Static behavior of multi-stud shear connectors for steel-concrete composite bridge

Push-out tests were conducted to investigate the different behavior between single-stud and multi-stud connectors. The results show that the single-stud and multi-stud connectors have the similar stiffness, and the spacing of studs has little influence in the stiffness of multi-stud connectors. The ultimate strength of single-stud connector is about 10% larger than multi-stud connectors. When the load reaches its peak, the relative slip of single-stud connector is about 19% larger than that of multi-stud connectors. The multi-stud effect on static behavior of shear connector is negligible. Based on the push-out test results, a new expression of stud load-slip relationship was proposed. Compared to existing relationships, the new expression has a better match with the experimental values. The static behavior was studied and compared to design equations. The results show that the estimation based on Eurocode-4 agrees well with the multi-stud test results and the estimations based on AASHTO LRFD and Chinese code agree well with the single-stud test results.

► Push-out tests about single-stud and multi-stud shear connectors.
► Put forward a new expression of stud load-slip relationship.
► Comparison of test results and calculated values by the design codes.