钢-混凝土预制梁连接区段抗震性能试验研究

Experimental study on seismic performance of connection zone of spliced precast steel-concrete beam

为实现预制装配式混凝土框架结构的干式连接,提出一种带工字钢接头的装配式钢筋混凝土梁。通过3个不同配筋率(0.96%、1.50%、2.34%)试件的低周反复荷载试验,研究了不同弯矩系数比对其破坏形态、滞回特性、承载力、延性、承载力退化及关键部位应变的影响。结果表明,该预制混合梁在不同弯矩系数比下表现出不同的屈服顺序和破坏模式,随着弯矩系数比的减小,试件的损伤从集中在混凝土梁段到集中在钢梁段逐渐演变,滞回曲线渐趋饱满;在焊缝质量可靠的前提下,钢套筒连接区段未发生破坏,传力可靠。结合试验结果,进一步分析了该预制梁的受弯承载力计算方法和剪力传递过程。工程应用时,以钢接头屈服耗能为目标,保守建议设计弯矩系数比小于0.63,并保证钢套筒剪力传递的构造可靠。

To realize dry connections of precast reinforced concrete frames,a new type of precast reinforced concrete( RC) beams with steel connectors between RC beams and RC columns was proposed. Reversed cyclic loading tests were performed on three precast hybrid steel-concrete beams with different reinforcement ratios( i. e. 0. 96%,1. 50%,and 2. 34%),to investigate the influence of the ratio of moment coefficient γ on their failure modes,hysteretic behavior,resistance,ductility,bearing capacity degradation and strains of key positions. It is revealed that the order of yielding and the failure mode are greatly influenced by γ. With the decrease of γ,the damaged area gradually evolves from the concrete beam to the steel connector,and the hysteretic curves become increasingly full.With reliable welding,the steel sleeve connection section does not fail. Furthermore,based on the test results,a simple calculation method of moment resistance was proposed and the shear transfer mechanism was analyzed. In engineering applications,with the goal of energy dissipation of steel connectors,it is conservatively recommended that the design value of γ should be less than 0. 63,and the details of steel sleeve should be reliable for shear transmission.