Modelling effects of corrosion on cover cracking and bond in reinforced concrete

Abstract

Reinforcing bar corrosion leads to a reduction in steel cross-section, cover cracking and deterioration of the steel–concrete bond. A simple analytical model is proposed to demonstrate the consequences of corrosion product buildup around the bars. Critical attack penetration depth of reinforcing bar at the time of cover cracking is calculated. The corrosion pressure due to expansive action of corrosion products before and after corrosion cracking is also estimated. Further bar confinement reduction, change at the steel–concrete interface as well as rib deterioration of the deformed bars are considered in calculating the mechanical interactions between reinforcing bar and concrete. As a result, the bond strength of corroded bars is obtained. Then the load capacity of corroded reinforced concrete beams, designed to fail in bond, is calculated. Reasonably good agreement between experimental results and theoretical analyses is obtained.