot be repaired shall be removed and replaced at the Contractor's expense.

Pipe shall be loaded and unloaded without dropping, by hand or by using side boom tractors or other equipment approved by the Project Manager. The Contractor shall not roll or drop the pipe from any conveyance used for hauling.

Pipe and specials shall be handled using only wide canvas, leather, or rubber-padded slings. Use of bare cables, chains, hooks, pipe clamps, or other similar equipment will not be allowed. The width of belt slings shall be not less than one-half (1/2) the diameter of the pipe being handled.

Extreme care shall be exercised to prevent damage to pipe ends.

The Contractor shall ensure that all joints are made watertight to the satisfaction of the Project Manager. Items to be used for this work shall include hemp, thread tapes, WD-40, pipe jointing compound (Boss White), uPVC Solvent (Targit) among others.

1.4 PAYMENT

MEASUREMENT AND PAYMENT

Payment for the supply and handling of materials referred to in this section to the point of delivery, will be made as shown in the Tender Form of the Contract for the Supply of Pipes and Fittings.

SECTION 2 VALVES, STOPS AND HYDRANTS

2.1 GENERAL

SCOPE

This specification refers to valves, stops and hydrants for water supply and distribution pipelines.

STANDARDS

All pipes, fittings, valves, stops, hydrants and miscellaneous waterworks materials shall conform to only one set of similar standards (such as AWWA\ANSI\ASTM\CSA, or ISI\DIN, etc.) throughout the project. The materials shall be compatible and interchangeable with each other without the use of special adapters.

SUBMITTALS

Manufacturer's data shall be submitted for all materials specified in this section. The submittal shall be in accordance with Section 1.3 of this specification.

2.2 MATERIALS

AIR VALVES

Air valves shall be double orifice type to suit a maximum working pressure of 1.6 MPa and a hydrostatic test pressure of 2.4 MPa. Valves shall have a cast iron body with two chambers, each housing a ball, one chamber having a cast iron small orifice plate with bronze seat, the other having a cast iron large orifice plate with rubber seat. The valves shall be supplied with rubber gaskets and cast iron splash covers.

Double orifice valves shall incorporate the characteristics of both the small orifice and the large orifice valves. The valves shall exhaust small pockets of air when the line is under pressure, fully open the large orifice when the valve chamber is empty and fully close "drop-tight" when the chamber is full of water.

Small orifice (air release) valves shall be float actuated and be open when valve chamber is empty and closed "drop-tight" when the chamber is full of water. Internal levers, pins, screws, etc., shall be stainless steel or bronze.

Large orifice (vacuum breaking) valves shall have a ball sealed orifice, fully open when the valve chamber is empty and closed "drop-tight" when the chamber is full of water.

Surface boxes for air valves shall be of cast iron and suitable for installation in roads and of the following sizes:

(a) For 200 mm diameter air valves, 900 mm x 900 mm clear opening with two piece chained lid.

(b) For 150 mm diameter air valves, 900 x 900 mm clear opening with two piece chained lid.

(c) For 100 mm diameter air valves, 700 mm x 400 mm clear opening with one piece chained lid.

FLAP VALVES

Flap valves shall have cast iron frames and doors with non-ferrous metal facings. They are to be double hung with hinge pins and links of suitable non-ferrous materials.

CHECK VALVES

Check valves 65 mm and smaller shall be bronze, swing check type, with threaded inlet and outlet, Crane Model 37 or as approved.

Check valves 75 mm and larger shall be ductile iron body with stainless steel trim, resilient seating (Buna-N), with stainless steel spring, globe type, with flat face flanges compatible to those specified in Section 30800 and full face gaskets, Apcc Series 600, or as approved.

VALVE BOXES

Valve boxes shall be a sectional, telescoping construction, capable of withstanding surface traffic and impact loading without transmitting such loads to the valve. A top section or surface box shall be complete with a lid, which is secured in place and detectable with metal\magnetic-field locating equipment. A middle section or sleeve pipe shall be suitable for inserting a Valve operating key, have a minimum inside diameter of 100 mm, and a length suitable for the surface box and the required depth of burying the valve plus an adjustment of plus or minus 0.2 m.

Valve boxes shall be fabricated of corrosion resistant material or have corrosion resistant coatings on surfaces in contact with the soil.

Internal extension spindles where required shall be suitable for use with the valve box installed and consist of a bottom socket, rock shield and top-operating nut, and galvanized steel extension rod to suit the length of the valve box.

CORPORATION STOPS

Corporation stops shall be similar to Mueller H-15008 with inlet thread compatible with the pipe saddles specified in section 30837.

Compression joints shall be complete with stainless steel liners for inserting into plastic tubing.

FIRE HYDRANTS

Each hydrant shall be complete with one 90 degree flanged x spigot duck-foot bend, one flange extension (if necessary) for 1 m trench depth, surface box, one standpipe with instantaneous fire-hose couplings, and one operating key.

Hydrants shall be of the underground screw down type with a nominal diameter of 80mm, and shall conform to an internationally accepted standard, coated according to the manufacturer's recommendations.

2.3 SPARE PARTS

The Contractor shall submit in his Technical File detailed parts lists and drawings for all valves and hydrants, including a list of recommended spare parts and prices for each spare part. The Project Manager on the basis of the information submitted will determine the exact type and quantity of spare parts to be supplied.

2.4 WORKMANSHIP

HANDLING

The Contractor shall use every precaution to prevent damage to the materials supplied. Any damage from any cause during transport and before final acceptance by the Owner shall be repaired as directed by the Project Manager, by and at the expense of the Contractor. Materials that cannot be repaired shall be removed and replaced at the Contractor's expense.

Materials shall be loaded and unloaded without dropping, by hand or by using cranes or other equipment approved by the Project Manager. The Contractor shall not roll or drop the materials from any conveyance used for hauling.

2.5 PAYMENT

MEASUREMENT AND PAYMENT Payment for the supply and handling of materials referred to in this section will be made for supply to the point of delivery as shown in the Tender Form of the Contract for the Supply of Pipes and Fittings.

PART 3 – CONCRETE

SECTION 3 – CONCRETE

3.1 SCOPE AND STANDARDS

This Section describes the quality of materials and workmanship of concrete and reinforced concrete works cast in situ in all parts of structures below or above ground. The specification shall apply to concrete prepared on site as well as ready mixed concrete and small precast concrete elements. It is based on BS8110: 1997 in general, and on BS5337: 1976 in respect of exposure of concrete to water and moisture. The standards and Codes of Practice, detailed below are by reference made part of this Specification. BS: Part I Structural use of Concrete

BS 4550 Portland Cement Methods of Sampling & Testing

BS 12 Portland cement (ordinary and rapid hardening)

BS 410 Test sieves

BS 812 Methods for sampling and testing of mineral aggregates, sands and filters

BS 882 Aggregates from natural sources for concrete

BS 1305 Batch type concrete mixers

BS 1370 Low heat Portland cement

BS 1881 Guide to use of non-destructive methods of test for hardened concrete

BS 3148 Tests for water for making concrete

BS 4449 Carbon steel bars for the reinforcement of concrete

BS 4466 Bending dimensions and scheduling of bars for the reinforcement of concrete

BS 4482 Steel wire for the reinforcement of concrete

BS 4483 Steel fabric for the reinforcement of concrete

BS 4550 Methods for testing cement

BS 5075 Concrete admixtures

BS 5135 Metal-arc welding of carbon and carbon manganese steel

BS 8007 Code of practice for the design of concrete structures for retaining aqueous liquids

BS 5606 Code of practice for Accuracy in Building

BS 4027 Sulphate Resisting Portland Cement

BS 8110 Structural use of concrete – parts 1-3

ASTM standard C309 Liquid membrane forming compound for curing concrete

ASTM standard C260 Air entraining admixtures for concrete

In case of discrepancy or contradiction, the requirements of this specification shall rule over any standard.

3.2 CLASSIFICATION OF CONCRETE 3.2.1 Normal Concrete

All normal concrete (i.e., other than mass concrete as specified below) to be used in reinforced and plain structure is classified in the contract documents according to required strength grade as per Table 1 and to (exposure) class as per Table 2. Table 1: Grades of Concrete and Strength Requirements

Grade Characteristic Cube Strength at 28 days, in N/mm2 Strength Work Cube [1] Trial Mix [1] N/mm2 Average Each Individual Average

10 10 12.3 8.5 15 15 20.0 12.8 21.5 20 20 27.5 17.0 31.5 25 25 32.5 21.3 36.5 30 30 37.5 25.5 41.5 40 40 47.5 34.0 51.5 50 50 57.5 42.5 61.5

[1] Note: Concrete may be accepted on the basis of 7 days cube strength, provided the average strength is at least 70% of the required 28 days strength.

Table 2: Minimum Cement Content (kg/m3) required for Classes of Exposure

Reinforced Concrete Plain Concrete Class Max. Max.

Free Free Max. Size of Aggregate, mm Water Max. Size of Aggregate, mm Water 40 20 14 10 Cement 40 20 14 10 Cement Ratio Ratio

E 320 360 390 410 0.45 270 310 330 360 0.50 Severe (290) (330) (350) (370) (240) (280) (300) (320)

F 260 290 320 340 0.55 220 250 280 300 0.60 Moderate (240) (260) (290) (310) (200) (230) (250) (270)

G 220 250 270 290 0.65 200 220 250 270 0.70 Mild (200) (230) (250) (260) (180) (200) (220) (240)

Notes: The minimum cement content may be reduced, as given in brackets when:

1. Trial mixes have verified that a concrete with a maximum free water cement ratio not greater than that given for the particular concrete can be consistently produced and that it is suitable for the conditions of transporting placing and compaction.

2. The max. free water/cement ratio is strictly controlled by a site laboratory.

3.2.2 Cement Content

The cement content shall comply with requirements of Table 2. The actual amount of cement needed for each type of concrete in the various parts of the structures shall be determined by the tests as specified hereinafter, taking into consideration actual site conditions. No change in the unit rates submitted for concrete will be allowed, if the actual quantity of cement used to obtain a specified concrete characteristic strength (grade) is greater than the minimum cement content specified in Table 2.

3.2.3 Concrete Designation Concrete may be named on the Drawings and in the Bills of Quantities as follows: Normal Concrete will be designated by three symbols: the first number stands for grade as to strength (Table 1), the middle letter stands for class of exposure (Table 2), the last figure stands for the maximum size of aggregate. Thus, for example, 20-f-40 designates a concrete having a characteristic strength of 20 N/mm2, class of exposure F, and maximum size of aggregate 40 mm.

3.3 CEMENT 3.3.1 Quality

All cement shall be Portland cement of approved manufacture. Unless otherwise specified, it shall be ordinary Portland cement complying with BS 12. Cement shall be sulphate-resistant Portland cement complying with BS 4027 for the water treatment plant clarifiers and filters. Rapid-hardening Portland cement shall not be used in mass concrete. Low-heat Portland cement complying with BS1370 may be used for mass concrete. A certificate that the consignment complies in all respects with the approved standard shall be forwarded to the Project Manager with each consignment. The Project Manager reserves the right subject the deliveries to independent tests and to reject without question such cement that fails to comply with the specification or fails to produce concrete

of the quality or of the rate of hardening specified. All such rejected cement shall forthwith be removed from the site of the works.

3.3.2 Supply The supply of cement to the site shall be made in whole and original bags, marked with the trade mark of an approved manufacture or in special closed bulk containers manufactured expressly for this purpose. Cement from torn bags or cement which has been split and swept up shall not be used. The Contractor shall inform the Project Manager in writing at least 30 days before first shipments are required, concerning the mill or mills from which the cement is to be acquired and the purchase order number, contract number, or other designation that will identify the cement to be used by the Contractor.

3.3.3 Storage In order that cement may not become unduly aged after delivery, the Contractor shall use cement in the chronological order in which it was delivered on the job. Each shipment shall be stored so that it may readily be distinguished from other shipments. The cement shall be free of lumps and shall be otherwise undamaged when used in concrete. Sacked cement shall be stored in a watertight and weatherproof shed a floor raised at least 150mm from the ground. Stacking cement bags to a height exceeding ten layers will not be permitted. Any cement damage by water or otherwise defective and damage bags of cement will be rejected and shall be removed from the site immediately. Bulk cement shall be stored in weatherproof bins or soils to be approved by the Project Manager. The bin shall be emptied and cleaned at regular intervals as directed by the Project Manager. The use of sacked cement which has been stored for more than three months after delivery will not be permitted, except when it is proved by tests, to the satisfaction of the Project Manager that it complies with the requirements of the Specification.

3.3.4 Contractor’s Responsibility A suitable quantity of approved and certified cement shall always be available on site in order to ensure continuity in case of the rejection of a consignment by Project Manager. If the Contractor has used cement for which no certificate of compliance with the standards was submitted as required in Sub-Clause 31.3.1 above or, where the Project Manager has ordered independent tests, before obtaining results of such tests, and the cement is later found defective in quality, the Project Manager shall have the right to reject that portion of the structure constructed with this cement and the Contractor shall be obliged to dismantle or demolish such

structure and reconstruct it at his own expense and with a cement complying with the requirements.

3.4 WATER

Water for mixing and for curing concrete mortar and grout shall be free from objectionable quantities of silt, organic matter, alkali salts, and other impurities. The source of the water to be used shall be subjected to the Project Manager’s approval. Where tests are required they shall be in accordance with BS 3148.

3.5 AGGREGATES 3.5.1 General

Aggregate for concrete (including for granolithic) shall be coarse aggregate and fine aggregate confirming in all respects to BS 882: 1983. The grading shall be such as to produce a concrete with the specified properties, consistency, and one that will work readily in position without segregation and without the use of an excessive water content and can be readily compacted into a dense impervious mass. Aggregate for concrete shall be furnished by the Contractor from approved sources, provided that they meet the requirements of the above standards. The approval of any sources by the Project Manager shall not be construed as constituting the approval of all materials taken from these sources and the Contractor will be held responsible for the specified quality of all such materials used in the works. Specimen samples of aggregates for concrete shall be submitted to the Project Manager for approval before any order is placed. Such approval will not relieve the Contractor of the responsibility of satisfying himself before placing an order that the aggregate will conform to BS882. All aggregate as delivered to the batching plant, shall have a uniform and stable moisture content. The Contractor shall test all aggregates as ordered by the Project Manager, including tests sulphates and chlorides, and shall provide such facilities as may be necessary for procuring representative test samples. The Contractor shall prepare, for preliminary tests and approval, a representative sample of fine aggregate and of each size of coarse aggregate proposed for use in the works at least 30 days before the aggregates are required for use. The cost of all tests required under this Clause as well as the supply of representative samples shall be spread over the items for concrete work inserted in the Bill of Quantities. During construction, the sizes of the coarse aggregates and grading of the fine aggregates shall be determined at least once for every 100 tonnes supplied, and at least once a week a check shall be made on supplies to ensure that the required grading is being maintained. If any aggregate or sand when so tested does not meet the requirements of the relevant Standard, the

Contractor shall forthwith cease to use that aggregate or sand and shall correct the quality and/or grading of the aggregate or sand without cost to the Employer. If aggregates are bought to the site in separate loads containing aggregate of one size, they shall be stored in such a way as will prevent aggregates of different sizes being mixed together. Aggregates mixed either in transport or on site will be rejected. Unloading shall be done in such a way as to prevent excess segregation as directed by the Project Manager. All aggregates, sand and stone intended for use in the works shall be stored on a concrete floor or a screeded and well drained surface to the approval of the Project Manager to prevent contamination by contact with ground. A stock of aggregates permitting concreting operations for at least 5 days shall be available on the site. All sand and coarse aggregate, when required by BS 882, shall be washed in clean fresh water at no extra cost to the Employer.

31.5.2 Sampling and testing of Fine & Course Aggregate

Sampling and testing of aggregate prior to the development of an aggregate source shall be in accordance with the following:

a Aggregate samples shall be taken in conformance with C.D3.201.

b A minimum of one (1) petrographic analysis for each source of supply shall be made in conformance with BS 812: Part I.

c A minimum of one (1) test for the sulphates (SO3) content of the aggregate for each source of supply shall be made in conformance with BS 1074. The total of the sulphate content of the concrete mix shall not exceed 4% by mass of the cement.

d A minimum of one (1) test for chlorides content of the aggregate for each source of supply shall be made in conformance with BS 812: Part 4. The total chloride ion content shall not exceed the limit specified in BS 882, Table 8, and BS 5337.

e A minimum of one (1) sieve analysis of the fine and coarse aggregate for each source of supply shall be made in conformance with BS 812. The gradation shall comply with BS 812.

f A minimum of one (1) test for shell content for each source of supply shall be made in conformance with BS 812: Part 106. The results shall comply with BS 882 and BS 5337.

g A minimum of one (1) test for the 10% fines value for each source of supply shall be made in conformance with BS 812: Part 3. The results shall comply with BS 882: Table 3.

h A minimum of one (1) test for alkali-aggregate reaction for each source of supply shall be made in conformance with ASTM C289 for siliceous aggregates and ASTM C586 for carbonate aggregates.

i A minimum of one (1) test of absorption for each source of supply shall be made in conformance with BS 812. The result shall be less than 3%.

31.5.3 Fine Aggregate

Fine Aggregate shall consist of hard, dense, durable clean, uncoated fragments of natural sand, crushed stone, or other suitable materials approved by the Project Manager for use with the concrete specified and shall be free from clay, organic material or other deleterious substances. The grading of the fine aggregate shall lie within one of the grading zones shown in Table 2 BS 882. For reinforced concrete the grading of the fine aggregates shall be within either grading zones 1, 2, or 3.

31.5.4 Coarse Aggregate – General Coarse aggregate shall be natural gravel or crushed stone or a mixture of natural gravel and crushed stone and shall consist of hard, dense, durable, clean, uncoated fragments.

31.5.5 Coarse Aggregate for Normal Concrete The grading of coarse aggregate for normal reinforced and plain concrete, when analyzed in accordance with BS 812 shall be within the limits given in Table 1 of BS 882. The nominal maximum sizes of the coarse aggregates are 40 mm or 20 mm. The maximum size of coarse aggregate shall be, in general, as large as possible but in no case larger than: a. One quarter of the minimum thickness of the member, or

b. 6 mm less than the distance between reinforcement bars or than the concrete cover over the reinforcement, provided that the concrete can be placed without difficulty so as to surround all reinforcements thoroughly and to fill the corners of the formwork. If the different sizes of coarse aggregates will be supplied separately, then the grading of the coarse aggregates shall be controlled by obtaining the course aggregate in two sizes for aggregate of 20 mm nominal maximum size and in three sizes for aggregate of 40 mm nominal size.

3.6 ADMIXTURES

3.6.1 General Requirements

Calcium chloride or other admixtures containing chlorides shall not be used. Other admixtures may only be used with the approval of the Project Manager.

All admixtures shall comply with the requirements hereinafter specified. The Contractor shall provide test certificates of an approved laboratory to show that the proposed admixtures comply with all the requirements of this specification and provide acceptable documentary evidence, that the proposed admixtures have been used successfully in major concrete projects. To facilitate approval, the Contractor shall provide the following information:

a) the trade name of the admixture, its source, and the manufacturer’s recommended method

of use;

b) typical dosage rates and possible detrimental effects of under-dosage and over-dosage;

c) whether compounds (such as those containing chloride in any form as an active ingredient) likely to cause corrosion of the reinforcing steel or deterioration of the concrete are present, if so, the chloride content (expressed as chloride ions or as equivalent anhydrous chloride) by mass of admixture;

d) the average expected air content of freshly mixed concrete containing an admixture which causes air to be entrained when used at the manufacturer recommended rate of dosage.

Each consignment of admixture shall be supplied in sealed waterproof containers. A certificate showing that the consignment complies in all respects with this specification shall be forwarded to the Project Manager with each consignment. The Project Manager reserves the right to subject the deliveries to independent tests, and to reject without question and admixture which fails to comply with the specification, or is not compatible with any of the other ingredients of the concrete as shown by preliminary tests with the proposed concrete mixes. All prices for concrete include the admixtures of the types and quantities as specified hereinafter. Different admixtures shall not be allowed to mix prior to charging the mixers, and they shall be added to separate ingredients of each batch. When dispensing systems are used separate dispensers shall be used for each admixture.

3.6.2 Air Entraining Admixtures

If ordered by the Project Manager, an air entraining admixture, complying with the requirements of ASTM C260 shall be used in Tremie or Mass Concrete. The amount of air entraining admixture to be used for entraining the required amount of air shall be determined by preliminary laboratory tests and adjusted in the field to meet the specification requirements. The actual amount of entrained air shall be continuously controlled on site. If the air-entraining admixture is to be used together with another admixture, it shall be proved by preliminary tests that both admixtures are compatible and the concrete has no undesirable properties. Laboratory and field procedures shall be subject to approval by the Project Manager. The Contractor shall provide equipment to permit on-site measurement of the percentage of air entrained in the concrete and the density of concrete. The air-entraining admixture shall be added in the mixer to each batch together with the water.

3.6.3 Water Reducing, Set Retarding Admixture

All mass concrete and concrete in such structures or parts thereof, as will be determined by the Project Manager, shall include an approved water reducing, set retarding admixture complying with BS 5075, thoroughly tested in conjunction with the particular brand of cement used in the given structure. The quantities of the admixture used and the method of use will depend on the composition of the concrete, prevailing temperature, desired setting time, the manufacturer’s instructions and the results of trial tests. The use of any admixture shall require the prior approval of the Project Manager.

3.7 DESIGNED MIXES 3.7.1 General

The Contractor shall fix the grading of the aggregate and proportions of the mix, on condition that he can prove by advance testing that they are suitable, comply with all the requirements of this specification, such as strength, density, impermeability, durability, etc. and that they are workable and can be transported, placed and compacted by the methods and equipment used on the site, without segregation, without the use of excessive water content and that they can be readily compacted into dense impervious mass. He shall supply the Project Manager, at least 14 days before the commencement of casting, with the results of trial mixes, for each class and grade of concrete, for each maximum nominal size aggregates and each consistency required. Three separate batches of concrete shall be made using materials likely to be typical of the proposed supply and preferably under full scale production conditions. If circumstances make this inconvenient, the batches may be mixed in an approved laboratory. Sampling and testing shall be in accordance with BS 1881. The workability of each of the trial batches shall be determined and three cubes made from each batch for test at 28 days. A further three cubes from each batch shall be made for test at 7 days if required. The test results shall contain the following details: a. Cement content

b. Tests of the quality of the aggregates, their contents and grading, and the quality of cement and admixtures used

c. The proposed mix proportions including cement, admixture and water, expressed in kg/m3 or fresh compacted concrete based on saturated surface dry aggregates.

d. The consistency of the fresh concrete, as measured by the slump tests according to BS 1881.

e. The compressive strength of at least 18 standard concrete cubes in compression made from 3 batches of which 9 shall be tested at 7 days and 9 tested 28 days old.

3.7.2 Approval of Mix Proportions Without detracting from the aforesaid, the Project Manager’s prior approval of the proposed mix is to be obtained. This approval will be given based on the results of the above tests and on condition that it can be proved to the Project Manager’s satisfaction that: a. All materials comply with the requirements for quality as demanded, including aggregate sizes

and grading;

b. Cement content complies with requirements of Table 2 (sub-clause 31.2.1);

c. The consistency of the fresh concrete is suitable for the conditions of transport, placing and compaction in the forms as required in the specifications and in accordance with the equipment and systems of work which are intended to be used;

d. The average compressive strength of 9 standard cured cubes at 28 days age shall be equal to or greater that the average strength required for preliminary tests in Table 1;

e. The concrete is impermeable to water for those part of the structures which will be subjected to standing or running water or water under pressure (Classes E, F and M2).

3.7.3 Contractor’s Responsibility In all cases and under all circumstances, the Contractor shall be solely responsible for the quality of the concrete, including its impermeability to water where required in the structure. Approval of mix proportions by the Project Manager shall be binding upon the Contractor as follows: a. To use materials only of the same origin and quality as used in preliminary tests.

b. To use the above mentioned mix proportion without any changes, except for slight changes due to different grading of aggregate within approved limits, and due to different moisture content of aggregates, and climatic conditions, as approved by the Project Manager.

The Contractor may propose alternations in source of supply, mix proportions and gradings of aggregates, provided that he complies with the requirements of the specification, and provided the proposed change does not interfere with the progress of the work. Changes by the Project Manager in proportions or materials, or both, may be made as necessary, without any additional payment to the Contractor, to secure the required properties during progress of work, should it be found impracticable to obtain concrete of required workability, strength, density, and/or impermeability with materials and transporting, handling and compacting equipment approved by the Project Manager and furnished by the Contractor.

3.8 NOMINAL MIXES

On less important concrete structures or elements, the Project Manager may allow the Contractor to use nominal mixes without preliminary trial mixes for ordinary structural concrete of class G exposure under the following conditions:

a. The concrete mixes shall be produced to comply with all requirements of the specification,

including requirements of Tables 1 and 2.

b. The materials comply with all the requirements of the specification.

c. No admixtures are used or required

d. Evidence can be provided to the satisfaction of Project Manager that with the materials and workmanship available in the particular locality a concrete of required standard can readily be obtained.

e. The Project Manager shall be informed of the nature and source of each material to be used and subsequently whenever a change is made.

Table 4 shows the cement contents for the nominal mixes, which together with the total weight of dry aggregate produce approximately one cubic metre of concrete. Depending on specific gravity of the aggregate slight adjustment may be required to the quantity of aggregates to produce this volume of concrete having the required workability, strength and cement content. Where single size coarse aggregates are used, the proportions should be chosen to produce a combined grading within limits of BS 882 for graded coarse aggregate of appropriate size. The actual batch weights should be calculated to suit the size of the mixer from the values of Table 4. Allowance should be made for a moisture content typical of the aggregates being used.

Table 4: Nominal Mixes for Ordinary Structural Concrete

Concrete Nominal Max. Medium Workability High Workability Grade Size of

Aggregate, mm 40 20 14 10 40 20 14 10 Limits to slump that may be expected, mm 50-100 25-75 10-50 10-25 100-150 75-125 50-100 25-50

C-10 Cement, kg 210 240 230 260 Total Agg., kg 1,900 1,850 1,850 1,800 Fine Agg., % 30-45 35-50 40-45 35-50

C-15 Cement, kg 250 280 270 310 Total Agg., kg 1,850 1,800 1,800 1,750 Fine Agg., % 30-45 35-50 30-45 35-50

C-20 Cement, kg 300 320 340 360 320 350 380 410 Total Agg., kg 1,850 1,800 1,750 1,750 1,750 1,750 1,700 1,650 Sand [1] Zone 1 35 40 45 50 40 45 50 55 Zone 2 30 35 40 45 35 40 45 50 Zone 3 30 30 35 40 30 35 40 45

C-25 Cement, kg 340 360 380 400 360 390 420 450 Total Agg., kg 1,800 1,760 1,700 1,700 1,750 1,700 1,650 1,600 Sand [1] Zone 1 35 40 45 50 40 45 50 55 Zone 2 30 35 40 45 35 40 45 50 Zone 3 30 30 35 40 30 35 40 45

[1] Sand is fine aggregate resulting from natural disintegration of rock. Zone numbers refer to BS

882 Table 2.

3.8.1 General Except as otherwise provided hereinafter, the amounts of sand, bulk cement, and each size of coarse aggregate entering each batch of concrete shall be determined by weighing, and the amount of water shall be determined weighing or volumetric measurement. Where sacked cement is used, the amount of cement entering the mixtures shall be determined on the basis of integral sacks of cement of known weight. For concretes of grades 10 and 15, class ‘G’ the Project Manager may, in exceptional cases, permit volumetric measurement of aggregates. The Contractor shall provide equipment and shall maintain and operate the equipment as required to accurately determine and control the amount of each separate ingredient entering the concrete. Moreover, the Contractor shall be able to ensure timely calibration of the compressive test machine from recognized standardizing organization.

3.8.2 Weighing Equipment A separate weighing device shall be provided for the cement. All weighing equipment shall be subject to the Project Manager approval. An accuracy to within 0.5 percent of the scale capacity will be satisfactory, and the equipment shall be capable of ready adjustment to compensate for the varying weight of any moisture contained in the aggregate and to effect changes in concrete mix proportions. The accuracy of the measuring equipment shall be within +/- 3% of the quantity of cement, water and total aggregate being measured, and within +/- 5% of the quantity of any admixture used. The Contractor shall provide standard test weights and any other auxiliary equipment required for checking the operating performance of each scale or other measuring device and shall make periodic tests over the ranges of measurements involved in the batching operations. The tests shall be made in the presence of the Project Manager’s Representative and shall be adequate to prove the accuracy of the measuring devices. Unless otherwise directed, tests of equipment in operation shall be made at least once in two weeks. The Contractor shall make adjustments, repairs, or replacements as may be necessary to meet the specified requirements for accuracy of measurement. The operating mechanism in the water measuring device shall be such that leaking will not occur when the valves are closed. Water tanks on portable mixers shall be constructed so that the indicating device will register, within the specified limits of accuracy, the quantity of water discharge, regardless of the inclination of the

mixer setting. Where the batching plant involves the use of storage bins and weighing hoppers, each weighing unit shall include a visible springless dial which will register the scale load at any stage of the weighing operations from zero to full capacity or shall include an over-and-under indicator which will show the scale in balance with no load or when loaded at any desired beam setting. The weighing hoppers shall be constructed so as to permit the convenient removal of overweigh material in excess of the prescribed tolerances. Each dial or over-and-under indicator and each water-measuring device shall be in full view of the operator.

3.8.3 Batching by Volume Where batching by volume is permitted by the Project Manager (see sub-clause 31.9.1), only precisely dimensioned gauge boxes approved by the Project Manager shall be used for the sand and different sizes of aggregates. After filling the box the aggregate shall be struck-off level with the brim. The mix proportions by volume shall be based on the actual unit weight of the aggregates in measuring boxes including their moisture content. All gauge boxes shall bear marks in red oil paint showing the kind and size of aggregate for which each box is to be used. No boxes similar in shape and appearance but different in volume from the approved gauge boxes shall be kept on the site.

3.9 MIXING

The concrete ingredients shall be mixed in sufficient number of approved batch mixers of adequate capacity complying with BS 1305. The number of mixers employed shall be regulated to suit the requirements of the concrete placing operations. In addition, sufficient reserve capacity shall be available at all times. The concreting capacity of mixers will be subject to the approval of the Project Manager, who will prohibit concreting, should the capacity in his opinion be inadequate. Any mixer that at any time produces unsatisfactory results shall be tested according to BS 1305 and shall be repaired promptly and effectively or shall be replaced. Mixers shall not be loaded in excess of their rated capacity unless specifically authorized. The mixing shall continue until there is a uniform distribution of the materials and the mass is uniform in colour and consistency, but in no case shall the mixing be less than 1 minute for batches of up to 0.50m3 and 1½ minutes for larger batches after all the ingredients, including the full amount of water, are in the mixer. The Project Manager may permit, subject to preliminary tests, to reduce the above mixing times for high-speed pan type mixers by half a minute. The Project Manager shall have right to increase the above minimum mixing time when the charge and mixing operations fail to produce a concrete batch throughout which the ingredients are uniformly distributed and the consistency is uniform. The concrete shall also be uniform from batch to batch, except where changes in composition and consistency are required.

Water shall be added prior to, during and following the mixer-charging operations. Excessive over mixing requiring the addition of water to preserve the required concrete consistency will not be permitted. No dry materials shall be introduced into the mixer until all material from the previous batch has been removed. Incrustations of concrete or mortar shall not be allowed to accumulate on the interior surface of the mixing drum. Re mixing of concrete, or addition of water in an attempt to improve the consistency of a mixture which has already begun to set or which is otherwise unsuitable for casting, shall not be permitted and such concrete shall be wasted. Where small quantities (not exceeding 3 cumecs) are involved, the Project Manager’s Representative may in exceptional cases permit hand mixing of lean and other non-reinforced concrete. No hand mixing shall be done unless authorized in writing by the Project Manager’s Representative. The batches in hand mixing shall not exceed 0.25m3. Hand mixed concrete shall not be used until the mixing of the whole colour and consistency. Hand mixing shall be done twice on dry aggregate, and at least twice wet, on a clean and even surface, which will prevent the loss of water during mixing. The water added shall be measured in order to prevent the use of an excessive quantity water. When mixing by hand, the quantity of cement shall be increased by 10%, above that specified in Table 2.

3.10 TRANSPORTING OF CONCRETE

The methods and equipment used and the speed required for transporting of concrete on site shall be such that concrete having the required composition and consistency will be delivered into the work, without objectionable segregation, loss of slump or delay. No more than 30 minutes shall elapse between the first wetting of all concrete ingredients and composition of placing the concrete in the work.

3.11 READY MIXED CONCRETE

3.11.1 General The use of ready mixed concrete brought to the site from a central off-site batching plant requires the Project Manager’s approval. Approval shall be granted only if the following conditions are fulfilled:

a. The location of the plant permits delivery under normal transport conditions within one hour after batching.

b. Mixers shall conform to approved national standards.

c. The plant has sufficient capacity and transportation equipment to deliver the concrete at the desired rate.

d. The concrete mix will contain set-retarding admixtures at no extra cost if required by the Project Manager.

e. The Project Manager can check at all times the manufacturing process, the quality of the concrete ingredients, the accuracy of the measuring devices, the mixers and all other equipment used.

f. All materials and mixes used comply with all requirements of specification,

Every consignment shall be accompanied by a bill of lading including at least the following information:

a. Concrete Designation

b. Nominal maximum size of coarse aggregate

c. Slump

d. Minimum (or if required maximum) cement content

e. Time of adding water to mix

f. Pumpability, if required

g. Chemical admixtures

h. Maximum permissible addition of water

Retempering (addition of water on site) will not be allowed, except for the amount stated in bill of lading. Concrete which has lost slump and which cannot be returned to the required slump with the amount of water stated above shall not be accepted.

3.11.2 Approval of Mixes from Operating Concrete Plants

The Project Manager may approve standard mixes from operating concrete plants without preliminary trial mixes subject to the following conditions:

a. Existing data as evidence of satisfactory previous performance of proposed mix, including impermeability to water where required.

b. Results of current quality control tests of materials to be used to prove compliance with specifications.

The proposed mixes will be accepted by the Project Manager if they comply:

a. With required minimum cement contents as per Table 2 or 3.

b. With strength requirements of Table 1 or 3.

3.12 CONSISTENCY OF CONCRETE

Uniformity in concrete consistency from batch to batch will be required. The slump as measured according to BS 1881 shall be within the following limits:

± 25 mm or ± 1/3 of the approval value, whichever is greater.

3.13 PREPARATION OF FOUNDATIONS

All earth surface against which concrete is to be placed shall be leveled, wetted and rammed to required lines and grades, the cost of such work being deemed included in rates for earthwork and/or concrete. On the rock surfaces prepared as under Clause 22.6.2, a 15 mm layer of 1:3 cement mortar shall be spread immediately prior to placing concrete and shall be well immediately prior to placing concrete and shall be well worked into the surface with the aid of brushes. Care shall be taken that the mortar does in no case set before concrete is placed on it. The cost of such mortar and its spreading shall be held to be included in the rates for concrete.

3.14 PLACING OF CONCRETE 3.14.1 General

No concrete shall be placed until formwork installation of parts to be embedded and preparation of surfaces involved in the placing have been approved by the Project Manager. All surfaces of forms, reinforcement bars and other embedded materials that have become encrusted with dried mortar or grout from concrete previously placed shall be cleaned of all such mortar or grout before the surrounding or adjacent concrete is placed. Concrete shall be placed only in the presence of the Project Manager or his Representative, unless written permission is given for placing concrete in their absence. The Contractor shall give the Project Manager at least twenty-four hours’ notice of his intention to cast concrete in any structure or major part thereof, stating the exact hour at which concreting is to commence, to enable the Project Manager or his Representative to be present or to grant permission to place concrete in their absence, which permission shall, in such event, not be unreasonably delayed or withheld. Concrete shall be deposited in all cases as nearly as practicable directly in its final position and shall not be caused to flow in a manner to permit or cause segregation.

Excessive separation of coarse aggregate from the concrete caused by allowing the concrete to fall freely from too great a height or at too great an angle from the vertical or to strike the forms of reinforcement steel will not be permitted. Where such separation would otherwise occur, the Contractor shall provide suitable drop chutes and baffles to confine and control the falling concrete. Except as intersected by joints all formed concrete shall be placed in continuous approximately horizontal layers, the depths of which shall be from 30 to 60 cm and in lifts not exceeding 1.80 m in height, unless specified otherwise. The Contractor shall make such arrangements and shall time his operations in such a manner that no layer of concrete will being setting before the neat layer is placed on top of it. In no case shall the delay between the placing of any two layers be such that the vibrating unit will not readily penetrate of its own weight the concrete placed before the delay. Concreting should be carried out continuously between and up to joints, the position and arrangement of which shall be predetermined and approved by the Project Manager in writing. The surface of all concrete during deposition shall be maintained reasonably level between planes of stoppage formed by vertical stopping-off boards or other vertical faces. In the event of unavoidable stoppage in position not predetermined, the concrete shall be terminated on horizontal planes and against vertical surfaces in the manner before described. Where it becomes necessary or desirable, to allow concrete to stand so long that it may set before the work is renewed, keyways shall be formed in the surfaces as shown on the drawings or as directed by the Project Manager. Retempering of concrete will not be permitted. Any concrete which has become so stiff that proper placing cannot be assured shall be wasted. Where the concrete abuts against earth or any other material liable to become loose, the greatest possible care shall be taken by cutting away or otherwise removing, the timber shoring (if any) in small depths and lengths at a time, and otherwise, to avoid falls or runs of such or other materials upon the surface of the concrete. If any such falls or runs occur, the surface of the work soiled thereby shall be removed until a new and clean surface shall have been obtained. All spaces left of such falls or runs beyond the prescribed width of the work, or caused by negligence of or for the convenience of the Contractor, shall be built up with concrete at the discretion of the Project Manager. The additional cost so incurred shall be held to be included in the Contractor’s rates in the Bill of Quantities for work within the original contract limits. Special precautions approved by the Project Manager shall be provided to protect the fresh concrete, immediately after casting, from quick drying and plastic shrinkage cracking and from being washed away due to rain.

3.14.1 Placing Concrete in Wet Ground

Wherever concrete is to be placed in wet ground, shallow drains shall be excavated below the ground formation, filled with broken stone, and connected to suitably placed sumps.

A concrete carpet, the top of which will form the foundation level for the structural concrete, shall then be laid.

3.14.2 Placing Concrete Below Water Level

No Concrete (unless expressly permitted by the Project Manager in writing), shall be placed in or under water. In all cases where concrete is to be placed below water level, the water table level is to be lowered by pumping in such a way that the sub-base shall not be disturbed. The method of lowering the water table shall be subject to approval by the Project Manager. The lowering of the water table shall continue after the concrete has been placed, and permission to stop pumping must be obtained from the Project Manager. During the whole period, standby pumping equipment shall be kept on site. The concrete shall be placed only after the Project Manager has approved the arrangements which have been made for the pumping equipment and the method of ground water lowering. All concrete placed below water level, where expressly permitted by the Project Manager, shall contain additional cement at a rate of 10% above the cement content as defined in Table 2 for class ‘E’ exposure.

3.14.3 Special Requirements

a. Machine Foundations

Machine Foundations shall have all holes for anchor bolts formed in them to the exact requirements of the equipment manufacturer. All such holes shall be accurately positioned by the use of templates supplied by or prepared to the intersections of the plant manufacturer. The machine foundation blocks shall be separated from the adjacent floors and the gaps shall be filled with approved compressible joint filler such as Flexcell or similar.

b. Concrete Floors Concrete Floors supported on grade shall be cast in alternative bays of not more than 2.40 m square and shall be finished as shown on the Drawings or as directed by the Project Manager.

SECTION 4 CONCRETE GROUND LEVEL RESERVOIRS (GLR)

4.1 GENERAL

The Reservoirs shall be constructed of reinforced concrete with all appurtenant pipework for water supply and drainage, metalwork and valve chambers, all as shown on the Drawings and Site Works. The pipe works for the reservoirs shall be performed in accordance with the relevant Works in Section 73.

4.2 SITE WORKS

All site works near and around the reservoirs, such as site formation, access roads, fences and gates, drains, etc., shall be carried out in accordance with the relevant clauses of the Specification.

4.3 EXCAVATION 4.3.1 Ground Level Reservoirs

The Contractor shall excavate to formation levels for the blinding layer under the floors of reservoirs including wall and columns foundations in accordance with Section 22 of the Specification and the excavated material shall be stored for subsequent re-use as backfilling. Excavation of sumps, column footings, pipe blocks and the like shall be performed below the general level of the floor subgrade to the lines and levels shown on the Drawings. The final subgrade on which the blinding layer is to be placed shall be finished to the exact lines and slopes and shall be watered and rammed to obtain a firm base for the blinding concrete in accordance with Clauses 22.9 and 22.10.

4.4 PREPARATION OF GLR FOUNDATIONS 4.4.1 In Excavation

When excavation for the G.L. reservoirs in accordance with Clause 32.3 has reached formation levels, the subgrade shall be prepared by one of the methods specified below depending on the nature of the soil encountered. The Project Manager will in each case decide as to which method of foundation preparation is to be employed, and the Contractor shall request the Project Manager’s decision as soon as excavation has reached formation level. The Contractor shall not proceed with the work unless he has asked for and obtained the Project Manager’s decision.

a) When the subgrade is suitable stable soil, it shall be compacted to an effective depth of 30 cm to a density of 100 percent of the maximum dry density at optimum moisture content as obtained from Test No. 12 described in BS 1377: ( hereinafter “ Standard Proctor Density”).

b) Where the subgrade is in sound rock, no special preparation is required at formation level except for cleaning and draining rock surfaces as specified.

c) Where the subgrade has irregular rock outcrops or is otherwise unsuitable as a reservoir foundation, it shall be excavated to not less than 0.6m below the required grade, unless otherwise shown on the Drawings or instructed by the Project Manager, and backfilled to the proper level with approved compacted granular backfill.

d) The area on which compacted fill is to be placed shall be prepared by watering, harrowing and compacting with the equipment used for compacting earthfill as described above.

No stones having a maximum dimension of more than 50 mm shall be placed in the fill. The material shall be placed in continuous, approximately horizontal layers having a thickness after compaction of not more than 150mm if the material is laterite or clayey sandy soil, and not more than 200mm in the case of sand or gravel.

The material shall be compacted at the optimum moisture content. The moisture content shall be maintained throughout placing and compacting operations.

When each layer of material has been conditioned to the best practicable moisture for compaction purposes, it shall be compacted to the required density by tamping rollers, rubber tired rollers, vibrating rollers, or other approved compacting equipment, according to the nature of the fill material, and no subsequent layers shall be spread until the previous layer has been fully consolidated. The exact type and weight of the roller to be used shall be determined by the Project Manager on the basis of compaction tests made on the materials to be compacted. Final grading of the backfill shall be done in accordance with Clause 32.3

4.4.2 In Fill

Where the designed floor underside is wholly or partly above the natural ground level, the ground surface shall be stripped and if necessary excavated to at least 60 cm below said designed level, and compacted backfill shall be placed in accordance with Sub clause (d) above. Such backfill shall extend beyond the perimeter of the reservoir to be finished with a berm 3 m wide and which shall not be less than 1 m above reservoir floor, and a slope of 1:2.

4.5 BLINDING LAYER 4.5.1 Where required a blinding layer in concrete Class 15-G-10 of a thickness as shown on the Drawings

or as directed by the Project Manager shall be cast on the finished subgrade. The blinding layer shall be levelled with a straight edge to obtain a flat surface to receive the concrete foundations and floors of reservoirs.

4.6 FOUNDATIONS AND FLOORS

Floors, foundation to columns sumps and concrete in surrounds to inlet and outlet pipes below the floors in ground level reservoirs shall be of reinforced concrete Class 30-E-20. Reservoir floors shall first be cast to a truly horizontal surface, which shall be left rough to provide a good bond with the finishing layer. The final slopes of the reservoir floor shall be formed in Class 15-G-10 concrete. The finished floor surface shall be trowelled in accordance with Clause 31.20, with the addition of 1.5kg of cement per square metre of surface.

4.7 WALLS OF R.C. RESERVOIRS

The walls of reservoirs, including the tower of the Elevated Tank, shall be of reinforced concrete Class 30-E- 20 cast in lifts not exceeding 1.80 m in height. Construction joints shall be prepared as specified in Clause 31.18. Absolute water-tightness of such joints is essential. Wrot formwork shall be used on internal and external surfaces. The parts in contact with earth may be cast against unwrot forms. Core holes and recesses shall be formed where shown on the Drawings and where ordered by the Project Manager for ladder stays, cleats and brackets, and grouted or concreted after fixing. Alternatively, subject to permission of the Project Manager, the Contractor may embed anchor plates in walls during concreting and weld on fixing brackets and cleats later.

4.8 COLUMNS

Columns and baffles in the reservoir shall be of reinforced concrete Class 30-E-20. Columns shall have a circular cross sections and shall be cast in one continuous operation integrally with their heads. Care shall be taken to ensure that the columns are truly vertical. Columns shall preferably be cast in one continuous operation with the roof.

4.9 ROOFS

The roofs shall be of flat slab construction with a raised rim cast in concrete Class 30-E-20 and shall have a slight slope from the center towards the rainwater spouts. The roof of the reinforced concrete reservoir shall be separated from the wall top by 2 layers of an approved preformed plastic sheet to provide a sliding joint between roof and wall top and filled with joint sealing compound as specified below (Clause 32.11).

4.10 VALVE AND DRAIN CHAMBERS

Walls of valve chambers shall be of 150mm thick solid concrete blocks, covers shall be of precast concrete class 30-E-20 with C.I. surface boxes.

Drain chambers shall be of reinforced concrete Class 30-E-20. Floors shall be cast on a 50 mm thick blinding layer of concrete class 15-G-10. Covers shall be of precast concrete.

4.11 JOINTS

Joints at the wall footings and column bases shall have rubber or PVC waterstops of approved type and make incorporated in them as shown on the Drawings and in accordance with the requirements of Clause 3.32 Care shall be taken to ensure that the joint surfaces are truly horizontal or vertical and plane and to this end all shuttering shall be rigidly supported and the top surface of the wall footing shall be carefully finished. At the joints between the floor and column bases, the surfaces of concrete members first cast shall be painted with two coats of bitumastic paint to prevent adhesion of the concrete subsequently cast against them. A rectangular caulking groove shall be formed along these joints and filled with joint sealing compound. Prior to placing the reservoir wall, the surface of the wall footing shall be covered with two layers of plastic sheet as specified above for the top of the wall. The vertical groove between the wall and footing shall be filled with an approved compressible performed joint filler and sealed at the top with joint sealing compound. The joint sealing compound shall be of the two-component, poly-sulphide based type, and of approved make. It shall be suitable to withstand tropical climatic conditions without deteriorating. The manufacturer’s instructions as to preparation and cleaning of caulking grooves and mixing and placing of joint sealer shall be strictly adhered to. Sealing compounds of suitable viscosity shall be used on horizontal and vertical surfaces respectively.

4.12 PIPES AND FITTINGS

The Contractor shall install all pipes, valves fittings, and other accessories for the inlet and outlet, drain and overflow pipes, complete as required for the proper operation of the reservoirs, all in accordance with the Drawings and the Project Manager’s instructions. All pipes, valves fittings, etc., as well as the workmanship employed in their installation shall be in accordance with the applicable clauses of the Specification dealing with pipelines, Division 7.

4.13 METALWORK

The Contractor shall supply, build-in, fix and paint all required metalwork as shown on the Drawings, such as ladders, climbing steps, covers and vents on roofs, including fly screens, water level indicators, etc., all in accordance with Section 51 of the Specification.

4.14 DITCHES AND TRENCHES

Pipe trenches shall be excavated to the lines and grades as shown on the Drawings or, as directed by the Project Manager in accordance with Section 72 of the Specification. Overflow ditches with flat bottoms and sides cut to 1.5:1 slopes shall be excavated to the required lines and gradients, from the outlets of the drain and overflow pipes to the nearby natural drain.

4.15 SURFACES IN CONTACT WITH EARTH

The exterior surfaces of concrete of water retaining structures which are to be in contact with earth shall be given two coats of an approved bituminous paint.

4.16 TESTING OF RESERVOIRS

As soon as possible after completion of each reservoir and before backfilling (if any), the Contractor shall clean and remove all dirt from walls, columns and floors and fill the reservoir with clean water to the intended working level.

The structure shall be checked for leakage three days after filling has been completed. At the end of

the period, the exact water level shall be determined by the Project Manager. If after a further period of 14 days the drop in the so determined water level shall not exceed the due

allowance made by the Project Manager for evaporation losses, the structure will be considered watertight and accepted by the Project Manager.

Evaporation losses shall be measured in a separate watertight container suspended in the water in

the tank being tested. Should the drop in the water level exceed evaporation losses, the Project Manager shall carefully examine all external surfaces of the structure, and shall mark all visible wet spots and leaks. Such visible wet spots and leaks shall be kept under the Project Manager’s observation for an additional period of 30 days.

If, after this additional period, leaks are still in existence and/or the drop in the water level exceeds

evaporation losses, the Contractor shall repair and make good all defects by cutting and renewing or otherwise as directed by the Project Manager, without further payment.

No reservoir shall be deemed to have been completed and delivered to or accepted by the Project

Manager until the repairs shall have been proved perfectly watertight to the satisfaction of the Project Manager.

After having been proved watertight on completion of remedial works, reservoirs shall be kept filled

with water until chlorination, where such is required. Lump sum items have been inserted in the Bill of Quantities to cover the Contractor’s expenses for

testing reservoirs. The prices shall include for cleaning and removing dirt, filling with water as many times as may be

required to prove water tightness, and making good all defects and leakages to the satisfaction of the Project Manager.

4.17 DISINFECTION OF RESERVOIRS

Where required, reservoirs shall be disinfected by chlorination. Before disinfection, the reservoirs shall be entirely emptied and perfectly cleaned. All walls are to be scraped to remove all dirt, silt, sand and other impurities. Disinfection will be carried out by painting (preferably spraying) the floor, walls, columns, baffles, ceiling, pipes, etc. with a solution containing 250 ppm chlorine. The solution may be prepared by dissolving calcium chloride (bleaching powder), which shall have an available chlorine content not less than 25%, in water. The actual chlorine content of the bleaching powder shall be ascertained before use. After the solution is prepared, the lime is allowed to settle and the clear water is used for painting the walls.

After a minimum of 6 hours for drying, the reservoir shall be filled with water. Precautions to be taken during painting of the walls include the following:

1) The reservoir is to be continuously ventilated at the time of painting

2) Not less than two workmen shall be in the reservoir while disinfection is being carried out, with a third man outside at the access point into the reservoir.

3) Men working in the reservoir shall wear protective eye goggles and a self-contained breathing apparatus or a face mask combined with a canister containing a suitable absorbent.

4) The men employed in spraying shall wear rain-boots previously sterilized and shall never them outside the structures until the spraying is completed.

4.18 PLACING GRAVEL

Flat reservoir roofs shall be covered with a layer of gravel to a thickness of 10 cm or as shown on Drawings.

The covering of roof slabs with gravel shall be permitted only after a minimum lapse of 14 days after concreting.

No stacking of gravel on the roofs shall be permitted.

SECTION 5 ELECTRICAL AND MECHANICAL WORKS

5.1 SCOPE OF CONTRACT

The Contract shall include the design, manufacture, inspection and works testing, supply and delivery, unloading, supervision of erection, complete installation, commissioning, tests on completion, training of local operators, production of record drawings, installation, operating and maintenance manuals, setting to work of pumping plant, water treatment plant and all associated equipment, pipe work and fittings, electrical equipment and cabling at the Site, finishing, painting and remedying of defects for a period of one year.

The Contractor shall provide sufficient tools and lifting equipment to enable all installation work to be undertaken for completion of the Contract. These said tools should not be used as part of the supply of Special Tools specified elsewhere.

The Contract shall also include the supply of spare parts necessary for undertaking normal maintenance for a period of three years.

The Plant is required to be complete in all respects as specified herein and shall include all items of plant, machinery, fittings, etc., necessary whether such items are specifically referred to in the Contract or not.

The Contractor shall prepare and submit to the Project Manager, in addition to the specified Working Drawings, all details, drawings and technical data required by the Project Manager to enable him to ascertain the foundation requirements, supports and fixings to be built into the Civil Works.

The Contractor shall give all facilities to the Project Manager for inspection and testing, during manufacturing and installation of mechanical and electrical Plant.

The altitude range for the works is between 0 to 500 m.a.s.l.

5.2 DEFINITIONS

In construing the Conditions and the Specification relating to the Plant, the following words and expressions shall have the meanings herein assigned to them unless there is something in the subject matter or context inconsistent with such construction:

"BS" and "BSCP" shall mean the Edition of the relevant British Standard Specification and British Standard Code of Practice respectively current twenty-eight days prior to the date set for the submission of Tenders.

"C.E.E." shall mean the International Commission of Rules for the approval of Electrical Equipment

"IEC" shall mean the International Electro technical Commission "ISO" shall mean the International Organization for Standardization "KPLC" shall mean Kenya Power Distribution Network Company "IEE" shall

mean the Institution of Electrical Project Managers (British)

"Tender Drawing" shall mean a drawing prepared by the Project Manager for Tendering purpose only

"Working Drawing" shall mean a working drawing submitted by the Contractor to the Project Manager for approval, all as specified in the Conditions of Contract

"Contract Drawing" shall mean a drawing, which has been approval by the Project Manager and issued to the Contractor

"Certified Manufacturer's Drawing" shall mean a drawing, which is prepared by the manufacturer, and certified by the manufacturer as showing the exact dimensions and details of the equipment as it will be supplied for the Contract

"Special Tools" shall mean both special tools and appliances necessary for the duties specified

5.3 REGULATION, STANDARDS, MATERIALS AND WORKMANSHIP

All work carried out under this Contract shall comply with the latest requirement of any duly constituted authorities having jurisdiction over the work.

All materials shall comply with the appropriate ISO, British Standard Specification, C.E.E Standards, Kenyan Standard and the recommendations of the IEC as specified. Where an alternative specification to those from such standards and recommendation are to be used, these will be specifically referred to hereinafter.

All references to such standards shall be to the latest edition or revision thereof unless otherwise stated. Where a specific ISO, British or other Standard is referred to in this Specification, other Standard will be acceptable if they ensures an equal or higher quality of material and workmanship than the Standard referred to at no extra cost to the Employer. If the Contractor intends to use such alternative Standard, he shall notify the Project Manager thereof, submitting with his notice two copies (in English), of the proposed Standard and shall not order any material or perform any work unless and until he has obtained the Project Manager's approval of such Standard.

All materials and equipment incorporated in the Works shall be to the approval of the Project Manager.

The names of the manufacturers of materials and equipment proposed for incorporation in the Works together with performance, capacities, certified test reports and other significant information pertaining to the same, submitted for approval to the Project Manager, who shall have power to reject any parts which in his opinion are unsatisfactory or not in compliance with the Specification. Such parts shall be replaced by the Contractor at no extra cost to the Employer.

All materials and equipment shall be the most suitable for the purpose specified and shall be new and of first class quality, free from imperfections and selected for long life and minimum maintenance.

No second-hand materials whatsoever will be acceptable. The Contractor may be required to produce certified invoices.

All articles and materials specified to conform to ISO, British or other standards shall be clearly and indelibly marked with the appropriate standard number specified, except where marking is impractical when the relevant advice/delivery notes shall include the ISO, British or other standard number with which they are to comply.

All set, fixing and wood screws, studs and the like used through the whole of the electrical installations shall be brass or serialized or other material resistant to corrosion.

5.4 DESIGN AND STANDARDIZATION

The Contractor shall be responsible for the design and submission of calculation of all Mechanical and Electrical works specified in respect of capacity, hydraulic consideration, strength, voltage drop, fault levels, protection and discrimination. The Contractor's design shall be subject to the approval of the Project Manager, which approval shall not in any way relieve the Contractor of his obligations under the Contractor. The Works in the Contract shall be designed to facilitate inspection, cleaning and repairs, where continuity of operation is the first consideration. All Plant supplied shall be designed to ensure satisfactory operation under working conditions. All plant containing rotating parts shall be capable of operating at speeds unto the maximum duty specified without vibration or excessive noise.

The plant shall be designed on the basis that all butt welds are made at the manufacturer s work site. Welding shall only be used for fillet welding of loose flanges to make up pipe lengthen.

All motors, fluorescent lighting and other electrical plants shall have a power factor of not less than 0.94 lagging.

Correspondence parties throughout the contract works shall be the Project Manager to prove inter changeability by actual interchanging of the various parts.

Suitable provisions by means of eyebolts or other means are to be provided to facilitate handling of all items with a mass greater than 70kg.

5.5 PACKING TRANSPORT AND STORAGE OF MATERIALS AND PLANT

Before dispatch from the manufacturer's works, the plant and equipment shall be thoroughly cleaned, Protected against damage, deterioration, corrosion and ingress of dirt. The packing shall be suitable for transport by sea and shall withstand prolonged exposure to a hot atmosphere and storage on site.

All packages shall be clearly and conspicuously marked with the contractor's identification mark and the Employer's reference mark. And should be consigned to the Employer c/o the Contractor.

All separate component parts of the Plant shall be identified by metal tags tied by wire and referenced to drawings, installation instructions, packing lists, etc. Details of the referencing system shall be submitted to the Project Manager for approval.

All items shall be adequately protected from damage and deterioration at all times, including the period of storage and erection at the Site.

All wooden cases and support timbers within cases shall be proofed with suitable anti-termite solution. Straw or similar organic materials shall not be used for packing.

5.6 CONTRACT PERIOD AND PROGRAMME

As required by the Conditions of Contract, the Contractor shall provide within the agreed days of the Commencement Date, a fully detailed programme for the completion of the Works. This programme shall be based on Data Schedule, and shall indicate the programmed dates for the commencement and completion of the following:

z Submission of foundation drawings for approval

z Submission of Working Drawings for approval

z Placing orders with Subcontractors for materials, plant and equipment

z Receipt by the Contractor from Subcontractors of ordered plant, materials and

equipment.

z Inspection and Testing by the Project Manager at the manufacturer’s works

z Delivery to Site

z Erection on Site

z Defects and liability period

The above activities shall be scheduled for each individual plant installation. The programme shall also the planned rate of progress for each month.

The programmed dates shall be coordinated with the civil works contractor and the power supply authorities, and shall be subject to approval by the Project Manager.

5.7 TENDER DRAWINGS

The Contractor shall refer to and examine all Tender Drawings appropriate to any part of the Contract, and to provide and co-ordinate all work accordingly.

Positions of Plant, pipe work, cables, columns, outlets, and other items as shown on the Drawings are approximate and the Contractor shall allow for minor adjustments to final positions as may become necessary during installation. It shall be the responsibility of the Contractor to verify dimensions.

Drawings shall, in general, not be scaled off. However, where the Contractor is measuring cable lengths or similar items, he shall determine the appropriate scale of the drawings and measure to suit his own requirements. The lengths, sizes and ratings of all cables shall be submitted for approval.

The Contractor is not at liberty to modify or alter the disposition of items supplied by others from that shown on Tender Drawings. A part from this reservation, the drawings are issued only to give general guidance and any proposed modifications will only be considered providing the general principles are followed.

The Project Manager may supply to the contractor such further drawings as may be necessary for the manufacture, erection, completion and maintenance of the plant and the contractor shall execute. obey and be bound by the same and shall not be entitled to any extra payment in respect of any work shown or directed to be done by such further drawings unless the Project Manager shall have given written instructions for the same.

5.8 WORKING DRAWINGS

The Contractor shall prepare fully dimensioned scale drawings of builder's work arising from the installation of mechanical and /or electrical plants, for approval of the Project Manager.

The Contractor shall give to the Project Manager full particulars of loading, including moments, details of any anti-vibration measures; and dimensions and positions of foundations and plinths and /or fixings necessary for the support and accommodation of all such plant, so that adequate provision may be ensured.

The Contractor must prepare full working drawings of all plant and services for the complete installation. Including cable layouts, diesel plant drawings, and electrical layouts within buildings, road-lighting and floodlighting column locations. All drawings shall be submitted to the Project Manager for approval before any works are commenced. Where possible service reserves shall be established such that a regular approved layout is achieved for all services, these being dimensioned from fixed points within each compound.

Where the items of Plant offered by the Contractor vary in size and/or configuration from that shown on the Tender Drawings, the Contractor shall submit for approval, the proposed layout for his particular Plant. In this regard, the Contractor is not at liberty to effect major alterations to structures, nor major relocations of Plant, but will be expected to arrange his installation within the space provided. All dimensions affecting accommodation of the Plant supplied under this Contract, and points at which services other than those covered under this Contract are Required, shall be clearly indicated on drawings to be submitted to the Project Manager by the Contractor. These drawings shall show such other details of Plant, not given in the Tender or Tender Drawings, as the Project Manager may require for the purpose of preparing detailed drawings for installation of the Plant and for the purpose of making any necessary modifications to the Works being provided under other contracts.

Any proposed deviations from the arrangements shown on the Drawings shall be clearly stated in the Tender, and will only be considered if the above principles are followed. The information under this Clause is required within 8 weeks of the award of the Contract.

The Contractor shall also, in accordance with his approved programme submitted with his Tender, commence to submit before proceeding with manufacturer's working drawings large scale Plant room layouts, ductwork detailed drawings, pipe work and pipe work support and expansion details "certified" fully dimensioned and detailed manufacturer's drawings of Plant including all necessary wiring diagrams detailing connections, current loading in cables and external wiring requirements, schematic diagrams of the electrical control systems etc. These drawings shall show leading dimensions and design sizes of all Plant.

All these drawings shall either be cleared for general acceptance or commented on by the Project Manager for amendment until finally accepted. The accepted drawings shall constitute Contract Drawings and the Plant shall be manufactured to these Contract Drawings in every particular case. The acceptance by the Project Manager of any drawing does not relieve the Contractor of his responsibility under the Contract, and will not commit the Project Manager or make the Project Manager liable for any mistake of the manufacturer or deficiencies in strength of any part or in the

capacity or efficiency of the Plant for carrying out, in accordance with this Specification, the work for which it is designed.

The Contractor shall supply to the Project Manager two copies of all drawings in English, including associated electrical wiring diagrams for comment and four further copies of all accepted Contract Drawings.

5.9 CONTRACT DRAWINGS

Following approval of the Contractor's Drawings by the Project Manager they shall constitute Contract Drawings and the Plant shall be manufactured in accordance with the approved drawings. The acceptance by the Project Manager of any such drawings shall not relieve the Contractor of his responsibility under the Contract and shall not commit the Project Manager nor make the Project Manager liable for any mistakes or the manufacturer's deficiencies in strength or efficiency in operation of any part or item for its specified purpose.

The Project Manager reserves the right to amend or add to the Contract Drawings as may be necessary or expedient as stated.

The Contractor shall keep available on site copies of all drawings on which he shall periodically update the details to facilitate the production of the Record (As Built Drawings) at the completion of the whole of the works.

Two sets of negatives and two sets of paper prints shall be provided by the Contractor after approval of the drawings and supporting information.

5.10 RECORD DRAWINGS (AS-BUILT DRAWINGS)

Record drawings in A1 size shall be prepared and compiled by the Contractor after the Works have been completed and handed over and shall constitute a permanent record of the whole of the Works as finally built and installed. Five copies shall be produced in the form of black lines on a durable translucent film from which paper prints can be taken by others as required (the drawings could be made using acceptable latest A print of the appropriate wiring connection diagram shall be fixed to the inside of the hinged front of each control cabinet, switchboard panel or distribution switchboard. The print shall be protected by non-flammable transparent material. Where insufficient space is available, the print shall be reduced in size. A copy of the print shall also be provided with the Record Drawings and inserted in the Operating and Maintenance Instructions. In addition, block diagrams of the panel components shall also be fixed to the inside front covers so that operators and maintenance personnel are made aware of the function of each component.

5.11 AMBIENT CONDITIONS

All Plant, materials and installation techniques shall be suitable for the climate conditions and altitude prevailing at the Site as mentioned in Section 1.1.

5.12 SCHEDULES OF TECHNICAL INFORMATION

The Contractor shall complete all the Data Schedules of technical information contained in the Tender Documents particularly any departure or deviations from the Specification and names of manufacturer's of supply of the Plant, Should he fail to do so, then the Tender may not receive full consideration, and may be liable to rejection.

5.13 COPIES OF ORDERS

Copies of all orders for all major Plant items, materials and subcontract works placed with suppliers and subcontractors shall be provided in triplicate to the Project Manager. The orders shall give or shall be accompanied by full details of the material, Plant or work ordered.

Copies of all orders shall be provided in the English language or with an English translation where the actual order is placed in any other language.

5.14 STANDARDIZATION

Corresponding parts and units shall be interchangeable wherever possible. Where required by the Project Manager, the contractor shall demonstrate the parts can actually be interchanged.

5.15 FOUNDATIONS AND BUILDING WORKS

In general, all building, structures and foundation upon which plant will be erected will be constructed by the contractor. The Contractor shall plan his work accordingly by:

z Submitting all his foundation requirements within the specified times, and

z Arranging for the supply of all foundation bolts, trench covers kerbs and other cast in

components in advance of the delivery of Plant.

5.16 INSPECTION AND TESTS AT MANUFACTURER'S WORKS

The Employers representative, Project Managers and his duly authorized representative shall have access to the Contractor's premises at all reasonable times to inspect and examine the material and workmanship of the mechanical and electrical components. Place during its manufacture there and if part of the Plant is being manufactured on other premises, the Contractor shall obtain permission for the Project Manager or his duly authorized representative, to inspect as if the Plant was manufactured on the Contractor's own premises. Such inspection, examination or testing, if made, shall not relieve the Contractor from any obligation under the Contract.

Where the Plant is a composite unit of several individual pieces manufactured in different places, it shall be assembled and tested as one complete working unit, at the manufacturer’s works, to the relevant British or other approved, equal standard where applicable.

The Contractor shall submit his proposed programme of tests for the Project Manager's approval three weeks before the commencement of testing.

The Contractor shall give the Project Manager a three weeks’ notice in writing of the date on any the place at which any Plant will be ready for testing as provided in the Contract and the Project Manager shall thereupon at his discretion notify the Contractor of his intention to inspect such part of the Plant and shall then, on giving twenty four hours’ notice in writing to the Contractor, attend at the place so named within seven days of the date by which the Contractor has stated in his notice the said Plant will be ready for testing. The Contractor shall forward to the Project Manager six duly certified copies of the test readings and characteristic performance curves for items such as pumps, fans, etc.

Whether at the premises of the Contractor, or of any subcontractor, the Contractor, except where otherwise specified, shall provide, free of charge, such labour, materials, electricity, fuel, water, stores, apparatus and instruments as may be reasonable demanded, to carry out efficiently such tests of the Plant, in accordance with the Contract, and shall give facilities to the Project Manager, or to his authorized representative, to accomplish such testing. Where inspection or testing is to be carried out for subcontractors’ works, a representative of the Contractor shall be present.

Works tests shall also be carried out such that due consideration is given to the site conditions under which the Plant is required to function. The test certificates shall give all details be given for all tests.

As and when any Plant shall have passed the tests referred to in this clause, the Project Manager shall issue to the Contractor a notification to that effect.

The Contractor shall not pack for shipment any part of the Plant until he has obtained from the Project Manager his written approval to the release of such part for shipment after tests required by the Project Manager in terms of this clause have been completed to his satisfaction.

5.17 ERECTION AND CHECKING OF WORK

The Contractor shall be solely responsible for transport to the Site, handling and transport about the Site and the erection of the Plant. As each part of the Plant is erected, it shall be subject to approval by the Project Manager.

All parts shall be tested on Site as required, notwithstanding the tests carried, by the Project Manager to prove compliance with the Contract irrespective of any tests, which may have been carried out at the manufacturer's works.

5.18 SUPERVISION AND LABOUR

The Contractor shall provide all skilled and unskilled labour for the completion of the works. The Contractor is required to maintain a competent supervising Project Manager and staff on site throughout the erection and instruction periods, and thereafter as may be required during the defects liability period.

5.19 SPECIALIST SUBCONTRACTORS

Where Subcontractors are not nominated, the Contractor shall appoint specialist Subcontractors for any sections of the Works in which he himself has no experiences, recognised and approved operator.

5.20 SPECIAL TOOLS

The Contractor is to provide one complete set of any special tools and appliances necessary for the operation, testing, maintenance and dismantling of the various sections of the Plant whether of a mechanical or electrical nature.

Tools for each different type of equipment shall be new and unused and kept in a wall-mounted strongbox or boxes each fitted with a suitable lock and two keys. Such tools shall be provided for each and every separate location of the Works and shall not be used by the Contractor during the erection of the Plant. The cost of these tools shall be included in the Contractor's Tender. The strongbox is to be clearly marked or labelled with its description. Each tool shall be identified and a list of tools shall be affixed inside the box lid. Racks shall be provided as necessary to separate the various items.

A provision has been made for the Contractor to schedule such tools and appliances in the Data Schedules and for him to price for such tools and appliances as allowed for in the Schedule of Prices.

5.21 INSTALLATION, OPERATING AND MAINTENANCE MANUALS

The Contractor shall supply to the Project Manager illustrated operating and maintenance manuals. The manuals shall be in one or more volumes in order to separate literature from drawings, etc., as necessary.

The manuals shall be in English. They shall include the following information for the operating personnel:

a) Description of all systems installed, including electric lighting and power installation,

electronic installations, mechanical installation, air systems, automatic controls systems, etc. An identification system should be established and shown on drawings and in the manuals.

b) Description of all Plant supplied including manufacturers' leaflets, which are to be

scheduled for easy of reference.

c) Schedule of all Plant supplied, giving duties, electrical loads, etc.,

d) Schedule of all equipment suppliers (and their local agents) including names, addresses, telephone, telex and Fax numbers.

e) Fully detailed instructions for the installation testing and commissioning of all plant, which

will be undertaken by the contractor including detailed schedules of checks to be carried out prior to putting the equipment into operation.

f) The Start-Up Operation and shut down instructions for all equipment and systems,

g) Full maintenance instructions for all equipment including planned maintenance schedules

or charts giving daily, weekly, monthly, quarterly, half yearly and annual maintenance instruction, together with recommended lubricants and spares. This should also include

details of routine maintenance work that will be within the competence of the normal maintenance staff, and notification of maintenance work that will have to be done the manufacturer, his agent or other specialist operator.

h) Spare parts list.

i) Fault finding charts.

j) Record drawings of all systems installed including general arrangements, conduit and

wiring trunking systems, Plant rooms details, air and water systems flow sheets, wiring diagrams, control schematics and valve charts, etc., to a reduced scale.

k) Certified supplier's drawings of all equipment supplied, which are to be scheduled for

easy reference.

l) Copies of performance curves.

A copy of each manual, at least in draft form shall be submitted four weeks before shipping the equipment to which it refers. The draft manual submitted shall include details of all items of plant and equipment unless separate submission of details of particular items is already approved by the Project Manager.

Six copies of each set of manuals shall be issued to the Project Manager before the Plant is shipped.

The final version, modified as necessary to accommodate any changes on site and all test results and certificates as specified, shall be presented as soon as possible thereafter.

Each manual shall be durable and permanently bound within a stiff binder. The cover of each binder shall be finished with a black waterproof and greaseproof material and the title printed in gold block lettering on the front and on the spine.

5.22 SPARE PARTS

The Tender shall submit with his Tender the completed relevant Data Schedule, listing the recommended spare parts and their prices which are considered necessary for the maintenance of the Plant for two years normal operation. When considering the proposed list he must bear in mind the availability of such Plant in Kenya.

A Provisional Sum has been allowed in the Schedule of Prices for the supply of spare parts. The Project Manager shall decide on which of the recommended spare parts shall be supplied. The prices of the spare parts shall be valid for one year from the award of contract, and the Project Manager will give instructions on which spares shall be provided within this period.

The spare parts shall at least include the following items;

Complete set of spare fuses or MCB's as required

Spare coils and contactors for starters

Recommended spares for control systems

Bearing for pumps, motors, etc.

Spare overloads and contacts for starters

Recommended spares for generator sets and control panels

Any other spares recommended by manufacturers of specialized equipment

All spare parts shall be new, unused and strictly interchangeable with the parts for which they are intended to be replacements and shall be treated and packed for long storage under the climatic conditions prevailing at the Site. Each spare part shall be clearly marked or labelled on the outside of its packing with its description and purpose, and when more than one spare is packed in a single case or other container, general description of its containers and other packages shall be marked and numbered in an approved manner for purposes of identification.

All cases, containers or other packages are liable to be opened for such examination as the Project Manager may require and packing shall be designed to facilitate opening and subsequent repacking.

5.23 LABELS AND PLATES

Identification labels of "Traffolyts" or similar approved material engraved black on white unless otherwise agreed, with not less than 5 mm "lino" style letters shall be fixed on or adjacent to

all equipment, valves, controls switches and distribution gear, by means of at least two brass screws or rivets or other approved means.

Danger or warning tables shall be engraved white on red.

Glue, as the only means of attachment is unacceptable.

All labels shall be in English.

The labels shall bear the identification shown on the drawings, such as indication, designation function and, where necessary, phase voltage, current, pressure and temperature.

Plastic adhesive strip labels or adhesive die stamped tapes will not be permitted.

5.24 DUST, INSECT AND VERMIN PROOFING

All Plant, which is affected by ingress of dust, shall be effectively dust proofed.

All Plant shall be vermin proofed, where no protection is afforded in its normal manufactured form, to ensure that no mechanical breakdown shall occur due to interference or damage by vermin. All materials used in construction or for connections shall be resistant to attacks by insects, microbiological life or other local fauna and such materials shall be to the approval of the Project Manager.

Where cables are laid in trenches, the trenches shall be treated with an approved additive to prevent termite activity, or a termite barrier provided.

Where panels or components are sealed, adequate provision shall be made to dissipate heat so those electrical components are not subject to any form of de-aerating resulting from unacceptable temperature rises.

5.25 ALTERNATIVES

The Contractor's main Tender shall comply fully with the Specifications.

The Contractor is however at liberty to include alternative items of Plant, subject to approval by the Project Manager, which do not completely comply with the requirements of the Specifications provided that the requirements of the following two paragraphs are fulfilled.

The Contractor shall submit manufacturer's detailed descriptions of alternatives and he shall draw attention to any aspect of each component, which does not fully comply, with the requirements of this specification. These detailed descriptions, including and departure from the requirements of the Specification may, after approval by the Project Manager, be included among the Contract documents and each item shall be in accordance with the description of it. Approval of a manufacturer's description shall not include approval of any departure from the requirements of the Specification unless the departure is specifically approved by the Project Manager in writing.

Where Plant differs from that specified the tenderer should submit with his Tender drawings showing any amendments of system design necessary to suit the Plant. The Project Manager will either approve these drawings or issue others if he approves the components concerned.

5.26 TESTING AND COMMISSIONING

5.26.1 General As many tests as (where the test has failed) in the opinion of the Project Manager are possible shall be arranged together. Four copies of the Contractor's records of all tests shall be furnished to the Project Manager.

All material which is specified for tests at the Manufacturer's works must satisfactorily pass such tests before being painted or otherwise coated.

All test instruments shall be to approval and shall be calibrated by a competent as may be approved by the Project Manager.

Full witnessed testing and inspections will be carried out on our plant and equipment, including:

All pumps All

motors

Valves, Actuators Penstocks

Standby diesel plant

Chemical dosing plant

Electrical Switchgear and Motor Control Panels

Electrical reticulation and installations

Other items as may be required shall be inspected and tested.

All major items of plant shall be offered for inspection prior to their being dispatched from the manufacturer's or his Subcontractor's works.

The Project Manager shall be entitled at all reasonable times during manufacture to inspect, examine and test on the Contractor's premises the materials, workmanship and performance of all plant to be supplied under the Contract. If the plant or any part thereof is being manufactured at a plant other than the Contractor's he shall obtain for the Project Manager permission to inspect, examine and test such plant as is required. Any such examination, inspection or testing does not relive the Contractor of his obligation under the Contract.

Where the Contract provides for testing on the premises of the Contractor or any subcontractor, the contractor shall provide free of charge all assistance, labour, materials, electricity, fuel, water, stores, apparatus and instruments as may be required and reasonably demanded for carrying out of the tests.

If after inspecting, examining or testing any plant the Project Manager should decide that such plant thereof is defective or not in accordance with the Contract he may reject the said plant or part thereof by giving the Contractor, within a reasonable time, written notice of such a rejection, stating therein the reason for rejection.

5.26.2 Tests at Manufacturers Works

All electrical plant shall be tested at the manufacturer's works in accordance with the requirements of the current relevant British Standards.

In particular the following tests shall be carried out for specific items:

Control Panels and Switchgear

The following tests shall be carried out for each control panel before the panel is dispatched from the manufacturer's works:

Visual inspection Inspection of provisions for cable entries Checking access, type of cable gland, etc. High voltage power frequency pressure test at 2 kV for 1 minute, followed by an insulation test The relays with variable controlled supply to ensure relays close at 85% nominal voltage and hold closed down to 65% nominal voltage Test tripping of relays occurs at 60% nominal voltage Observe any special tests applicable to the installation Injection testing of current transformers for correct polarity and ratio, and protection relays for correct operation. Functional testing including simulation of operation of sequence controls (e.g. level controls, etc.) Checking of time delay settings and protection relay setting Checking of fuses, MCB's and MCCB's etc. for correct type and rating Check inter-locks Any other tests required by the Project Manager or his Representative.

Electric Motors Electric motors having a rating of 11 KW or less shall be tested in accordance with BS 4999 Table 60.3.1.4 column 5 designated "Routine Check". Motors having a rating of more than 11 KW shall be tested in accordance with BS 4999 Table 60.3.1.4 column 3 designated "Basic". All rotational and temperature rise tests shall be performed with the motor set up in normal working position, i.e. either horizontal or vertical in accordance with the particular drive application. Motors shall not be dispatched for works assembly with associated mechanical plant until test certificates have been approved by the Project Manager. Electrical motors rated 11 KW and above shall be tested for vibration in accordance with the principles contained in ISO 3945, and BS 4999 Part 50. As required by the British Standards, the tests shall include, as applicable: Detailed load tests or type tests on each motor to determine temperature rise, efficiency, speed and power factor, at different loads ranging from no-load to 110% of the continues maximum rating of the motor. Open-circuit test Short-circuit or locked-rotor test Voltage or pressure tests Over-speed test Insulation test High voltage and insulation resistance test shall be made when the apparatus are hot. The power and power factor measuring instruments shall be connected in such a position as to allow for all losses in the complete system and not for the motor alone. Pump sets Each pump shall be tested individually with its own motor over its full working range. Each pump shall be run, and tests carried out in accordance with BS 5316 Part 1, or other standards as approved by the Project Manager, to ensure that performance, power absorbed, and efficiency meet the guaranteed characteristics as shown in the Data Schedules. Each pump set shall be tested for efficiency at each head/ quantity/ speed duty/ The pumps shall be tested complete with all shaft bearings, thrust bearings, and directly driven auxiliaries, or where this is impracticable, the Contractor shall state what allowances shall be made for the losses incurred by these items and shall demonstrate the accuracy of these allowances to the satisfaction of the Project Manager. The speed of the pump shall be stated when recording various readings of head/ quantity pertaining to the pump. Head/quantity curves and pump efficiency / quantity curves shall be drawn and may be necessary. In addition, the curve of overall efficiency of the pump set and power absorbed against the quantity shall be drawn. If necessary, the values of motor efficiencies obtained during the motor works tests may be used. The curve produced shall be used to demonstrate that the Plant will be capable of meeting the full range of operating conditions at site.

The pump set shall be free from cavitation and vibration over the whole working range. Pump castings shall be subject to a pressure test of 1.5 times the maximum pressure obtained with the delivery valve closed. The positive suction head shall be considered in determining this pressure. The Contractor shall satisfy the Project Manager as to the mechanical reliability of the plant and its capability of fulfilling the whole of the conditions. The contractor shall detail the type of apparatus available for testing, and the method of measuring pump discharge. He shall satisfy the Project Manager as to the accuracy of the instruments used in the tests and shall, if required, carry out calibration tests. Valves, actuators, and penstocks All parts, which shall be subject to pressure in service, shall be subject to a hydrostatic test to a pressure not less than 1.5 times the maximum possible working pressure. Valves and actuators shall be tested at the "closed valve head" of the pump plus 10% on one side of the valve and zero pressure on the other. The valves shall be operated for two opening and closing cycles under the action of the actuators against the required pressure. Valves without actuators shall be similarly tested to ensure drop tightness. Penstocks shall be subjected to on and off seating tests where applicable. Diesel Generating Sets Each set shall be tested for output and performance in accordance with the requirements of BS 649 and BS 5000 Part 99. Tests shall include all function tests, operation of all safety devices, load tests and temperature tests. Cable and wiring All cable and wiring shall be fully factory tested. A sample of each cable rating/size shall be tested in the presence of the Project Manager, the tests being those required by the British or other National Standards Institution.

5.26.3 Test Certificates

Test certificates and reports shall be submitted in triplicate to the Project Manager within three weeks of works testing of the following equipment: Motors Control Panels and Switchgear Armoured Cables Distribution Boards Motors

Other as may be identified 5.26.4 Tests After erection on Site

All Plant shall pass such tests on site as are required by the Project Manager to prove compliance with the contract independently of any tests which may already have been carried out at the Manufacturer's works. All electrical pressure tests made at the Manufacturer's works shall be

repeated at voltages to be approved by the Project Manager, and all pump performance tests shall be repeated on Site. The Contractor shall prepare all on site test results and certificates for all items as required by the IEE Regulations and relevant British Standards. These certificates and test results shall be provided in triplicate with copies included within the operation and maintenance manuals. The Contractor shall maintain on Site marked up copies of all changes to the installations as they proceed. These changes shall be agreed with the Project Manager on a weekly basis and shall be included on the Record Drawings produced by the Contractor for all installed equipment as specified elsewhere. All skilled labour, supervision, apparatus, electricity, water, fuel and the like for tests, and instruments required for carrying out the tests efficiently will be the responsibility of and at the expense of the Contractor. The accuracy of the instruments shall be demonstrated if required. Tests on completion shall be carried out to ensure that the Plant is complete, has been correctly installed, is reliable in operation under the conditions at site and is able to operate over its whole working range. In addition, the efficiency and performance of the Plant shall be checked as far as possible over the whole works Range and the values obtained will be compared with those obtained during the tests at the Contractor's premises. The Contractor shall include for all tests that may be require by any statutory Authority. On completion, all plant and pipe work systems shall be properly balanced, left in working order and instructions given on the efficient operation and maintenance of the plant to the Project Manager satisfaction. If, in the opinion of the Project Manager, the Plant does not comply with this Specification, the defect shall be remedied at no cost to the Employer.

5.26.5 Continuous Test Period

The Plant shall be tested, under normal operating conditions over a continued period of 14 days. The Plant shall, at the discretion of the Project Manager, be divided into sections for the purpose of these tests but each and every section shall be tested for the full period of 14 days continuous operation. Where sections of Plant form an integral operation the section of the Plant shall be tested together to ensure the correct and proper functioning of the water pumping, storage and flow systems, The Contractor shall arrange to run all Plant before submission for final testing to ensure that the period will not be interrupted for adjustment or breakdown.

5.27 INSTRUCTIONS AND TRAINING OF LOCAL STAFF The Contractor shall allow operator’s access to the Site during the erection and commissioning of the systems as part of their training programme. There shall be in addition to this, a period of three weeks minimum of official instructions and training after the end of the commissioning period and prior to hand over of the complete systems. The Contractor shall make available for the purpose of instruction, competent staff and all information necessary for the effective execution of the training programme. The Contractor must instruct and train the trainees in such a way that the operation, maintenance and if necessary, repairs to the systems can be handled competently by the respective personnel.

5.28 WORKS EXECUTED BY THE EMPLOYER OR BY OTHER CONTRACTORS

The Employer reserves the right to execute, on the Site, works not included under this contract and to employ for this purpose either his own employees or other contractors whose contracts may be either a subcontract under this contract, or an entirely separate contract. The Contractor shall ensure that neither his own operations nor trespass by his employees shall interfere with the operation of the Employer, or his contractors employed on such works and the same obligations shall be imposed on the Employer or other contractors in respect of work being executed under this contract.

5.29 SEQUENCE OF OPERATIONS AND DELAYS TO OTHER CONTRACTORS The Contractor shall be deemed to have included in his pricing of the Tender for costs associated with works carried out outside normal working hours where such works have been necessary to meet the requirements outlined in Section 28 above.

5.30 CONTRACTOR'S SITE OFFICES, WORKSHOPS, STORAGE AND WORKING AREAS

The contractor shall have stated in his tender the additional areas that he requires for his workshops, storage and working areas. The Employer reserves the right to allocate the areas of the land smaller than the Contractor may require. In such cases the Contractor shall make his own arrangements for obtaining the use of the additional areas that he requires. The location of all offices, stores, and the like shall be to the approval of the Project Manager.

5.31 USE OF SITE

The lands and other places outside the site, which are under the control of the Employer, shall not be used except with the approval of the Project Manager. The Contractor shall at any time remove any vehicles, wagon, barge or vessel or any other obstruction under his control that may be required to be moved by the Project Manager for any purpose. The Contractor shall move such obstruction promptly on instruction given. The Contractor shall maintain access for the inspection, operation and maintenance of any of the Employer's plant or works, which lies within the site or elsewhere. The Contractor shall maintain access for the inspection, operation and maintenance of any of the Employer's plant or works, which lies within the site or elsewhere. The Contractor shall not use any portion of the site for any purpose not connected with the works unless the written permission of the Project Manager has been obtained.

Except with written permission of the Project Manager, to be given when necessary for the execution of the Works, the contractor’s employees will not be permitted to enter any of the Employer's buildings or lands or sites under the control of other contractors or the Project Manager.

The Contractor shall warn his employees that any person found within such buildings or sites without authority is liable to be removed from the works in accordance with the Conditions of Contract

5.32 POSSESSION OF SITE The Contractor shall restrict his activities to those areas of the Site adjacent to the work being executed and shall avoid any encroachment upon land outside the areas for which possession has been given. Any trespass or damage or any claim arising from such encroachment shall be the contractor's sole responsibility and he shall hold the Employer indemnified against all claims arising from such trespass or damage.

5.33 INTERFERENCE WITH THE WORKS The contractors shall not interfere in any way with any existing works, whether under the control of the Employer or of a third party, whether or not the position of the works is indicated to the contractor by the Project Manager, except where such interference is specifically described as part of the works, either in the Contract or in an instruction from the Project Manager.

5.34 REJECTED MATERIALS AND DEFECTIVE WORK

Materials or work which, in the opinion of the Project Manager, do not comply with the specification, shall be classified as rejected materials or defective work, and shall be remove from the works and replaced as directed by the Project Manager.

5.35 EXISTING WORKS AND SERVICES

The Contractor shall acquaint himself with the positions of all existing works and services including water mains, sewers, storm water drains, cables for electricity, telephone lines and telephone, electricity and lighting poles before any excavation is commenced. The Contractor will be held responsible for any damage, however caused, in the course of the execution of the works, to the existing works and services. Such existing works and services, where exposed by the execution of the works, shall be properly shored, hung-up and supported to the satisfaction of the Project Manager and of the authority concerned. The Contractor shall exercise special care when refilling trenches or other excavations around such existing works or services and water meters. Stop cock boxes and the like shall not be covered up.

Poles supporting cables and the like adjacent to the works, shall be kept securely in place until the works are completed and shall then be made as safe and permanent as before. Notwithstanding the foregoing requirements and without lessening the Contractor's responsibility, the Contractor shall inform the Project Manager immediately any existing works have been exposed and shall comply with any requirements of the authority concerned.

Only when and as directed by the Project Manager shall the contractor change the position of existing works or services to meet the requirements of the proposed work.

The Contractor shall make adequate provision so that when carrying out his work, no interference, damage, or pollution is caused to highways and footpaths, or to any mains, drains, sewers, and the like or other parts of the works. Wherever loads have to be carried over the ground in which pipes, valves, culverts, and the like are buried, the contractor shall take all precautions including where necessary the provision and use of sleepered road, light gauge railways or other means to prevent damage occurring to such underground works. The Contractor shall not store any plant or materials or spoil heaps over existing water services, or in such positions that interference with access to the services is created. Approval by the Project Manager of the means of protection employed shall not relieve the contractor of any responsibility in respect of damage occasioned by his operations. The laying of pipework, ducts, drains, and the like shall be arranged so as to cause as little interference as possible with the smooth operation of existing works. When breaking out and making good existing structures the contractor shall disturb the existing structures as little as possible. All structures shall be made good with the materials similar to those used in existing works, or such materials which are considered by the Project Manager to be of similar appearance and suitable in all other respects.

5.36 OVERHEAD POWER LINES

Where work is being carried out in the vicinity of overhead power lines, the Contractor is responsible for ensuring that all persons working in such areas are aware of the relatively large distance that high voltage electricity can "short" to earth when cranes or other large masses of steel are in the vicinity of power lines. The Contractor's attention is drawn to BS 7354:1990, BS 5486-1:1977, IEC 60439:1973, which gives safe clearances for the various voltages. The Contractor shall take all necessary precautions to ensure the safety of his employees and all other persons where work is being carried out in the vicinity of overhead power lines.

5.37 EXISTING ACCESS

Existing access to lands property and all other places shall be maintained by the contractor during the continuance of the Works to the Project Manager's satisfaction.

5.38 EXCAVATION ACROSS ROADS AND TRACKS Before excavating across any public or private road or track, the contractor shall give the Project Manager 10 days’ notice of his intention to excavate and shall include, in writing, the precautions he proposes to take for continuance of passage and traffic, and details of the warning signs and lights to be provided and operated. The excavation shall not commence until the written approval of the Project Manager has been given.

5.39 LIAISON WITH POLICE AND OTHER OFFICIALS

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The Contractor shall keep in close contact with the police and other officials in the area concerned regarding their requirements for the control of workmen, movement of traffic, or other matters and shall provide all assistance and facilities which may be required by such officials in the execution of their duties.

5.40 PRESERVATION OF TREES

No tree shall be removed without prior written permission of the Project Manager who will limit the removal of trees to the minimum necessary to accommodate the permanent works. If trees are removed or damaged by the contractors or his employees, without approval then the contractor shall replace such trees.

5.41 PROTECTION FROM WATER

The Contractor shall keep the whole of the works free from water and shall be deemed to have included for all pumping, sorting, temporary drains, sumps and other measures and provisions

necessary for such purposes and clearing away and making good to the satisfaction to the Project Manager any damage caused thereby.

5.42 PROTECTION AGAINST FIRES

The Contractor is advised that, at all times, it is necessary to guard against fires starting within the site or in the environs thereof, particularly as the result of the works or from the actions of his employees. The Contractor shall have available, at all times, adequate fire-fighting equipment such as safety gears and shall deal with all fires on the Site howsoever caused.

5.43 WATCHING, FENCING AND LIGHTING

The Contractor shall employ competent watchmen and guard the works both by day and night. Any excavations, material dumps, spoil dumps or other obstructions likely to cause injury to any person or thing shall be suitably fenced off and adequately marked and identified.

5.44 WATER AND POWER FOR USE ON THE WORKS

The Contractor shall be solely responsible for the location, procurement and maintenance of a water supply adequate in quality to meet his obligations under the contract. The Contractor may purchaser water for normal and reasonable use on the works from the Employer when and where available and at current rates.

The Contractor shall be solely responsible for the location and continuity of the supply adequate in quality to meet his obligations under the Contract. The contractor may purchase water for normal

and reasonable use on the works from the Employer when and where available and at current rates.

The contractor shall be solely responsible for the location and continuity of the supply of water for use on the works. Supplies may be derived from boreholes, rivers and streams, but shall in all cases be to the Project Manager's approval, and the abstraction of water from any sources shall not interfere with permanent water supply. The Contractor shall be solely responsible for the transporting of water from its sources to the point at which it is required for construction purposes, and in such quantities and quality as to enable the works to proceed without hindrance due to the shortage to adequate water supplies.

The Contractor shall take care to avoid unnecessary use of water and to prevent any water running to waste.

The Contractor shall make his own arrangements for power supplies and shall be solely responsible for the location, procurement and maintenance of a power supply, adequate to meet his obligations under the Contract, nor, in respect of any such failure, shall the contractor have any claim under the contract against the Employer.

5.45 FUEL SUPPLIES

The Contractor shall arrange for obtaining, storing and distributing all fuel oils required for the completion of the Works.

5.46 TELEPHONE AND COMMUNICATIONS

The Contractor shall be responsible for obtaining a suitable means of communication between all sites and compounds for the duration of the contract. This is particularly relevant during the testing, commissioning, and fourteen-day continuous operation of the plant where communications between sites and compounds must be established before the commencement of the testing and commissioning programme.

5.47 SANITATION

The Contractor shall provide adequate sanitation and refuse collection and disposal facilities complying with the laws and local by-laws for all houses, offices, workshops, and the like erected on the site, all to the satisfaction of the Project Manager.

The toiled facilities provided at the Site by the Civil Works contractor may be made available, to the employees of the contractor supplying and installing the mechanical and electrical plant. However, it is the responsibility of contractor to make his own arrangements.

The Contractor shall warn his employees and Subcontractors that any employee found fouling the Site shall be remove from the site immediately in accordance with the conditions of contract.

5.48 FIRST AID AND MEDICAL SERVICES

The contractor shall provide and maintain all equipment necessary to render first aid in case of accidents, snake bites or other emergencies. This equipment shall be kept in readiness at the Works, at camps and wherever the Contractor's staff may regularly live and work. The Contractor shall ensure that there are persons available at all such places with knowledge of simple first aid procedures and able to administer snake bite treatment.

5.49 INSPECTION BY PROJECT MANAGER DURING DEFECTS LIABILITY PERIOD

The Project Manager will give the Contractor due notice of his intention to carry out any inspection during the Defects Liability Period. The Contractor shall, upon receipt of such notice, arrange for a responsible representative to be present at the times and dates name by the Project Manager. This representative shall render all necessary assistance and shall take note of all matters and things to which attention is directed by the Project Manager.

5.50 SIGN BOARDS

The Contractor shall provide a signboard at each site or compound. However, before the erection of any signboards or posters by the contractor, the contractor shall obtain the approval of the Project Manager to the size, location and wording of such signboards and posters.

SPECIFICATIONS - Kericho County · iii. Square (face) the pipe ends using the facing tools on the...

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Transcript of SPECIFICATIONS - Kericho County · iii. Square (face) the pipe ends using the facing tools on the...