Experimental study on shear behavior of high-strength bolt connection in steel-concrete composite beam

In order to study the shear behavior of high strength bolt connection in steel-concrete composite beam,a total of eleven push-out specimens were tested. The tests were developed to investigate the failure modes, load-slip curves and the shear capacity of bolt connectors by changing parameters including bolt pretension, bolt diameter, diameter of prefabricated holes in steel and concrete, and compressive strength of concrete. Two failure modes were observed in the experiments: the compression damage of concrete around the bolt and the bending shear failure of the bolt at the interface between the steel beam and the concrete. The high-strength bolts were subjected to combined action of shear force, bending moment and tensile force. The bolt diameter and the compressive strength of concrete are the main parameters affecting the shear bearing capacity of bolted connector. The shear capacity of bolted connection increases with the diameter of the bolt and compressive strength of concrete. The change in pretension of high-strength bolt connection has significant effect on the initial slip load, but has less effect on the shear capacity. © 2019, Editorial Office of Journal of Building Structures. All right reserved.