Shear properties of composite steel plate connectors for prefabricated steel–concrete composite beams

Abstract

As a critical component of prefabricated steel–concrete composite beams, ideal connectors can ensure the mechanical properties of bridges and significantly improve the efficiency of assembly construction. CSPC connector (Composite steel plate connector) with excellent load-slip curve and assembly construction efficiency was designed to realize fast and simple assembly construction. CSPC connectors require prefabricated bridge deck with no holes and low installation accuracy requirements. The results of 6 push-out specimens and 12 finite element models show that the CSPC connector exhibits an excellent load-slip curve compared to the existing connectors, and its shear stiffness and ductility coefficient are 1.03 and 1.51 times that of the stud connector, respectively. The shear stiffness and shear capacity of CSPC connectors are 0.79 times and 0.96 times the original when the grouting material age is reduced from 28 days to 3 days due to the rapid construction demand. The weakening of shear capacity is not obvious. The shear capacity of the CSPC connector comes from the connection between high-strength bolts and composite steel plates. The pressure-bearing effect of grouting material is crucial in connecting composite steel plates. Meanwhile, the composite steel plate of CSPC connector should be designed with equal thickness, a height of 30 mm and a spacing of no more than 10 mm. The recommended ratio of high-strength bolt diameter to composite steel plate thickness is 1.25. Finally, fit the load-slip relationship of CSPC connector, and propose a shear capacity formula with a deviation of less than 12 % from the test results.