particular specifications (road works) - CIDCO Maharashtra Ltd.

CIDCO OF MAHARASHTRA LTD
C.A.No.01/CIDCO/SE(KHR)/EE(KHR-I)/2010–11 Pg. No. 352
in advance details of such designs to the Engineer-in-charge for his
prior approval. All the cement concrete of grade M-15 and higher
strength shall be carried out as controlled concrete only and shall be
done with proper mix design. The mix design shall be got approved
from the Engineer-in-charge from time to time whenever there is source
and type of cement and aggregates and change in the gradation of
aggregates.
5.7.1 For Concrete of Grade M-15, M-20, M-25, M-30 :
Preliminary mix design must be carried out from laboratory.
5.7.1.1 The minimum size of aggregate permissible shall be as per IS : 383-
1970 & IS : 456-2000 and in latest amendments, if any.
5.7.1.2 No extra payment over and above the accepted tender rate shall be
made or as reduction in the accepted tender shall be effected in case of
variation in the construction of cement concrete because of the mix
designs or change in the mix design from the standard requirements
for equivalent nominal mix.
5.7.1.3 All the expenses of preliminary mix design, subsequent field laboratory
mix design, work tests shall be borne by the contractor.
5.7.1.4 If the average strength of concrete cube falls below the required
strength, fresh preliminary mixes for that grade shall be made as
before/ Until the trial mixes yield cubes of compressive strength at 28
days greater than the required average strength at the age i.e. fck + 4
N/mm2 as per I.S. 456-2000.
5.7.1.5 Whenever there is a significant change in the quality of any of the
ingredients for concrete, the Engineer may at his discretion order to
carrying out of fresh trail mixes. All costs for trial mixes and tests shall
be to contractor’s account and held to be included in the contract rates.