Age of Concrete:

Strength of concrete also increases along with the age of concrete because with time the degree of hydration increases and strength is proportional to the degree of hydration. However, the rate of increase in concrete strength decreases along with time, as at later stage the hydration process becomes slower. One can verify this effect on the concrete strength by the fact that for Ordinary Portland Cement almost 90% of the total strength is achieved within 28 days, and about 65% and 40% of 28 days' strength is achieved in 7 and 3 days, correspondingly.