Overhanging Tests of Steel-Concrete Composite Girders with Different Connectors

This study investigated two overhanging 3-span composite girders to simulate the behavior of a suspension bridge. A new uplift-restricted and slip-permitted T-shape (URSP-T) connector is proposed to decrease the concrete slab tensile stress in composite girders. URSP-T connectors installed on one side of the specimen were compared with studs installed on the other side. Various elastic working conditions, ultimate sagging moment conditions, and ultimate hogging moment conditions were employed to investigate the behavior of composite girders with different connectors. The test results showed that the use of URSP-T connectors decreased the tensile stress of the concrete slab and prevented separation of the concrete slab from the steel beam. A hanger system was used to simulate hangers for suspension bridges, and it is demonstrated that girder displacement is predominantly due to cable deflection. The influence of URSP-T connectors on the mechanical properties of composite girders was investigated and design suggestions proposed. The results show that the use of URSP-T connectors increased the slippage of the interface and decreased the bending rigidity of the composite girder. Therefore, the thickness of the foamed plastics should meet the requirement of interface slippage and careful consideration of the buckling behavior of steel girders is required when URSP-T connectors are used.