Design considerations for headed shear studs embedded in ultra-high performance concrete as part of a novel bridge repair method

This paper presents design parameters and considerations for headed studs embedded in UHPC as part of a novel bridge repair method. The method is developed for retrofitting of steel bridge girders with severe corrosion at the ends. In this repair method, headed shear studs are welded to the undamaged portion of the web plate at the girder end and encased with Ultra-High Performance Concrete (UHPC). The end bearing capacity is increased by transferring shear forces from the web to UHPC casts through the studs. Sixteen push-out tests were performed to evaluate design considerations prior to field implementation. The effects of a) eccentric loading, b) concrete material variations, c) clear and side cover, d) welding/surface preparation, and e) curing of UHPC on shear capacity of studs were studied. The results were used to establish design and installation recommendations for the proposed repair.