When do we have to start and stop curing concrete?

Sbanary

Apprentice
Start curing after 24 hrs of pouring
Stop : Every Batch of Mix 6 concrete cylinder will be taken to laboratory for Compression Test.

7 days, 14 days and 21 days
2cylinder, 2cylinder 2 cylinder

Suppose you pour concrete of 3000 psi to stop the curing you need to achieve 70% of the strength of the concrete.

First crush test after 7 days.. If you achieve the strength you can stop curing after 7 days. If first set of cylinder failed to achieved the test then

Second set of cylinders will be crushed on 14 days.. If the test failed

Then third set of concrete on 21st day will be crushed if the test passed then you can stop the curing.

But if 3rd set of concrete failed then Your poured concrete will be rejected..

7 days = 2 cylinder (70% of concrete strength 3000 psi (2100 psi)
14 days
21 days

I hope you got your answer..
 

Dnyan Deshmukh

Staff member
Normally curing should be started immediately once the concrete is initially set which generally occurs around after 2 to 3 hours of production of concrete.

As the construction keeps on going contentiously it is always not possible to cure the concrete for longer time till 28 days.

but we should cure concrete for minimum;
in case if concrete is produced with only OPC cement - it can be cured for minimum 7 days.
In case concrete is produced with OPC cement and GGBS - it should be cured for minimum 10 to 12 days.
in case of concrete is produced with OPC cement and flyash - it should be cured for minimum 14 days.

If the conditions allows you to cure it for 28 days, its well and good. If not then, you should ensure above minimum curing period for concrete.
 

Sbanary

Apprentice
Normally curing should be started immediately once the concrete is initially set which generally occurs around after 2 to 3 hours of production of concrete.

Yes sir absolutly right depends upon climatic condition and usually within 24 hrs.. As far as Formwork intact moisture inside the foundation intact.. Yes I agree if surface area of open area is more than no doubt.. Like concrete slab I agree