Experimental Study on the Capacity of UHPC-Filled Shear Key Between Adjacent Box Beams in Accelerated Bridge Construction

Prefabricated bridge systems and connection technology accelerate bridge construction and limit traffic disruption. One of these systems is adjacent precast concrete box beams which are placed side by side with small gaps, and top flanges connected with longitudinal shear joints. Since the concrete-filled joints provide transverse shear rigidity, the truckload transverse from one beam to another takes place. Clause 5.7.4 of the Canadian Highway Bridge Design Code (CHBDC) specifies an equation to determine the factored applied vertical shear at the shear key while clause 16.8.7.3 specifies an equation for interface shear transfer capacity. This paper summarizes an experimental study on actual-size shear keys that were customized for use in this bridge configuration and filled with ultra-high-performance concrete. A total of 14 shear-connected precast panels were cast and then subjected to shear loading at the shear key. Crack pattern, failure mode, and load-carrying capacity were recorded, and a comparison with CHBDC design values was discussed.