Axial Compression Behavior of Pre‐Damaged SRC Short Columns Subjected to Chloride Salt Corrosion

Abstract

To investigate the axial compression performance of pre‐damaged steel‐reinforced concrete (SRC) columns under chloride corrosion, this study first analyzed the material degradation mechanism of steel and concrete. Pre‐damage tests were then conducted on 10 SRC short column specimens to examine the effects of key design parameters on their mechanical properties. The results show that the compressive strength of concrete initially increases and then decreases with longer erosion durations or higher chloride concentrations. The yield strength of both profile steel and rebars decreases, with the most significant reduction observed at a chloride concentration of 3.5%. Under axial compression, the profile steel, longitudinal rebars, and stirrups of the columns yield sequentially, while the axial bearing capacity and energy dissipation capacity of the columns exhibit a trend of first increasing and then decreasing. Compared to the uncorroded specimens, after 180 days of chloride salt erosion at a concentration of 3.5%, the axial bearing capacity and ductility of the columns increase by 9.94% and 10.26%, respectively. However, when the erosion period is extended to 300 days and the chloride salt concentration is raised to 5%, these values decrease by 4.72% and 7.88%, respectively, relative to the 180‐day condition. Additionally, higher pre‐damage levels lead to lower bearing capacity and ductility coefficients in the columns. Based on these findings, COMSOL was employed to simulate chloride ion transport in the pre‐damaged columns, revealing the chloride‐induced deterioration mechanism. Finally, a modified model for predicting the axial bearing capacity of SRC short columns was developed by incorporating material corrosion effects based on the design code. The proposed model provides a useful reference for evaluating the axial bearing capacity of SRC columns exposed to chloride environments.