部分高强筋预制混凝土框架节点抗震性能研究

Aseismic behavior of precast concrete frame joints with partial high strength tendons

为了研究新型部分高强筋预制框架节点的抗震性能,对4个后浇整体式预制梁柱节点及1个现浇对比节点进行低周反复荷载试验研究,探讨节点的破坏形态、滞回曲线、位移延性系数、耗能能力及刚度退化。试验结果表明,节点核心区设置附加钢筋,能够有效的提高节点的承载能力及变形能力,同时能够实现梁端的塑性饺外移及提高节点的耗能能力;通过与现浇节点对比发现,预制节点的耗能能力在加载前期都弱于现浇节点,但是随着荷载的进一步施加,预制节点表现出了强于现浇节点的耗能能力;所有预制节点的冈慷在弹性阶段都小于现浇节点,但当节点进入屈服阶段后,预制节点的刚度都大于现浇节点。经以上试验结果分析可知,部分高强筋预制框架节点具有较大的安全储备,能够在具有抗震设防的地区规模推广应用。

In order to study aseismic performance of a new prefabricated concrete frame joints with partial high strength tendons, low cyclic repeated load tests were performed for 4 post-pouring integral prefabricated beam-column joints and 1 cast-in-situ comparative one to explore their failure mode, hysteresis curve, displacement ductility coefficient, energy dissipation capacity and stiffness degradation. The test results showed that additional steel bars located in joint,s core area can effectively improve joint * s load-bearing capacity and deformation one, realize plastic hinges' off-shifting at beam ends and improve joint' s energy-dissipation ability;compared with the cast-in-situ joint, the energy-dissipation ability of prefabricated ones is weaker within the initial stage of loading, with increase in loading, the latter' s energy dissipation ability is stronger than that of the former;in elastic stage, the stiffness of all prefabricated joints is smaller than that of the cast-in-situ one, while in yield stage, the stiffness of the latter is larger than that of the former;thus, prefabricated frame joints with partial high strength tendons have larger safety stock and can be popularized and applied in areas with seismic fortification.