What is curing of concrete and why is it necessary?

Curing is the process of maintaining adequate moisture and temperature in concrete for proper hydration and strength development. It is essential because hydration requires water - if concrete dries out prematurely, hydration stops and concrete becomes weak, porous, and prone to cracking. Common curing methods include water ponding, wet coverings, curing compounds, and membrane curing. Standard curing period is 7-28 days depending on cement type and conditions.