Acid Alkali Reaction IS 456

Its also called alkali silica reaction. Alkalise are contained in aggregates. Appearance of Hexagonal type cracks can indicate acid alkali reaction in concrete. It occurs between 10 - 38 degree Celsius temp. cracks can be 0.1 to 10 mm width.
Aggregates should alkali free. Alkali in cement should be less than 0.6 % . It can controlled by use of PPC, non reactive aggregates and control of temp , voids in concrete.

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