B-1 AGREEMENT System Generated e-Tender No ... - e-Tendering

75 Dy. Executive Engineer
ADDITONAL SPECIFICATIONS
The contractor shall achieve that following requirements in respect of quantity of work and his contract
rate shall provided for the same.
1.1 ADMIXTURES :
Whenever necessary the admixture should be used to achieved the required workability. The
type of admixture should be got approved from Engineer-in-charge. The rate is inclusive of all
admixtures etc. if found necessary.
1.2 CEMENT CONCRETE IN CONCRETE :
For this purpose the conditions mentioned in additional specifications shall be applicable.
1.3 WATER / CEMENT RATIO :
For high quality concrete of low permeability, the water/cement ratio shall be as per I.S:456-
2000 and mix design.
1.4 CURING FOR CONCRETE :
Special attention shall be paid to curing of concrete in order to ensure maximum durability
and no minimize cracking. Concrete shall be cured with fresh water whenever it is possible to
ensure that the concrete surface can be kept wet despite wind, etc. care shall be taken on
avoid rapid lowering of concrete temperatures caused by applying cold water to hot concrete
surface (thermal shock) Sea water shall not be used for curing reinforced concrete or
prestressed concrete. Where there is doubt about the ability to keep concrete surface
permanently wet for the whole of the curing period heavy duty membranes curing compound
shall be used.
1.5 CONCRETE COVER TO REINFORCEMENT :
(i)
(ii)
(iii)
(iv)
The cover concrete must be of the same quality, impermeability and strength as the
rest of the concrete. Special mix design should be carried out for the concrete to be
used for making concrete cover blocks.
The concrete cover must develop sufficient alkalinity, and protect the steel. The
alkalinity developed shall not be less than 0.04 N and shall not more than 0.08 N.
The cover must be uniform throughout and it's thickness shall be exclusive of plaster
or other decorative finishes.
The concrete cover shall be as per the relevant clause of IS codes. In the case of
poles the cover thickness shall be separately decided by the Engineer in charge.
1.6 DETAILING OF MISCELLANEOUS ITEM :
Binding Wires : All ends of binding wires shall be carefully turned inwards so that they do not
project out of concrete and start rusting action. Plastic coated galvanised wires shall be used.
Wherever possible polythene binding string and polythene bar grips shall be used, after
making sure that these do not result in loss of bond or chemical reaction with concrete. The
use is subject to approval of Engineer-in-charge.
1.7 BAR SPACING : As per relevant I.S. codes and as detailed design drawing or as directed by
Engineer-in-charge.
1.8 HOLLOWS IN CONCRETE : After concreting is complete the concrete surface articularly
where there is congestion of reinforcement, shall be tested by light hammering or if possible
by Schmidtz hammer. Any portion showing signs of hollowness should be grouted
immediately.
Signature of Contractor No. Of Corrections Executive Engineer