The process of watering of concrete during construction of a building is called Curing. It ensures to maintain an adequate temperature of concrete in its initial stages, as this directly affects the rate of hydration of cement and eventually the strength of cement and mortar.
Cement has a high heat of hydration, i.e. large amount of heat is released due to the exothermic chemical reaction between cement and water. To prevent the formation of air voids and shrinkage cracks in concrete due to the heat released, water is added periodically and abundantly to concrete. If concrete is allowed to dry out completely, its strength is roughly 40% of the strength achieved by concrete cured properly for 180 days. Also, inadequate curing leads to weak and dusty surfaces having a poor abrasion resistance.
The table shows effect of duration of curing on strength of concrete.