JOB EXECUTION GUIDELINES TECHNICAL SPECIFICATION
TECHNICAL SPECIFICATIONS-MATERIALS
GENERAL :
a. All materials to be used in the execution of Civil & structural works shall be governed by the requirements of this specification.
b. Whenever any reference to IS codes is made, the same shall be taken as the latest revision (with all amendments issued thereto) as on the date of submission of the bid.
c. Apart from the IS codes mentioned in particular in various clauses of this specification, for a specific work under consideration all other relevant codes regarding quality, testing and/or inspection procedures shall be applicable. Reference to some of the codes in the various clauses of this specification does not limit or restrict the scope of applicability of other referred or relevant codes.
d. In case of any variation/contradiction in provisions between IS codes and this specification, the provisions given in this specification shall be followed with the approval of the Engineer In Charge/consultant/architect.
e. All materials shall be of standard quality and shall be procured from renowned sources/manufacturers approved by the EIC /Architect/Consultant. It shall be the responsibility of the contractor, to get all materials approved prior to procurement and placement of order.
f. Quality and acceptability of materials not covered under this specification shall be governed by the relevant IS codes. In case IS code is not available for the particular material, other codes e.g. BS or ASTM shall be considered. The decision of the Engineer In Charge/ consultant/ architect in this regard shall be final and binding on the contractor.
g. Whenever asked for, the contractor shall submit representative samples of materials to the client for inspection and approval. Approval of any sample does not necessarily exempt the contractor from submitting necessary test reports for the approved material, as per the specification / relevant IS codes.
h. The contractor shall submit manufacturer’s test reports on quality and suitability of any material procured from them and their recommendation on storage, application, workmanship etc. for the intended use. Submission of manufacturer’s test reports does not restrict the client/consultant from asking for fresh test results from an approved laboratory of the actual material supplied from any approved manufacturer/source at any stage of execution of work.
i. All costs relating to or arising out of carrying out the tests and submission of test reports and or samples to the client/consultant for approval during the entire tenure of the work shall be borne by the contractor and included in the quoted rates.
j. Materials for approval shall be separately stored and marked, as directed by the client/consultant and shall not be used in the works till these are approved. The contractor at his own cost shall immediately remove all rejected materials from the site.
K. In the event that state, city or other Government bodies have requirements, more stringent than those set forth in this specification, such requirements shall be considered part of this specification and shall supersede this specification where ever applicable.
L. The quality of materials , method and control of manufacture and transportation of all concrete works irrespective of the mix , whether reinforced or otherwise, shall conform to the applicable portion of this specification.
M. Engineer shall have the right to inspect the source/s of material/s , the layout of operations of procurement and storage of materials. Such an inspection shall be arranged and appval of Engineer-In-Charge shall be obtained prior to starting of concrete work.
N. Concrete shall be mixed by mechanical mixer only and no hand mixing shall be allowed for CC works.
NOTE : In case of any contradiction between description of item given in the bill of quantities ( BOQ) and that given in the technical specification , the former i.e. BOQ shall be followed.
EARTHWORK:
1.SETTING OUT AND MAKING PROFILE:
Masonry pillars will be erected at suitable points. These bench mark shall be connected to standard bench mark. In addition to these pillar center line pillars shall also be erected by the Contractor and footing positions shall be marked with the help of these pillars. The necessary profile shall be set out. The level shall be taken at a interval as directed by IEC.
The levels shall be recorded in field books and plotted on plan before starting the excavation.
2. EXCAVATION FOR FOUNDATION:
The cutting shall be done to minimum depths as per drawings and as advised by EIC. Any excess excavation carried out by the Contractor without proper permission from EIC shall not be paid and the excess depth shall be made good by the Contractor by PCC 1:4:8 at contractor’s own cost.
BACKFILLING:
In case water is encountered during the excavation for foundation, or flooding of pits due to any other reasons the contractor shall arrange for dewatering the same at his own cost.
2.1 EXCAVATION IN HARD ROCK:
CUTTING
Where hard rock is met, generally excavation by chiseling and wedging shall be carried out. Excavation by blasting shall be done only after taking all safety precautions and approvals as required and after obtaining written approvals from Engg.-in-Charge/Architects. In case of excavation by blasting all the provisions of explosive rules 1940 (Corrected upto date) shall be complied with storing, transportation and handling of explosive materials. The blasting operation shall be carried out under the supervision of a responsible authorised agent of the contractor. Blasting work shall not be carried out within 200 metres of an existing structure unless otherwise permitted by the Engg.-in-Charge / Architects.
3.0.0 MATERIALS FOR FILLING
3.1.0 SAND
15.1.1 Sand used for filling shall be clean river sand hard, gritty, dry and coarse, free from earth, silt organic matter, clay and other deleterious materials.
3.2.0 MOORUM
3.2.1 QUALITY OF MOORUM:
The moorum shall be naturally occuring material formed by disintegration of rock. It shall be free from vegetarian, rubbish or material of organic origin and scales deleterious to concrete and reinforced concrete.
Pieces of hard rock which do not get crushed under the roller shall not exceed 50mm size.
3.2.2 FILLING:
Filling shall be done in 15 cm thick layers and every layer shall be power rolled with 8/10 ton roller so as to achieve maximum compaction and till such time that no further movement is observed under the wheels of the roller. Hand rolling is permissible in case filling is done inside sales building.
After filling is completed the modified procter density shall be 92% with OMC.
Before start of work the contractor shall supply the samples of murrum from each quarry to cover the variations expected in the supply. The samples shall be tested for the following in a recognised laboratory in accordance with IS:2720 for the following.
Silt and clay content.
Moisture-content and dry density relationship at modified Procter density.
Moisture Control: Water shall be always sprayed and not poured. Ponding shal never be allowed. In wet weather the work may have to be carried out by using suitable safeguards without any extra cost. Care shall be taken to see that moisture is uniformly spread throughout the layer and where necessary mixing with harrows and rakes shall be done.
Measurements: Measurements shall be of the cubic contents of the completed filing and shall be determined by taking level of testing ground and after final layer for each type of filing. All dimensions are for compacted thickness.
4.0.0 CEMENT
Unless otherwise specified ordinary Portland cement of 43 grade conforming to IS:8112 shall be used for all concrete works.However OPC grade 53 may be used after approval of EIC.
4.1.0 SUPPLY :
Cement used shall be one of the following with prior approval of the Engineer In Charge/ consultant / architect.
a. Grade 33 Ordinary Portland cement conforming to IS:269
b. Grade 43 Ordinary Portland Cement conforming to IS:8112.
c. Grade 53 Ordinary Portland Cement conforming to IS:12269.
Portland Slag Cement conforming to IS:455.
Portland Pozzolana Cement conforming to IS:1489.
Cement to be used shall be of the best quality from reputed brands like ACC/ Birla/Gujrat Ambuja/L&T /Lafarge /Grasim or any other equivalent as approved by the Client / consultant.
Where specified, special cement like Sulphate resisting Portland cement (conforming to IS:8042-E), Coloured cement shall be used.
Rapid hardening cement shall have strength in one day equal to that of OPC in 3 days. It shall be used for products like Hume pipe, tiles, sleepers, poles, pre stressed and precast members. It shall also be used for foundation, bridges, culverts, causeways, etc. where quick construction activity is required however with prior permission of the consultant/architect. Test certificates showing that the cement complies with the specifications must be submitted to the EIC /consultant.
Sulphate resistant cement should possess low heat of hydration, more compressive strength at 3, 7 and 28 days than OPC. It should be capable of withstanding attack of aggressive substances like sulphate of sodium, magnesium, calcium, etc. which damage concrete structures. It shall be used with prior approval for structures in or near sea water, where the soil conditions are aggressive, where repeated cycles of drying and wetting occur and also for structures exposed to sulphate attack like industrial drains, sewage pipes, foundations, bridges, dams, tunnels. Test certificates showing that the cement complies with the specifications must be submitted to the EIC/consultant.
Coloured cement shall be white or grey Portland cement mixed with pigment as specified in the item of work. It shall comply with physical requirements of IS:269/8112 and pigments shall be inorganic oxide pigments either natural or synthetic in origin complying with the requirements of B.S.:1014. The pigments used for coloured cements shall be of approved quality and its quantity shall not exceed 10% of cement used in the mix. The mixture of pigment and cement shall be properly ground to have a uniform colour and shade. The pigments shall have such properties as to provide durability under exposure to sunlight and weather. The pigment shall have the property such that it is neither affected by the cement nor detrimental to it.
In case more than one type of cement is used in any work, a record shall be kept showing the location and type of cement used. Each type of cement shall preferably be obtained from one constant source throughout the contract. Cement of different types shall not be mixed with one another. Different brands of cement or the same brand of cement from different sources shall not be used without prior notification or approval by client.
The cement shall be supplied to the site in original sealed bags, which shall be labelled with the weight, name of manufacturer, date of manufacture, brand and type. Cement received in torn bags shall not be used. Bags of cement that vary in weight by more than 3% shall not be accepted.
The contractor shall maintain a daily record of cement received and consumed in an approved form and a copy shall be submitted to the engineer-in-charge once a week.
4.2.0 Storage :
4.2.1 Cement bags shall be stored dry, leak proof, moisture proof and well-ventilated godowns built at the cost of the contractor. Cement of different types shall be stored in separate godowns or separate compartments of a godown.
The floor of the godown shall be raised and shall consist of wooden planks resting on the base prepared with dry bricks laid on edges. Stacking of cement bags shall have a clearance 150 to 200 mm above the floor and 450 mm from the wall.
Cement shall be stored in stacks, which are not higher than 10 bags to avoid lumping due to pressure and in such a manner as to permit easy access for inspection and identification.
The bags shall be kept close together in rows of two bags to reduce circulation of air as much as possible. The bags shall be arranged in header and stretcher fashion so as to lessen the danger of topping.
1.2.5 ‘First in’, ‘First out’ rules shall be applied while removing the bags for use.
1.2.6 Cement stored during monsoons or for an unusually long period, shall be completely enclosed in polythene sheet which shall cover the top of the stack. The contractor shall ensure that the polythene sheet is not damaged at any time during use. Storage under tarpaulins shall not be permitted.
1.27 No stored cement bag shall be used after three months from the date of manufacture. Generally, stacking and storing of cement shall be in accordance with Clause 3.2 of IS:4082.
4.3.0 Quality of cement.
1.3.1 The manufacturer shall satisfy himself that the cement conforms to the relevant Indian standards and if required, shall furnish a certificate to this effect to the purchaser or his representative within ten days of the despatch of the cement.
1.3.2 The contractor shall be fully responsible for the quality of cement brought to work site. In case the contractor has any doubt regarding the quality of cement brought to work site, it is upto him to have it tested at his own expense and make sure that the cement is of acceptable quality.
4.4.0 Testing :
14.1 The contractor shall submit test certificates furnished by the manufacturer to client/consult. Where the client/consultant is not convinced about the quality of cement, he can ask the contractor to have the cement tested or he can take samples in the presence of contractor from cement bags stored at work site and forward them to government approved laboratory for testing. Expenses towards such tests shall be borne by the contractor.