【摘要】 为改善钢-混凝土组合梁负弯矩区混凝土受拉易开裂的不足，同时满足桥梁结构可拆卸、易更换的需求，设计了2个采用锁紧式高强螺栓连接的不同形式(平/波形)腹板钢-UHPC组合梁试件，开展四点弯曲静力加载试验，研究其负弯矩区的破坏模式、承载能力、应变分布、界面滑移及裂缝分布形态。通过对受载后组合梁各构件进行拆卸与重装，评估构件损伤程度及重复利用性。基于弹、塑性理论并考虑UHPC抗拉强度，对组合梁负弯矩区开裂荷载与受弯承载力进行计算。研究结果表明：波形钢腹板组合梁负弯矩区的抗弯刚度较直腹板组合梁降低了10.7%,受弯承载力降低了32.5%,但延性提高了90%;当波形钢腹板组合梁破坏时，UHPC板的裂缝分布更均匀；构件拆卸与重装对组合梁的受力性能影响较小；理论计算的开裂荷载和受弯承载力与对应试验值相比误差小于6%,具有较高的计算精度。更多还原

【Abstract】 To improve tensile cracking resistance of concrete slab of steel-concrete composite beams in the negative moment region, and meet the needs of disassembly and replacement for bridge components, two steel-UHPC composite beams with different web forms(flat web and corrugated web) using ‘locking nut’ high-strength bolt connectors were designed. Four-point bending test was performed on the specimens to investigate the mechanic behavior in term of failure mode, loading capacity, strain distribution, interface slip and crack distribution. The components were disassembled and reinstalled after the specimens were subjected to operating load to evaluate their damage degree and reusability. A theoretical calculation of the cracking load and ultimate load of composite beam subjected to hogging moment was performed based on elastic and plastic theory and consideration of UHPC tensile strength. The experimental and analytical results indicate that the flexural stiffness of composite beam with corrugated steel web is reduced by 10.7% compared to the composite beam with flat web, and the loading capacity is reduced by 32.5%, but the ductility is improved by 90%. And the cracks distribute more uniform in UHPC slab for composite beam with corrugated web. There is only slight effect on the structural performance of composite beams due to the disassembly and reinstallation of each component. The relative error between calculated and tested cracking load and ultimate loading capacity is within 6%,showing good computational accuracy.更多还原