HRB600级钢筋钢纤维高强混凝土柱抗震性能研究

为研究HRB600级钢筋高强高性能混凝土柱的抗震性能,进行了6根大尺寸方形截面(600 mm×600 mm)混凝土柱在高轴压比条件下的低周反复荷载试验,包括2根HRB600级钢筋普通高强混凝土柱和4根HRB600级钢筋钢纤维高强混凝土柱,对比分析了各试件的破坏形态、滞回性能、承载力、刚度退化规律、延性和耗能能力。在试验基础上建立了HRB600级钢筋钢纤维高强混凝土柱的恢复力模型。研究结果表明:钢纤维可以减小高强混凝土柱的裂缝宽度,有效防止混凝土保护层脱落,减小柱的残余变形,提高柱的震后恢复性能;HRB600级钢筋钢纤维高强混凝土柱的变形能力良好,随着钢纤维掺量的增加,高强混凝土柱的位移延性系数逐渐增大;基于试验数据建立的HRB600级钢筋钢纤维高强混凝土柱恢复力模型计算精度良好;该类型柱可较好地满足现行抗震设计规范要求,宜于推广应用。

Seismic behavior of steel fiber high-strength concrete columns with HRB600 steel bars

In order to investigate the seismic behavior of high-performance concrete columns with HRB600 steel bars, reversed cyclic load tests on six high-strength concrete columns with square section of 600mm×600mm were carried out under high axial compressive forces. The specimens included two normal concrete columns with HRB600 steel bars and four steel fiber concrete columns with HRB600 steel bars.The failure modes, hysteretic properties, bearing capacity, stiffness degradation, ductility and energy dissipation capacity of the test specimens were compared and analyzed. A restoring force model for steel fiber high-strength concrete column with HRB600 steel bars was established based on the test results. The results show that steel fibers can reduce the crack width of the high-strength concrete columns, prevent the concrete cover from peeling off, decrease the residual deformation of the columns and improve their restorability after earthquakes. The steel fiber high-strength concrete columns with HRB600 steel bars have good deformation capacity, and furthermore, the displacement ductility coefficient increases with the increase of the steel fiber content. The restoring force model of the steel fiber reinforced concrete columns with HRB600 steel bars based on experimental data is calculated accurately, and this kind of columns have good seismic performance and can satisfy the requirements of the seismic design code, making them suitable for engineering application.