核心区配箍率影响下HRB500E梁柱节点抗震研究

Seismic Performance Research of the Beam-Column Joint with HRB500E Under Different Core Region Stirrup Ratios

核心区箍筋可以约束混凝土同时改变梁柱节点传力机理。为研究不同核心区配箍率下高性能钢筋梁柱节点的抗震性能,设计高、低剪压比下共6个配置高性能钢筋(HRB500E)的足尺试件,并对其进行拟静力加载试验。本文分高、低两种剪压比情况下研究了配置不同核心区体积配箍率时梁柱节点的破坏模式、裂缝发展、滞回曲线、延性系数和能量耗散性能。研究结果表明:低剪压比情况下,随着核心区配箍率的增加,试件滞回曲线越来越饱满,试件的延性性能显著提高;高剪压比情况下,随着核心配箍率的增加,节点核心区越来越完整,试件的梁端承载力和延性系数有一定的提高。无论高剪压比还是低剪压比情况下,核心区配箍率都可以改变梁柱节点的破坏模式,且过低的配箍率会使试件表现出较差的耗能性能。

Core region stirrups could constraint the concrete in core region and change joint’ s mechanical behavior. To investigate the seismic performance of high performance reinforcement （HRB500E） beam-column joint with different core region stirrup ratio, six full-scale specimens with low and high shear compression ratio were designed and tested under quasi-static load. The failure modes, cracks development, hysteretic curve, ductility coefficient and energy-dissipation performances of the specimens were studied in both high shear compression ratio and low shear compression ratio situation. Results indicated that：when shear compression ratio is low, with the core region stirrup ratio increasing, the hysteretic curve become plumper, and the ductility coefficient increased significantly. When shear compression ratio is high, with the stirrup ratio increasing, more complete core region joints were provided, and the bearing capacity as well as the ductility coefficient was slightly improved. In both low and high shear compression ratio situation, core region stirrups ratio could change the failure mode of the beam-column joint, and the very low stirrups ratio could result in poor energy-dissipation.