Behavior of corrosion damaged circular reinforced concrete columns under cyclic loading

This paper presents the results of an investigation on degradation of seismic performance of reinforced concrete (RC) columns damaged by reinforcement corrosion. A total of 13 reinforced concrete circular columns were tested under combined cyclic lateral displacement excursions and constant axial load after being subjected to accelerated corrosion tests. The controlled variables in the test were corrosion level and axial load ratio. The steel corrosion loss ratios ranged from 0% to 15.1%, and the axial load ratios varied from 0.15 to 0.9. Based on the test results, degradation models for loading capacity, stiffness, ductility and energy dissipation capacity of columns were proposed. Test results show that higher corrosion levels and higher axial loads result in less stable hysteretic loops with more severe strength and stiffness degradations and worse ductility, and that the energy dissipation of corroded specimens at the same displacement excursions is approximately the same as that of control specimens, regardless of the corrosion level, when the rebar corrosion loss ratio is less than 14%.