Effect of reinforcement corrosion and axial load levels on seismic response of non‐ductile reinforced concrete columns

The present study investigated the seismic response of nonseismically designed reinforced concrete (NSRC) columns affected by varying degrees of reinforcement corrosion and subjected to different axial compression ratios (ACR). 3D numerical models representing corroded and noncorroded field-scale NSRC columns were developed and validated with experimental results. Subsequently, a parametric study was carried out to quantify the combined effect of different ACRs (0.35P0, 0.5P0, 0.6P0, and 0.7P0) and corrosion degrees (0%, 15%, and 30%) on the seismic response of NSRC columns. Critical parameters such as stiffness degradation, hysteresis backbones, ductility ratios, and energy dissipation were evaluated and compared for all the specimens. Results showed that the specimen corresponding to 15% corrosion and 0.7P0 ACR experienced a loss of flexural strength, ductility, and energy dissipation by alarming 55.2%, 60.6%, and 91.3%, respectively. The losses were even higher for specimens subjected to a 30% corrosion level. The quantification of catastrophic performance degradation in corrosion-affected NSRC columns provides crucial insights for designing effective retrofitting strategies to enhance their seismic resilience.