低周反复荷载下钢纤维高强混凝土柱延性试验研究

通过26根钢纤维高强混凝土柱在低周反复荷载作用下的压弯性能试验,研究了轴压比、钢纤维含量特征值、箍筋含量特征值、剪跨比和纵向配筋等因素对钢纤维高强混凝土柱延性性能的影响规律,结果表明:钢纤维对改善高强混凝土柱的脆性破坏性质并提高其延性具有明显效果,但钢纤维和箍筋对高强混凝土柱的延性提高作用机理不同,不能采用钢纤维等量(体积率相同)取代箍筋的方法使高强混凝土柱获得等同的延性性能。提出了钢纤维高强混凝土柱的位移延性系数计算公式,可供工程设计应用参考。

DUCTILITY OF STEEL FIBER REINFORCED HIGH-STRENGTH CONCRETE COLUMNS UNDER CYCLIC LOADING

Based on the test of 26 steel fiber reinforced high-strength concrete columns under cyclic loading, the factors affecting the column ductility are analyzed. These factors include the axial compression ratio, the characteristic value of stirrups, the characteristic value of steel fiber, the span to depth ratio and the longitudinal reinforcement. It is demonstrated that the steel fiber has better effects on improving the brittle failure state and increasing the seismic ductility of high strength concrete columns. But the mechanisms of the steel fiber and the stirrups for reinforcing the ductility of high strength concrete columns are different. As a result, the equal seismic ductility cannot be obtained by replacing the stirrups with the equivalent volume ratio of steel fiber. A formula for calculating the displacement ductility coefficient is proposed.