Fully-scale test and analysis of fully dry-connected prefabricated steel-UHPC composite beam under hogging moments

摘要

A fully dry-connected prefabricated composite beam is proposed that satisfies the requirements for accelerated bridge construction. The fundamental prefabricated structural elements are the ultra-high-performance concrete (UHPC) panels and the main steel beams, which are connected by bolting and welding. Onsite wet construction is completely removed. To investigate the crack resistance and bending behavior of the novel fully dry-connected composite beam, two full-scale specimens were tested. The crack development, slippage between the UHPC panel and the steel beam, load-deflection response, and the strain distribution were monitored. An adequate bolting torque applied to the high-strength bolts connecting the concrete panels and the steel beam is important in guaranteeing the composite action of the composite beam. Based on tests, a numerical model was configured in ABAQUS that delivered good agreement with test results. The division of the UHPC panels and the layout of the bolts were investigated through parametric analysis. The division did not evidently change the load-deflection response, but fewer panels may result in better crack resistance. With the larger spacing between the bolts, the overall stiffness and crack resistance had evident deterioration.