超高性能混凝土开孔板连接件抗剪性能研究

Research on the Shear Resistance of Ultra-High Performance Concrete Perfobond Rib Connectors

为探讨混凝土强度对开孔板连接件性能的影响,开展了6个开孔板连接件的插入式试验。通过分析连接件的破坏形态可知,所有的开孔板连接件中的贯穿钢筋均在开孔钢板和混凝土的界面处被剪断。在加载过程中,普通混凝土板出现了明显的表面裂缝,而超高性能混凝土板没有出现裂缝,超高性能混凝土抗裂性能良好。通过分析开孔板连接件的推出试验情况以及荷载—滑移曲线可知,连接件具有良好的延性,超高性能混凝土能显著提高开孔板连接件的承载能力和抗剪刚度。将开孔板连接件的插入式试验数值与其他学者的承载力公式预测的结果进行对比可知,现有研究得到的承载力公式相对保守。选择其中与超高性能混凝土开孔板连接件试验结果吻合良好的承载力公式进行相关的系数修正,提高了公式的计算精度,可以更好地支撑超高性能混凝土开孔板连接件的研究与推广工作。

In order to explore the influence of concrete strength on the bearing capacity of PBL connectors, 6 plug-in tests of PBL connectors are carried out. By analyzing the failure mode of the connectors, it can be seen that the transverse steel bars in all the PBL connectors are sheared at the interface between the concrete and the steel plate. During the loading process, the ordinary concrete slab shows obvious cracks, but the ultra-high performance concrete slab does not appear cracks, indicating that the ultra-high performance concrete has good crack resistance. By analyzing the test conditions of the bearing capacity of the PBL connector and the analysis of the load-slip curve, it is known that the transverse steel bar has good ductility, and the ultra-high performance concrete can significantly improve the bearing capacity and shear stiffness of the PBL connector. Comparing the plug-in test results of PBL connectors with the test data predicted by other scholars’ bearing formulas, the bearing capacity formulas obtained by other scholars are relatively conservative, and the bearing capacity that is in good agreement with the test results of ultra-high performance concrete PBL connectors is selected. The formula is corrected for related coefficients, which improves the calculation accuracy of the formula and can better guide the application of ultra-high performance concrete PBL connectors in actual projects.