Behavior of corroded circular RC columns strengthened by C-FRCM under cyclic loading

This study presents an experimental investigation on the seismic behavior of corroded reinforced concrete (RC) columns strengthened by carbon-fabric reinforced cementitious matrix (C-FRCM). To this end, cyclic loading tests were conducted on seven circular RC columns, six of which were suffered from corrosion with duration of 360 days. Four of the corroded specimens were afterwards strengthened by C-FRCM composites. Among these, two specimens were externally bounded with two layers of C-FRCM, the other two specimens were externally bounded with three layers of C-FRCM. After the corrosion process, cyclic loading tests were conducted on the specimens, wherein various axial compression (AC) ratios were considered. The test results show that the secant stiffness, strength, ductility and energy dissipation capacity of corroded specimens were significantly reduced compared with those of the uncorroded counterparts. This phenomenon is severer with larger AC ratio. The C-FRCM can effectively enhance the stiffness, strength, ductility and energy dissipation capacity of the corroded RC columns, wherein two layers of C-FRCM is considered to be desirable for the C-FRCM strengthening approach.