Abstract：In this study, the seismic performance of twenty-two steel-polypropylene hybrid fiber reinforced concrete columns were tested under axial and low reversed cyclic horizontal loads, considering the effects of fiber types, axial load ratio, shear span-depth ratio and reinforcement ratio. Based on the measured load-displacement hysteresis loops, skeleton curves and failure modes, the influences of the aforementioned factors on the energy dissipation capacity and ductility of test specimens were examined and evaluated, and then the calculation formula for the displacement ductility coefficient of the steel-polypropylene hybrid fiber reinforced concrete columns was established. The test results reveal that compared with steel fiber or polypropylene fiber, steel-polypropylene hybrid fiber exhibits a better performance in enhancing the energy dissipation capacity of the structural column, which tends to be further improved as the axial load ratio increases. The ductility and energy dissipation capacity of hybrid fiber-reinforced concrete columns can be affected in a similar way as the conventional RC columns by the shear span-depth ratio, the longitudinal reinforcement ratio and the stirrup ratio, so that the capacities generally increase with the increases of the ratios.
