Admixtures

Waterproofing admixture is a type of admixture which prevents the passage of water through hardened concrete under a pressure head. It is also called as water resisting admixture or permeability reducing admixture or damp proofing admixture.

Chemical admixtures are the ingredients in concrete other than portland cement, water, and aggregate that are added to the mix immediately before or during mixing.

The mechanism of water resisting admixtures is to reduce the porosity of concrete. To reduce the porosity of concrete, the water content or the water cement ratio must be reduced. Admixtures are used to give special properties to fresh or hardened concrete.