拉力作用下部分外包钢-混凝土组合构件受剪性能试验研究

Shear behavior of partially encased steel-concrete composite specimens under tension

为了研究型钢与部分外包混凝土的在拉力作用下的纵向剪力传递性能,对6个部分外包钢-混凝土组合构件进行了轴拉试验,对其破坏形态和荷载-滑移曲线进行了分析。试验中主要考虑了型钢与腹部混凝土的黏结长度、混凝土强度、栓钉连接件数量等影响因素。研究结果表明:部分外包钢-混凝土组合构件破坏形态主要表现为黏结破坏、混凝土压碎和栓钉剪断;轴拉试验和推出试验中无栓钉连接的部分外包型钢混凝土组合构件的黏结力均随着型钢与混凝土间的黏结长度的增加而增大;对于无栓钉和有栓钉组试件,轴拉试验和推出试验中型钢与混凝土间的受剪承载力均随着混凝土抗拉强度的增加而增大,且近似成线性关系;部分外包钢-混凝土组合构件的受剪承载力随栓钉数量的增加而增大;相较无栓钉组试件,采用2根栓钉连接和4根栓钉连接的轴拉试件,其受剪承载力分别可提高近100%和250%。

In order to study the longitudinal shear transfer behavior between the profile steel and the concrete encasing the steel web under tension,the failure modes and the load-slip curves were analyzed by the axial tension tests of six partially encased steel-concrete composite specimens. The parameters studied mainly included the bond length between the profile steel and the concrete,the concrete strength,as well as the number of stud connectors. The experimental results indicate that the failure of the partially encased steel-concrete composite specimens is mainly caused by concrete crushing,bond failure and shear failure of the stud. Under axial tension test and push-out test,the bond strength of specimens with no shear stud increases with the increasing of the bonding length between the profile steel and the concrete. The shear capacity of the specimens increases in an approximately linear relationship with the increasing of the tensile strength of the concrete in axial tension tests and push-out tests. The shear capacity of the specimens increases with the increasing of the number of studs. Compared with specimens without shear stud,the shear capacity of the specimens with two studs and four studs was increased by nearly 100% and 250%,respectively.