Safety-Enhancement of RC Bridge Frame Columns Using Bond-Based Damage-Controllable Steel Basalt-Fiber Composite Bars

摘要

Existence of positive post-yield stiffness and mitigation of both residual deformation and damage level are critical indices in the performance of reinforced concrete (RC) bridge frame columns to assure the quick recovery of bridge original functions after a massive earthquake. In this study, because bond between longitudinal reinforcement and concrete is a key factor controlling the performance of RC structures, effects of bond parameters on the required post-earthquake recoverability of RC bridge columns reinforced with innovative composite rebars: steel fiber composite bars (SFCBs), are studied. Results of experimentally tested columns reinforced with different products of SFCBs are firstly presented. Afterward, a computer program is employed to investigate the effect of bond parameters on the recoverability indices (post-yield stiffness, residual deformations, and damage level) of columns reinforced with steel basalt-fiber composite bars (SBFCBs). The study showed that weaked bond between SFCBs and the surrounding concrete at plastic hinge zone would play an important role in the recoverability of structures reinforced with SBFCBs, where the achieved post-yield stiffness, residual deformations, and damage level could be controlled.