梁纵筋锚固板锚固装配整体式梁柱边节点抗震性能试验

Seismic behavior of assembled monolithic beam-column exterior joints with beam longitudinal rebars anchored by heads

摘要:

为研究柱纵筋套筒挤压连接、梁纵筋锚固板锚固的叠合梁-预制柱后浇核心区装配整体式边节点的抗震性能，进行了1个核心区剪切破坏和1个梁端弯曲破坏的边节点试件PEJ1和PEJ2的拟静力试验.结果表明：试件PEJ1核心区箍筋先于梁纵筋屈服，核心区混凝土严重剪切破坏，试件PEJ2核心区箍筋未屈服，梁固端混凝土压溃、纵筋严重屈服，2个试件均实现了预期的破坏形态；2个试件的力-位移滞回曲线有一定程度的捏拢，试件PEJ1滞回曲线捏拢程度略大、峰值后骨架线下降较快；2个试件的承载力试验值与规范相应公式计算值的比值分别为1.30和1.26，等效极限层间位移角分别为1/28和1/22；试件PEJ1峰值时梁变形为主，极限点时核心区剪切变形为主，试件PEJ2梁变形为主，核心区剪切变形占总变形不到5%；2个不同破坏形态试件的梁纵筋锚固板锚固未失效，后浇核心区装配式边节点梁纵筋可采用锚固板锚固.

Abstract:

To study the seismic behavior of assembled monolithic beam-column joints, quasi-static tests of one precast exterior joint PEJ1 with the shear failure of joint core area and one precast exterior joint PEJ2 with the flexural failure of beam fixed end were carried out. For the specimen PEJ1, core area hoops yield first and the core concrete fails in shear mode obviously. For the specimen PEJ2, concrete of beam fixed end crushes and beam longitudinal rebars yield while core area hoops don′t yield. The two specimens both fail in the expected failure modes. The hysteretic loops of the two specimens have a certain extent of pinch while the specimen PEJ1 shows a slightly larger extent of pinch. The skeleton curve of the specimen PEJ1 declines rapidly after peak load. The measured load-carrying capacity of the precast joints, which fail in shear mode in the joint core area and flexural mode at the beam fixed end, respectively are 1.30, 1.26 times as large as the calculated capacity according to the formulas in the current design code. The equivalent ultimate drift ratios of the two specimens are 1/28 and 1/22. The specimen PEJ1 is dominated by deformation of the beam at the peak point and shear deformation of the core area at the ultimate point. The specimen PEJ2 is dominated by deformation of the beam during the whole experiment while the contribution of shear deformation of the core area is less than 5%. The anchor failure of the beam longitudinal rebars does not occur. In the precast exterior joints with different failure modes, utilizing heads to anchor beam longitudinal rebars is feasible.