Why curing of concrete is done:
Actually we know that reaction b/w cement and water is called hydration , and its an exothermic reaction which releases ( heat) so after adding water to concrete mix than its start hydration process, which makes concrete dry due to out an exothermic reaction which release the heart from concrete mix. there for we curing concrete to to keep it moist.
When to start curing of concrete ?
we have to apply the water for some days on the concrete surface after its setting.
What is the curing period of concrete?
The minimum period for curing concrete to attain maximum strength is 28 Days.
see the below image for period of concrete
in above graph can clear us the concrete can get 50% strength when we cured the concrete for 3 to 7 days, and its gain 75% compressive strength after 14 days and 90% strength can achieve after 28 days.
we cured concrete for the purpose of given factors
we cured concrete due to its chemical reaction between cement and water.
To make good size and shape of concrete member
For atmospheric temperature
For grade of concrete.
To specify the strength of concrete.
Concrete Curing Methods
we can use the given method to keep the concrete moist.
1: Ponding method:
this method we can use in floor slab. we use in this method small pond on slab to keep the slab moist.
.2: Wet Covering
This method is suitable for those concrete structures where we can not make pond but we use this method specially for Column,footing and bottom surface of slabs.and we use to gunny bags to keep the concrete moist.