预应力全装配混凝土框架节点的抗震性能试验研究

Experimental study on seismic behavior of prestressed totally assembled concrete frame connection

通过对3个预应力全装配混凝土框架节点的拟静力试验,研究了普通钢筋的弯矩贡献(M_(s))与总弯矩(M_(pr))的比值、普通钢筋是否有无粘结段对节点抗震性能的影响;之后对其中2个节点进行修复,并重新进行拟静力试验,研究节点修复后的抗震性能。试验结果表明预应力全装配混凝土框架节点的破坏集中在节点区域的灌浆料垫层,梁柱基本没有破坏,梁身裂缝及核心区剪切裂缝较窄且均能闭合;预应力筋始终保持弹性,可实现节点的自复位性能;普通钢筋的弯矩贡献比越大,滞回曲线越饱满,耗能能力越强,但残余变形也越大;普通钢筋是否有无粘结段对节点的抗震性能影响较小;修复节点的破坏状态与未修复节点一致,破坏集中在节点区域的砂浆垫层;修复节点的抗震性能基本可以达到原节点的水平。

An quasi-static experimental study on 3 prestressed totally assembled concrete frame connection,is conducted.The effect of ratio of M_(s)(contribution of mild steel to M_(pr))and M_(pr)(probable flexural strength at a beamcolumn interface of a precast concrete beam of moment frame),whether the mild steel has unbonded section or not on the seismic behavior of connection,is investigated.Then two specimens are repaired and quasi-static tests on them are conducted to investigate the seismic behaviors of connection after repairing.The results show that the damage of prestressed totally assembled concrete frame connection is concentrated on the joint grout,the beams and columns suffer little or no damage,and there are less or no cracks on the beam and the joint core area;the prestressed tendons ramain elastic during the tests that guarantees pulling back the connection to the original location;the more fullness hysteretic behavior curve,and the more energy consumption by increasing the ratio of M_(s)and M_(pr),but the bigger residual deformation.Whether the mild steel has deboned section or not has less effect on the seismic behavior of connection,the damage states of repaired connection is concentrated on the joint grout coincided with original connection;the seismic behavior of connection after repairing can achieve that of the original specimens.