EXPERIMENTAL AND THEORETICAL STUDIES ON AXIAL COMPRESSION CAPACITY OF RECTANGULAR COLUMNS WITH CORRODED STIRRUPS

In order to investigate the influence of stirrup corrosion on axial compression properties of reinforced concrete rectangular columns, 27 specimens were designed and tested. The variables include cross-sectional shapes, stirrup arrangements, volume stirrup ratios and corrosion degrees. The corrosion of stirrups was accelerated by the fully-immersed electro-chemical method. Failure modes and effects of variables on force-displacement curves of the specimens were studied through axial compression tests. Results show that with the increase of corrosion rate, the initial stiffness, bearing capacity and ductility of the specimens decrease. The decline of bearing capacity is more obvious with a lower stirrup volume ratio. Furthermore, the bearing capacity model for rectangular columns with corroded stirrups was established based on the maximum stress of the confined concrete, the residual bearing capacity of longitudinal reinforcement and the strength of concrete cover after corrosion. The accuracy and applicability of the proposed model were verified through a comparison between the predicted and experimental results. The proposed model can be used for the estimation of residual bearing capacity of corroded columns as well as the safety assessment. © 2024 Tsinghua University. All rights reserved.