Under water concrete

Its used mainly where concrete comes in contact with water while pouring, 10% cement is incresed in under water concrete. W/c of concrete is max 0.6. Concrete shall contain 10 percent more cement than that required for the same mix placed in the dry to compensate the loss due to wash.
Concrete shall not be placed in water having a temperature below 5oC. The temperature of the concrete, when deposited, shall not be less than 16oC, nor more than 40oC.

As tremie method of concreting is not under water concreting, there is no need to add 10 percent extra cement.

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