摘要

Improving mechanical performance of the negative moment regions of continuous composite beams is essential for composite beam bridges. Uplift-restricted and slip-permitted (URSP) screw-shaped connectors can enhance the crack resistance of a concrete slab through free slip between the concrete slab and the steel beam. Furthermore, URSP screw-shaped connectors are more adaptable to the requirements of rapid construction than URSP T-shaped connectors. To investigate the slip and mechanical behavior of URSP screw-shaped connectors, nine push-out tests with various parameters were conducted. In these tests, the thickness of the foam sleeve wrapped outside the screw exerted a highly significant effect on free slip performance. A refined 3D nonlinear finite element model with the foam's constitutive model was established using ABAQUS. The stress mechanism and failure modes of the FE models were analyzed. Lastly, to estimate the slip performance of URSP screw-shaped connectors, an equation with a simple form was proposed via mechanism analysis and a regression method.