Stress-strain model for confined concrete in rectangular columns with corroded transverse reinforcement

Reinforcement corrosion and the configuration of transverse reinforcement have evident influences on the stress-strain relation of confined concrete in rectangular corroded columns, which are not properly considered by current stress-strain models. In this paper, the experimental results of 27 reinforced concrete (RC) rectangular columns with corroded transverse reinforcement were discussed, which revealed that key variables such as corrosion degrees have significant influences on the maximum stress and the corresponding axial strain of specimens. Based on test data and nonlinear regression analyses, empirical equations were proposed to account for the impacts of both reinforcement corrosion and the rectangular shape of transverse reinforcement on three important characteristic parameters of the stress-strain curves, namely the maximum strength, the axial strain at maximum strength and the ultimate strain of confined concrete. Comparisons revealed that the proposed stress-strain model outperformed existing models and demonstrated good agreement with test results.