Time-dependent cyclic behavior of reinforced concrete bridge columns under chlorides-induced corrosion and rebars buckling

This study presents the results of a refined numerical investigation meant at understanding the time-dependent cyclic behavior of reinforced concrete (RC) bridge columns under chlorides-induced corrosion. The chloride ingress in the cross-section of the bridge column is simulated, taking into account the effects of temperature, humidity, aging, and corrosion-induced cover cracking. Once the partial differential equations governing such multiphysics problem are solved through the finite-element method, the loss of reinforcement steel bars cross-section is calculated based on the estimated corrosion current density. The nonlinear cyclic response of the RC bridge column under corrosion is, thus, determined by discretizing its cross-sections into several unidirectional fibers. In particular, the nonlinear modeling of the corroded longitudinal rebars exploits a novel proposal for the estimation of the ultimate strain in tension and also accounts for buckling under compression. A parametric numerical study is finally conducted for a real case study to unfold the role of corrosion pattern and buckling mode of the longitudinal rebars on the time variation of capacity and ductility of RC bridge columns.