PBL剪力键承载能力试验研究

Test Study of Bearing Capacity of PBL Shear Connectors

为研究灌注材料与钢板的粘结作用力、孔内榫作用力、贯穿钢筋作用力对PBL剪力键承载力的影响,以某混合梁斜拉桥的钢-混结合段剪力键实际结构为依托,分别以C55混凝土和活性粉末混凝土为灌注材料,设计制作了16个PBL剪力键试件进行单板插入式加载试验,分析了试件的荷载~相对位移曲线、破坏形态及各组成部分占总承载力的比重。结果表明：各试验试件均为传剪构件剪断破坏,在承载力及延性方面,采用RPC作为灌注材料的试件均优于采用C55混凝土作为灌注材料的试件;设置贯穿钢筋后,PBL剪力键的承载力及延性性能均有明显的提高;灌注材料与钢板的粘结作用力、孔内榫作用力、贯穿钢筋作用力分别约占PBL剪力键总承载力的20%、40%、40%。

To study the influences of the bond acting forces between the casting materials and steel plate, the tenon acting forces in the shear pockets and through reinforcement acting forces on the bearing capacity of the PBL shear connectors, the actual structures of the shear connectors used for the steel and concrete joint section of a hybrid girder cable-stayed bridge were taken as a case study. The C55 concrete and the reactive powder concrete （RPC） were respectively used as the casting materials, 16 PBL shear connector specimens were designed and fabricated, the plug- in load tests of the single plate were made and the load～ relative slip displacement curves, the failure modes of the specimens and the proportions of the various acting forces accounting for the total bearing capacity of the shear connectors were analyzed. The results of the analysis show that the specimens are all the shear transfer components that fail in shear. As regards the bearing capacity and ductility, the specimens using the RPC as the casting material are superior to those using the C55 concrete. After the through reinforcement are arranged, the bearing capacity and ductility of the shear connectors have been significantly increased and the bond acting forces, ten- on acting forces and through reinforcement acting forces respectively account for about 20%, 40% and 40 % of the total bearing capacity of the shear connectors.