钢-聚丙烯混杂纤维混凝土柱抗震性能试验研究

考虑纤维种类、轴压比、剪跨比、配筋率等因素,设计制作22根钢-聚丙烯混杂纤维混凝土框架柱试件,通过低周反复荷载试验研究柱的抗震性能。基于实测的荷载-位移滞回曲线、骨架曲线及破坏形态,探讨纤维种类等因素对试件耗能能力和延性的影响规律,建立钢-聚丙烯混杂纤维混凝土柱位移延性系数计算公式。结果表明,钢-聚丙烯混杂纤维在增强柱耗能能力方面优于钢纤维或聚丙烯纤维,并随轴压比的增大,其发挥作用越明显;剪跨比、纵筋配筋率和配箍率对混杂纤维混凝土柱耗能能力和延性的影响与普通混凝土柱类似,随其增大而提高。

On seismic behavior of steel-polypropylene hybrid fiber reinforced concrete columns

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.