根据钢-混结合梁与钢-混结合段中PBL剪力键不同的受力状态,设计了两种试验构造类型共9组36个PBL剪力键试件的推出试验,测试了各组试件的相对滑移及构件应力水平。试验结果表明:两种构造形式的PBL剪力键试件的荷载-滑移曲线、破坏过程及破坏形态截然不同;在构造参数相同的情况下,钢一混结合段中PBL剪力键的极限承载力、极限荷载、抗剪刚度和延性系数都要优于钢-混结合梁中的PBL剪力键;在进行PBL剪力键的推出试验研究时,有必要根据其受力状态选择相对应的试验构造;PBL剪力键的承载力、抗剪刚度、延性系数的影响因素有混凝土强度、开孔直径、开孔钢板厚度、贯穿钢筋直径、键群的布置形式以及试验构造等。需要尽快制定PBL剪力键的标准试验方法,以方便对其进行系统的研究以及促进其在钢-混组合结构中的应用。
According to the different stress states of PBL shear connectors in steel-concrete composite beam and steel- concrete joint section, push-out tests of 36 specimens in 9 groups of the two construction forms are conducted to test the relative slippage and component stress level of specimens. Following conclusions can be drawn from the experiments. The load-slip curve, failure mechanism and failure mode of PBL shear connector are quite different in two construction forms. With the same construction parameter, the ultimate bearing capacity, ultimate load, shear stiffness and ductility factor of PBL shear connectors in steel-concrete joint section are better than that in steel-concrete composite beam. The structure of test models should correspond with the stress state of PBL shear connecters when the push-out tests are conducted. The influencing factors of the bearing capacity, shear stiffness and ductility factor of PBL shear connectors include concrete strength, perforated diameter, thickness of the perforated plate, diameter of the perforated rebar, layout of connectors and the test structure. Standard test method of PBL shear connector should be developed as soon as possible, so as to promote the systematic research and its application in steel-concrete composite structure.