Seismic Performance of Precast Segmental Bridge Columns Reinforced with Both Stainless-Steel Bars and GFRP Bars

An innovative precast segmental bridge column (PSBC) was proposed to achieve a better durability performance in an aggressive coastal environment, which was reinforced with both longitudinal stainless steel (SS) bars and glass fiber reinforced polymer (GFRP) bars. Four 3/20-scale PSBCs with various ratios of GFRP to SS bars were tested quasi-statically. Test results showed that compared to SS-reinforced PSBCs (SR-PSBCs), the SS-GFRP-reinforced PSBCs (SFR-PSBCs) exhibited higher displacement ductility, less stiffness degradation, lower postyield stiffness ratios, and smaller residual drift ratios, although they presented lower lateral loading capacity and energy dissipation. Increasing the ratio of longitudinal GFRP bar to SS bar in SFR-PSBCs resulted in higher displacement ductility performance and more gentle stiffness degradation behavior. Furthermore, the increase of axial load affects the seismic behavior of SFR-PSBCs in an unfavorable way, which could result in severer damage, significant reduction in the displacement ductility, faster stiffness degradation beyond the peak lateral strength point, and increase in the residual displacement.