Experimental investigation on seismic behavior of corroded RC columns under artificial climate environment and electrochemical chloride extraction: A comparative study

Abstract

Corrosion of reinforcement bars can cause reinforced concrete (RC) columns more vulnerable under seismic loads. In this study, the seismic behavior of corroded RC columns was experimentally studied with a focus on the comparison between two different accelerated corrosion techniques by using artificial climate environment (ACE) and electrochemical chloride extraction (ECE). To do this, six RC square columns were designed and fabricated as the test specimens. The test specimens were categorized into two groups with a low level and a high level of axial compression ratio (i.e., 0.1 and 0.45), respectively, and each group includes three test specimens, i.e., an uncorroded column and two corroded columns under ACE and ECE techniques. An X-ray diffraction approach was used to examine the major ingredients of corrosion products attached on the corroded reinforcement bars under ACE and ECE techniques. The column specimens were subjected to repeated cyclic loadings, and the failure modes, hysteresis and backbone curves, stiffness degradation, ductility level and energy dissipation of the specimens corroded under different techniques were compared. The results show that, under a consistent target corrosion level, the ECE corrosion technique can cause more significant damage to the corroded RC columns than the ACE corrosion technique, leading to a change of failure mode and worse hysteretic performance.