高强钢筋钢纤维混凝土框架中节点抗震性能试验研究

Experimental research on seismic behavior of frame interior joints with high strength reinforcing bars and steel fiber concrete

为研究配置高强钢筋梁柱节点抗震性能同时改善配置高强钢筋所引起的框架节点梁筋滑移量大的问题,在混凝土中加入钢纤维应用于节点的不同范围,对2个配置HRB600/HRB400钢筋的普通混凝土节点和2个配置HRB600钢筋的钢纤维混凝土节点进行低周反复荷载试验,探究钢筋强度、钢纤维范围对框架中节点抗震性能的影响。对比分析框架中节点的破坏特征,研究节点耗能能力、累积损伤、位移延性、梁筋滑移量等抗震性能指标。研究结果表明,所有试件均发生节点核心区剪切破坏,提高节点的梁钢筋等级能够显著提高节点的承载能力和耗能能力,但梁筋滑移量增加。在节点构件中采用钢纤维混凝土整体增强或局部增强均能够有效减少裂缝宽度和梁筋滑移,改善配置HRB600钢筋节点的破坏形态和滞回性能,提高耗能能力和延性性能,减轻累积损伤程度并减缓刚度退化。

This paper designs frame interior joints with overall or local steel fiber concrete to study th seismic performance of beam-column joints with high strength reinforcing bars and improve the large measured slip due to the usage of high strength reinforcing bars.Two normal concrete joins with HRB600/HRB400 reinforcing bars and two steel fiber concrete joins with HRB600 reinforcing bars were tested under reversed cyclic loading.The failure characteristic,hysteretic curves of specimens were obtained.The energy dissipation,cumulative damage,displacement ductility,and slip of beam reinforcement were analyzed.The results showed that shear failure of the connection core occurred in all joint specimens.The bearing capacity and energy dissipation capacity were improved by enhancing the reinforcement bar grade,whereas the measured slip of beam reinforcement increased.The crack width and slip of beam reinforcement in specimens with overall or local steel fiber concrete were effectively reduce.The failure mode,hysteretic behavior,energy dissipation capacity and ductility were improved and the cumulative damage and stiffness degradation were alleviated.