NECESIDAD DE UNA COORDINACIÓN ENTRE MODOS DE TRANSPORTE

MEASURING : The quantify of cement shall be determined by weight ordinary/ Pozolana Portland cement shall be taken to weight 144 kg./cu.m. (90 lbs per cu..ft.) and rapid hardening Portland cement to weigh 121 kg./cu.m. (80 lbs per cu.ft.). The quantities of fine and course aggregates shall be determined either by volume or preferably by weight. The proportion given is based on the assumption that the aggregates are dry. If the aggregates are not, due allowance shall be made for bulking.

Mixing : Concrete shall normally be mixed in a mechanical mixer. Mixing shall be continued until there is a uniform distribution of the materials and the mass is uniform in colour and consistency but in no case shall mixing is permitted by the Engineer-in-charge. It shall be carried out on a water tight platform and care shall be taken to ensure that mixing is continued until the mass is uniform in colour and consistency.

Transporting : Concrete shall be handled from the place of mixing to the place of final deposit as rapidly as practicable by methods which will prevent the segregation or loss of the ingredients before being placed.

During hot or cold weather concrete shall be transported in deep containers. The deep containers on account of their lower ratio of surface area to mass reduce the rate of loss of water, by evaporation during hot weather and loss of heat during cold weather.

PLACING AND COMPACTING GENERAL : The concrete hall be placed and compacted before setting commences and should not be subsequently disturbed. Methods of placing should be such as to preclude segregation.

CONSTRUCTION JOINTS : Concrete shall be carried out continuously up to construction joints the position and arrangements of which shall be pre-determined by designer.

When the work has to be resumed on a surface which has hardened such surface shall be roughened. It shall then be swept clean thoroughly wetted and covered with a 13 mm (or ½’’) layer of mortar shall be freshly mixed and placed immediately before the placing of the concrete.

Where the concrete has not fully hardened. All laitance shall be removed by scrubbing the wet surface with aware and bristle brushes, care being taken to avoid dislodgment of particles of aggregate. The surface shall be thoroughly wetted and all free water removed. The surface shall then be coated with neat cement grout. The first layer of the concrete to be placed on this surface shall not exceed 15 cm. (or 6’’) in thickness and shall be well rammed against old work, particular attention being paid to corners and close spots.

COMPACTING AND MECHANICAL VIBRATION : All concrete work shall be compacted by Mechanical Vibrators only. Tamping by Iron rods will not be permitted.

FORM WORK OR CENTERING : All form work shall be steel supported and the use of wooden props (Bally) will not be permitted.

FORM WORK CLADDING : contractor will make use of M.S. plates or plywood sheets as cladding to obtain form finish concrete surface.

WATERTIGHTNESS OF CONCRETE : All concrete slabs, beams and water tanks shall be watertight. Contractor shall be responsible for the water tightness of the concrete structures.

NOTES :

1 All concrete and steel conforming to IS 456-2000 and IS 800-1984.

2 All precautions for smooth outside finish and dense concrete will be taken in executing the work.

3 Strength of concrete is the criteria and not the mixes.

4 Minimum cement contains as per IS for consideration of durability.

5 All joints are rigid and water proof shuttering to be provided so that no honey combing will be there.

6 Disturbance of reinforcement of green concrete should not be permitted so as to avoid cracks in green concrete.

7 All steel in reinforcement except 6mm dia. will be Fe 415 (TMT) whereas 6mm dia. will be Fe250.

8 Workmanship and steel centering as per best practice specified by IS code. 9 No laps are permitted near central section or supports.

10 Not more than 50% of steel to have over laps at same sections.

11 Removal of formwork for cantilever portion if any to start for free end after concrete has become effective on support.

12 Material, size and grading as per best practice.

13 Drawing to be read in accordance with architectural drawings in case of discrepancy refers to architect or structural designer.

Contractor Director

(Format of affidavit to be given on Rs. 500/- Non-Judicial Stamp Paper) AFFIDAVIT

I...Age...years, address ... (Authorised signatory to sign the contract), hereby submit, vide this affidavit in truth, that I am the owner of the contracting firm .../authority signatory and I am submitting the documents in envelope no. 1 for the purpose of scrutiny of the contract.

(Name of Work: ...

...). I hereby agree to the conditions mentioned below :- 1. I am liable for action under Indian Penal Code for submission of any false/ fraudulent paper /information submitted in envelope No. 1. 2. I am liable for action under Indian Penal Code if during contract period and defect liability period, any false information, false bill of purchases supporting proof of purchase, proof of testing submitted by my staff, subletting company or by myself. I will be liable for action under Indian Penal Code. 3. I am liable for action under Indian Penal Code if any papers are found false /fraudulent during contract period and even after the completion of contract (finalisation of final bill). Signature of Authorised person Applicant/ Contractor Name ...

Place: ... Date :- Address ... ... E-mail ... Mobile ... Website ...

DECLARATION

I here declare that I have made myself thoroughly conversant with the local conditions regarding all materials such as stones, murum, sand etc. and labour on which I have based my rates for this work. The specifications and lead for this work have been carefully studied and understood by me before submitting the tender. I undertake to use only the best materials approved by the Dean (P&F) /Associate Dean /Engineer-in-charge of the work or his duly authorised representative before starting the work and to abide by his decision.

I hereby undertake to pay the labourers engaged on the work as per Minimum Wages Act, 1948 applicable to the Zone concerned.

Contractors Signature