Mechanical Properties and Bond Behavior of Corroded Bars

Corrosion is a primary cause of premature deterioration in reinforced concrete (RC) structures, significantly affecting the mechanical performance of reinforcing steel and its bond with concrete. This study examines the effects of corrosion on reinforcing bars, focusing on changes in microstructure, chemical composition, and cross-sectional geometry. The influence of pitting corrosion on yield strength, ultimate strength, and ultimate strain, together with the effect of uniform corrosion on bond stress–slip behavior, is evaluated through a review of empirical models derived from experimental data and validated using nonlinear finite element simulations. The results indicate that deterioration of corroded reinforcement is governed not only by cross-sectional loss but also by microstructural variability and localized mechanisms such as hydrogen embrittlement. Pitting corrosion is shown to be primarily controlled by pit depth rather than total mass loss, while strain distribution becomes highly nonlinear. Furthermore, empirical models tend to overestimate bond strength, as corrosion-induced cracking leads to bond-splitting failure and loss of cover confinement.