Flexural performance of mortise-tenon wet joints in prefabricated ribbed beam bridges

In this study, the influence of mortise-tenon joint structures on the cracking performance of wet joint interfaces in prefabricated reinforced concrete ribbed beam bridges was evaluated by experimentally investigating four specimens involving different joint structures and theoretically analyzing one specimen with no joint structure. The results revealed that mortise-tenon joint structures exhibited superior crack resistance compared to non-jointed structures, vertical, inclined, and V-shaped joints. In particular, the mortise-tenon joint specimen was observed to maintain excellent deflection shape during the failure stage, exhibit abundant development in the deflection curve, and demonstrate optimum stiffness among all joint specimens. Its cracking load was consistent with that of the non-jointed specimen and 49% higher than the cracking loads of ordinary vertical joint specimens. The tenon structure exhibited good mechanical locking performance at the joint, thereby effectively limiting joint interface cracking. The tenon root was the weakest component of the tenon-tenon joint structure. The short-term stiffness degeneration coefficient of the mortise-tenon joint specimen was 0.952. The findings indicated that the application of Chinese traditional mortise-tenon wood joint structure to the deck of a ribbed beam bridge is feasible. The conclusions of this study are expected to serve as a reference for the future design of wet joints in prefabricated ribbed beam bridges.