芯梁增强装配式混凝土框架节点抗震性能试验研究

Experimental study on seismic behavior of assembled concrete frame joints strengthened with core beams

提出一种键槽内采用芯梁增强的预制混凝土框架梁柱节点,为了验证该改进型节点的抗震性能,对节点进行低周反复荷载试验,考察节点的破坏过程及破坏形态,分析节点的滞回曲线、位移延性系数及耗能能力。通过试验发现,在键槽内设置芯梁能够提高节点的承载能力,同时键槽底部混凝土不会过早被压溃。改进型节点的总体耗能能力仍然弱于现浇节点。预制梁底部钢绞线伸入对面键槽内及芯梁架立筋对梁柱结合处的强度有所增强,使得梁端塑性铰外移,从而可以减小节点区的变形。但改进型装配式混凝土框架节点的抗震性能弱于较现浇节点,还需对节点做进一步的改进研究。

A new precast concrete frame beam-column joint strengthened with core beams in the keyway was proposed. In order to verify the seismic performance of the joint, a low-cycle reversed loading test was carried out to examine the destruction process of each joint, failure pattern, hysteresis curve, ductility coefficient and energy dissipation capacity of the joint were analyzed. It is found through the experiment that the core beam can be installed in the keyway to increase the bearing capacity of the joint, and the concrete at the bottom of the keyway can not be crushed prematurely. The overall energy consumption of the improved joint is still weaker than the cast-in-place joint. The bottom strand of the prefabricated beam extends into the opposite keyway and supporting reinforcement of core beams can enhance the strength of the beam and column joint. In general, the seismic performance of the improved fabricated concrete frame joints is weaker than that of the cast-in-place joints, and the joints need to be further improved.