HRB600级钢筋高强混凝土柱抗震性能试验研究

为研究HRB600级钢筋高强混凝土柱的抗震性能，进行9根截面尺寸为600mm×600mm的高强混凝土柱在工程实际轴压比条件下的低周反复荷载试验，主要设计变化参数为钢筋等级、箍筋间距、混凝土强度和轴压比。对比分析各试件的破坏形态、滞回性能、承载力、延性、刚度退化和耗能能力，基于试验建立HRB600级钢筋高强混凝土柱的恢复力模型。结果表明：各试件的破坏形态相似，均为延性弯曲破坏，柱底出现塑性铰，纵筋屈曲，混凝土保护层脱落；HRB600级钢筋高强混凝土柱不仅具有较好的滞回性能以及变形与耗能能力，且震后可恢复性能相对较好；高强混凝土柱设计中，HRB600级钢筋与C80混凝土匹配应用效果较优；合理配置箍筋，可使HRB600级钢筋高强混凝土柱在高轴压比条件下的延性系数大于4.0；文章基于足尺构件试验建立的恢复力模型，以期可为相关工程结构抗震弹塑性分析提供参考。

Experimental study on seismic behavior of high-strength concrete columns with HRB600 steel bars

 In order to investigate the seismic behavior of high-strength concrete columns with HRB600 steel bars, cyclic loading tests on nine high-strength concrete columns reinforced with HRB400 and HRB600 steel bars were carried out under practical axial compression ratio. The main design parameters of specimens were steel grade, stirrup spacing, concrete strength and axial compression ratio. The failure modes, hysteretic properties, load-carrying capacity, ductility, stiffness degradation and energy dissipation capacity of specimens were analyzed and compared. Based on the test results, a restoring force model of high-strength concrete column with HRB600 steel bars was established. The research results indicate that the specimens have similar failure modes, which appear to be ductile bending failure with plastic hinge occurring at column bottom, local buckling of longitudinal reinforcement and spalling of concrete cover. It is shown that the high-strength concrete columns with HRB600 steel bars possess good hysteretic behavior, deformability and energy dissipation capacity as well as the seismic resilience. In the design of high-strength concrete columns, the conjunction of HRB600 steel bars and C80 grade concrete has good application performance. With reasonable design of stirrups, the ductility ratio of the high-strength concrete columns with HRB600 steel bars under a high axial compression ratio can be greater than 4.0. The restoring force model established from full-scale specimen tests has satisfactory calculation accuracy, which can be used for seismic elastic-plastic analysis of related engineering structures.