Bond behavior and shear transfer of steel section-concrete interface with studs: Testing and modeling

Abstract

The premature debonding at the steel section-concrete interface is the main cause of performance degradation for SRC structures. It is expected to improve the interfacial bond behavior using headed studs that can provide mechanical interlocking. However, the bond behavior and shear transfer mechanism of the steel section-to-concrete interface with studs has not been fully understood. For this reason, push-out tests on SRC specimens were performed in this research. The effects of the presence and the position of studs on the bond behavior were studied. Further, advanced finite element models considering both bond deterioration and mechanical action were developed to reveal the internal shear transfer mechanism during the entire loading process. Finally, a parametric study was carried out to investigate the influence of other key variables on the overall bond behavior and shear transfer of interface with studs. The results indicated that the headed studs could improve the interfacial bond resistance and shear stiffness, enhance the post-peak bond behavior, and prevent brittle failure, especially for the web-welded type. The evolution of load-slip behavior could be separated into five phases, i.e. the linear ascending, nonlinear ascending, post-peak descending, stable, and stud failure phases, as a result of the progressive deterioration of adhesion and activation of studs and friction. The behaviors and bond stress distribution in these phases were found to be affected by variations in the stud diameter, stirrup ratio, concrete strength, as well as number of stud rows.