Axial Compression Behavior of Steel Reinforced Concrete Columns after Chloride-Induced Corrosion

Corroded steel reinforced concrete (CSRC) structures in coastal environments face a serious durability issue. This paper investigated the axial compressive performance of CSRC columns experimentally. Twelve CSRC columns with different corrosion ratios and slenderness ratios were designed and subjected to electrochemical corrosion tests and axially loaded tests to reveal their failure mode and performance deterioration laws. The test results revealed that the ultimate bearing capacity and stiffness of CSRC specimens decreased significantly, while the ductility index decreased slightly, with increasing corrosion ratio and slenderness ratio. Furthermore, comparisons were made between the experimental results of the ultimate bearing capacity of CSRC columns and the calculated results from three different design methods (Eurocode 4, JGJ 138–2016, and ANSI/AISC 360–22). A modified design formula was derived theoretically for the ultimate bearing capacity of CSRC columns, based on Eurocode 4, considering the cracking and confinement effects after corrosion. Finally, a new finite element modeling method for simulating CSRC columns was proposed, and different finite element models considering different effects were compared to further verify the rationality and necessity of considering both effects simultaneously in the modified bearing capacity calculation formula.