高强箍筋高强混凝土梁柱节点抗震性能试验研究

EXPRIMENTAL STUDY ON SEISMIC BEHAVIOR OF HIGH-STRENGTH CONCRETE FRAME JOINTS WITH HIGH-STRENGTH STIRRUPS

为研究高混凝土梁柱节点的抗震性能,进行了4个高强箍筋混凝土节点和1个普通箍筋混凝土节点的低周往复荷载加载试验,研究了高强混凝土节点的破坏形态、滞回特性、耗能能力、受剪性能及箍筋的应力水平,分析了箍筋强度、体积配箍率和箍筋形式对节点承载力、延性、耗能和剪切变形的影响。结果表明:高强箍筋节点的破坏过程与普通箍筋节点类似;提高箍筋屈服强度对节点的承载力提高效果有限,但可有效提高位移延性和耗能能力,同时限制了节点核心区的剪切变形;试件达到极限位移时,普通箍筋试件箍筋已屈服,复合高强箍筋试件箍筋强度发挥比较充分,表现出较好的抗震性能。

Four concrete frame joint specimens with high-strength stirrups and one with normal strength stirrups were tested under low cyclic reversed loading to investigate the seismic behavior of high-strength concrete frame joints. The failure pattern, hysteretic behavior, energy dissipation, shear behavior, and stirrup stress of high-strength concrete frame joints were studied. The influence of stirrup yield strength, stirrup volume ratio, and stirrup configuration on the shear bearing capacity, ductility, energy dissipation, and shear deformation of specimens were analyzed. The results indicate that the failure process of specimens with high-strength stirrups are similar to specimens with normal-strength stirrups; increasing stirrup yield strength has limited enhanced effect on bearing capacity of specimens, but the ductility, energy dissipation, and restriction of shear deformation in the joint core are improved effectively. At the ultimate displacement, normal-strength stirrups reach their yield strength, and the stirrup strength is nearly fully developed in specimens with composite high-strength stirrups. The specimens with composite high-strength stirrups show better seismic performance.