后张无黏结预应力干式连接梁柱节点抗震性能试验研究

Experimental study of seismic performance of unbonded post-tensioned pre-stressed beam-to-column dry connections

为研究后张无黏结预应力干式装配梁柱节点在低周往复荷载作用下的抗震性能,对其进行了拟静力试验研究。试验中设计了2个常规现浇梁柱节点和4个装配式梁柱节点,包含中节点和边节点。对比分析了现浇节点和装配节点滞回性能、刚度、承载能力以及变形能力差异。试验结果表明：试验中设计的后张无黏结预应力装配式梁柱节点试件在初始刚度、承载能力、变形能力以及损伤控制等方面均优于传统的现浇节点试件,耗能能力略低;进一步研究了后穿耗能钢筋无黏结段位置对装配节点性能的影响,认为后穿耗能钢筋无黏结段设置在柱外时,装配节点呈现更高的耗能能力和变形能力;装配式节点预应力钢绞线在1/20大位移角下仍能保持弹性,梁柱接触面基本无摩擦滑移,该类装配式节点具有良好的整体性和安全性。

Quasi-static cyclic tests were carried out to investigate the hysteretic behavior, stiffness, bearing capacity and deformation capacity of beam-to-column dry connections assembled by post-tensioned tendons. Two conventional and four novel assembled beam-to-column connection specimens were tested, including interior and exterior connections. The difference in hysteretic behavior, stiffness, bearing capacity and deformation capacity of the conventional and the assembled beam-to-column connections were compared. The test results show that the initial stiffness, ultimate bearing capacity, and deformation capacity of the assembled connection specimens are all better than those of the conventional connection specimens, although the energy-dissipating capacity of the former is less than the latter. Moreover, the influence of the position of the unbonded range of the steel rebar on the behavior of assembled connection specimens was studied. The beam-to-column connections with the unbonded range of the steel rebars located outside the column exhibit better energy dissipation and deformation capacities than those with the unbonded range of the steel rebars located in the column. The prestress tendons of the assembled connection specimens maintain elastic under 1/20 rotation, and slippage between the surface of column and beam does not occur during the test. Generally speaking, the assembled connection specimens show good integrity and safety.