Basis for Determining Minimum Cover Requirement for Durability
Appears on pages(s):
carbonation; chlorides; concrete durability; corrosion; cover; diffusion; permeability; reinforced concrete; reinforcing steels; Design
Based on the present state of knowledge regarding the time to initiation of corrosion, the paper describes a procedure for rationally determining the minimum concrete cover required to protect reinforcing steel against corrosion. The paper uses data that have become available from recent research and literature. It addresses the main factors involved in the initiation phase of the corrosion mechanism: carbonation and chloride diffusion. It also addresses the factor of water penetration into concrete because presence of moisture is necessary for the corrosion process to continue. The procedure presented in the paper can be used to derive minimum cover requirements for corrosion protection on steel in concrete cured for various periods and subject to various exposure conditions.