ABSTRACT
A demountable perforated steel-tube shear connector is proposed to satisfy the accelerated assembly construction of precast steel–concrete composite bridges. Push-out tests using different parameters, including the wall thickness of the steel tube, height and width of the steel strips in a perforated plate, were carried out to investigate the shear strength, shear stiffness, failure modes, and relative slip characteristics of demountable perforated square steel-tube shear connectors. Based on push-out tests, efficient finite-element (FE) models were established considering the nonlinear behavior of materials and interface between steel and concrete, and validated through the compassion of test results. In addition, the shear performance between a square and a circular steel tube connector with the same thickness, perforated shape, and steel weight was compared using the verified FE models. The experimental and FE analytical results demonstrate that the demountable perforated steel-tube shear connectors have not only the equivalent shear strength of perforated rib connectors, but also possess better ductility than that of welded stud connectors. The shear strength and stiffness can be improved by increasing the wall thickness of the steel tube. The perforated shape slightly affected the shear stiffness but largely affected the shear strength. The square and circular steel-tube connectors have almost the same shear-yield strength. However, the square steel-tube connector has higher ultimate shear strength, whereas the circular steel-tube connector exhibits better ductility. All the results can provide a theoretical basis for the design of connector for steel-concrete composite bridge by accelerated assembly construction.
