Curing of Concrete:

The procedure of hardening the concrete mixes through keeping its surface moist for a certain period after compaction and finishing is called curing of concrete.

Curing is one of the important factors for obtaining better strength. The concrete hardens because of the chemical reaction between water and cement, i.e. hydration. The chemical action that accompanies the setting of concrete is dependent on the presence of water. While there is enough water at the time of mixing yet it is necessary to ensure that the water is retained to enable the chemical action to continue till the concrete is fully hardened. Properties of concrete such as strength, durability, and wear resistance, water-tightness and volume stability improve with the passage of time. Three gallons of water are required approximately to hydrate one bag of cement. If the loss due to evaporation is more from newly placed concrete, the hydration procedure will stop and concrete will shrink thus creating tensile stresses at the drying surface. An establishment of these stresses will result into the formation of plastic shrinkage cracks.