Flexural behaviour analysis of wet joint of precast bridge deck with UHPC functional gradient

To optimize the wet joint structure of a precast bridge deck and make effective use of ultrahigh-performance concrete (UHPC), five specimens of the prefabricated UHPC functional gradient wet joint plate (UFGWJP) and one normal concrete prefabricated wet joint plate were tested by four-point bending, and their failure modes, bearing capacity, deformation performance, and strain distribution were analysed. The results show that the failure mode of all joint plates was bending failure, and the initial cracking position was basically at the interface between the joint and the precast slab. The excellent mechanical properties of UHPC enhance the bonding performance between the joint and the precast plate interface and significantly improve the cracking load. With an increase in the thickness ratio of UHPC and the flexural toughness ratio of UHPC/normal concrete (NC), the bearing capacity and deformation performance of the joint plate gradually increase. Furthermore, the wet joint of a prefabricated bridge deck with a functional gradient can be designed and fabricated, and the structural optimization of the prefabricated bridge deck wet joints is proven successful by tests.