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RESULTS FOR CONCRETE CORROSION

Definition: deterioration of a material, usually a metal, that results from a chemical reaction with its environment.- ACI Concrete Terminology


Corrosion occurs when the protective layer in concrete steel reinforcement is destroyed. Steel in concrete is usually protected against corrosion by the high pH of the surrounding portland-cement paste. Cement paste has a minimum pH of 12.5, and steel will not corrode at that pH. If the pH is lowered (for example, to pH 10 or less), corrosion may occur if moisture, oxygen, and chloride ions are present. Chloride ions destroy the protective layer on the steel reinforcement, making it prone to corrosion. The corrosion product (rust) occupies a greater volume than the steel and exerts destructive stresses on the surrounding concrete.