Seismic behaviors of steel-FRP composite bar-reinforced engineered cementitious composites columns under reversed cyclic loads

Abstract

The combination of steel-FRP composite bar (SFCB) and engineered cementitious composites (ECC) in structures exposed to harsh conditions can offer benefits in mechanical performance and durability. In this study, the seismic behaviors of SFCB-reinforced ECC and concrete columns were investigated through reversed cyclic loading tests and the effects of matrix types, axial load ratios, and reinforcing bar types were discussed. The results showed that the SFCB-reinforced ECC columns experienced flexural failure characterized by SFCB fracture, whereas the SFCB-reinforced concrete columns failed owing to concrete crushing. The SFCB-reinforced ECC columns showed a 41.5 %− 116.3 % enhancement in deformation capacity and a 34.7 %− 65.2 % improvement in average energy dissipation coefficient compared with SFCB-reinforced concrete columns, which demonstrated that using ECC in SFCB-reinforced columns addressed issues of their low deformation and low energy dissipation capacity. In addition, the plastic hinge length of SFCB-reinforced columns increased substantially with the application of ECC, and the stiffness degeneration and residual deformation were reduced.