Investigation on Seismic Performance of Reinforced Concrete Frame Retrofitted by Carbon Fiber-Reinforced Polymer

Abstract

In order to improve the seismic performance of reinforced concrete (RC) frames, carbon fiber-reinforced polymer (CFRP) was used to retrofit reinforced concrete frame structures. The comparison pseudo-static test results show that the peak load, initial stiffness and ductility of the CFRP retrofitted model were increased by 43.89%, 39.27% and 30.1%, respectively. Based on the parametric study of the finite element model, the contribution of CFRP to the seismic upgrading effect of RC columns was quantitatively revealed, and an optimized design of retrofitted CFRP was proposed. The results show that the peak load, ductility and energy dissipation capacity of the whole structure are improved by using CFRP full-wrap reinforcement and strip reinforcement models with different coverage areas. The damage degree of the column decreases, the damage degree of the beam increases, and the failure mode changes from “column hinge” to “beam hinge”. Simultaneously, different CFRP reinforcement areas and the distance between strip CFRP have different reinforcement effects on concrete structures. Based on the investigation results, the recommended ratio of CFRP strip to spacing is 1 to 1.25.