Study on seismic behavior of corroded reinforced concrete walls in flexural-shear failure

In this study, artificial climate-accelerated corrosion tests and pseudostatic loading tests were conducted on six reinforced concrete (RC) shear walls subjected to flexural-shear failure. The effects of the corrosion degree and axial compression ratio parameters on the seismic performance of RC shear walls were investigated. The corrosion conditions (corrosive cracks and corroded steel bars), failure process, bearing ability, deformation capacity and energy consumption capacity were compared. The test results showed that chlorine salt erosion induced severe deterioration of the properties of the RC shear wall. The internal reinforcement of the specimen was severely corroded near the protective layer. The failure mode of the severely corroded specimens changed from the original flexural-shear failure mode to the bending failure mode. Rebar corrosion markedly decreased the bearing ability, deformability and energy dissipation capability of the specimens. Based on the limited test data in this study, the existing equations for calculating the parameters of the characteristic points were modified, and equations for calculating the parameters of the skeleton curve of the corroded RC shear wall were proposed. The cyclic corrosion degradation index was utilized to define the degradation of various mechanical properties of the specimen (yield load, hardening stiffness, reloading stiffness, peak load, unloading stiffness, etc.). With cyclic loading, and considering the pinching characteristics, a restoring force model of a corroded RC shear wall was established based on the Ibarra-Medina-Krawinkler (IMK) model. The comparison illustrated that the built restoring force model was in good agreement with the skeleton curve and hysteresis rules and could accurately reflect the hysteresis performance of corroded RC shear walls to a certain extent.