Y-type perfobond rib shear connectors subjected to fatigue loading on highway bridges

This study evaluated the structural performance of Y-type perfobond rib shear connectors under cyclic loading; the plastic slip, stiffness ratio, and residual strength were also measured. Cyclic loading tests were conducted on each specimen for 650,000 cycles, and the specimen with the maximum plastic slip was subjected to 1300,000 cycles to investigate the long-term behavior. After the cyclic loading test, push-out tests were conducted to evaluate the residual strength. Under repeated loading, the Y-type perfobond rib shear connectors experienced a slightly larger permanent plastic slip than the puzzle-shaped dowels and stud shear connectors in the early stage. However, this maintained the slip level between the other shear connections after 500,000 cycles. The residual strength and stiffness ratio of the Y-type perfobond rib shear connectors remained unchanged even if the system experienced an initial plastic slip. To evaluate the applicability of the Y-type perfobond rib shear connector to highway bridges, the structural performances of plate and steel box girders using these connectors were analyzed numerically. The numerical simulation results for the bridge examples showed that the additional deflections and bending stresses due to the early-stage plastic slip were negligible.