PBL与PZ型剪力连接件抗拉拔性能试验

Experimental Research on Pull-out Behavior of PBL Shear Connector and Puzzle Shaped Composite Dowel

采用12个PBL和3个PZ型剪力连接件试件,通过一套自主设计的单调加载装置,进行极限抗拉拔承载力、相对位移、剪力键应变和破坏模式的测试试验,比较了开孔大小、埋置深度以及剪力键类型对试件极限抗拉拔承载力、初始开裂荷载和破坏模式的影响;并根据试验结果拟合了PBL剪力键极限抗拉拔承载力的计算公式。研究结果表明:加大孔径能直接提高PBL剪力键的极限抗拉拔承载力,当孔径由0 mm增长到30 mm,极限抗拉拔承载力增长率最大可达34.5%;埋置深度的增加较孔径能更显著地提升剪力键的极限抗拉拔承载力,当埋深由110mm增长至225 mm,PBL和PZ型剪力连接件对应的极限抗拉拔承载力的增长率可分别达到224%和165%;PZ型剪力连接件较相同埋深的PBL剪力键有更大的极限抗拉拔承载力,同时由于其良好的疲劳性能,不同几何尺寸和构造的PZ型剪力连接件力学性能的研究工作有待进一步开展。

The pull-out behavior of the PBL shear connector and the PZ shaped composite dowel, a total of 15 specimens,was studied by using a serf-designed monotonic loading equipment, aimed to study the ultimate uplift capacity, initial crack load, failure pattern and strain states of the steel web during the loading progress, the influence of the hole size, depth of embedment and form of the shear connector were considered. Based on the results of the PBL shear connectors, the calculation formula for ultimate pull-out bearing capacity was established. The results showed that the enlargement of the hole size or embedment depth could lead to direct increase on the ultimate pull-out bearing capacity of these two shear connectors. Ceteris paribus, the PZ shaped dowel has bigger bearing capacity than the PBL one, and better fatigue property based on other researchers＇ work, which could lead to further study on the mechanical property of the PZ shaped dowel with various geometric dimensions.