Effect of Bond Parameters on Recoverability of RC Bridge Columns Reinforced with Ordinary Rebars and Steel Fiber Composite Bars

In this study, effects of bond parameters on post-earthquake recoverability of RC bridge columns reinforced with ordinary deformed bars and innovative composite bars: steel fiber composite bars (SFCBs), are studied. A computer program is employed to investigate the effect of bond parameters on column post-yield stiffness and residual deformations. Then, the required recoverability is examined for experimentally tested columns with different unbonded length of longitudinal ordinary rebars, available from literature, and two tested scale-model RC bridge columns reinforced with different products of SFCBs, i.e. steel basalt-fiber composite bars (SBFCBs) and steel carbon-fiber composite bars (SCFCBs). The study showed that weaken bond between deformed bars and the surrounding concrete has no clear effect on column residual deformations, however, mitigation of residual deformations could be when columns are reinforced with SFCBs. Furthermore, bond effect could play an important role in the recoverability of structures reinforced with SFCBs, where both the achieved post-yield stiffness and residual deformations could be controlled.