Abstract:In order to reduce the bond degradation of beam reinforcement bars in beam-column exterior joints with HRB600 reinforcement bars, the beam-column exterior joints with overall or local steel fiber concrete were designed. The low-cycle loading tests were carried out on two ordinary concrete beam-column exterior joint with HRB600/HRB400 reinforcement bars, and two steel fiber concrete beam-column exterior joints with overall or local steel fiber concrete and HRB600 reinforcement bars. The failure modes, hysteresis curves, energy dissipation, ductility, shear deformation in the core zone and bond degradation of beam reinforcement bars were analyzed. The research results showed that the joints with HRB600 reinforcement bars exhibited higher bearing capacity, energy dissipation capacity and ductility under low-cycle loading, but the bond degradation between HRB600 reinforcement bar and ordinary concrete degraded too quickly. The exterior joint reinforced by overall or local steel fiber concrete exhibited slower bond degradation of HRB600 beam reinforcement bars, slighter failure mode, smaller shear deformation in the joint core area, and larger energy dissipation capacity. The beam-column exterior joint with overall steel fiber concrete had higher ductility and energy dissipation capacity compared with the beam-column exterior joint with local steel fiber concrete, and the bond degradation of HRB600 beam bars was slower.