Experimental study on seismic performance of CFRP bar reinforced concrete columns with magnetorheological damper

Concrete column with Carbon Fiber Reinforced Polymer (CFRP) bars as longitudinal reinforcement have good self-centering performance, but its energy dissipation property is relatively weak. This article proposed a method of adjust the energy dissipation capacity of the column without affecting its self-centering performance by installing magnetorheological (MR) damper outside the column. To verify the feasibility of this method, pseudo-static tests were conducted on a MR damper, one ordinary reinforced concrete column (RCC), and two CFRP bar reinforced concrete columns with MR damper (CFRP80 and CFRP150), and the currents of the MR damper were 80 mA and 150 mA. The experimental results showed that installing MR damper can effectively improve the carrying capacity, energy dissipation property and stiffness of CFRP bar reinforced concrete columns, and the greater the energizing current of the MR damper, the more obvious these effects. Compared with RCC, CFRP bar reinforced concrete columns have better self-centering performance and ultimate deformation. The residual drifts of RCC, CFRP80 and CFRP150 at the 4 % drift level were 2.50 %, 0.62 % and 0.58 %, respectively. The ultimate drifts of RCC, CFRP80 and CFRP150 were 2.79 %, 4.26 % and 4.34 %, respectively. In addition, the use method of the MR damper can ensure that it does not affect the self-centering performance of CFRP bar reinforced concrete columns.