Experimental and numerical investigations on shear performance of key tooth joints of precast concrete segmental bridge under repeated loading

•Experimental and numerical investigations are conducted on the behavior of adhesive KTJ under repeated loading.•Failure modes for epoxied KTJ specimens of different configurations under repeated loading are analyzed.•Ultimate load-bearing capacity and the stiffness of the KTJ specimen under repeated loading are significantly reduced compared to those of specimen under monotonic loading.•Effects of both reinforcement in single large key and fibers in concrete on the cyclic behavior of KTJ specimens are analyzed.•The finite element modes (FEM) of KTJ specimens under repeated loading are developed and are in good agreement with the experimental results. Precast concrete segmental bridge (PCSB) has developed rapidly because of its advantages of fast construction speed, little environmental impact, easy quality control, and low cost. The key tooth joint (KTJ) is the critical connection part of PCSB. Limited research on performance of KTJ under repeated loading is available. This study includes experimental and numerical investigations on the behavior of adhesive KTJ under repeated loading. Five scenarios of KTJ with different configurations, including geometries of keys, number of keys, reinforcement in key, and steel fibers in concrete, are included. It is found that KTJ with small keys and KTJ with a single large key present similar behavior when the contact areas are kept the same, and the behavior of the large key is stiffer. Compared to monotonic loading, the load-bearing capacity and stiffness of KTJ are significantly reduced under repeated loading due to the damage accumulation in concrete. Adding steel fibers (in concrete) can evidently enhance the ductility of KTJ and adding reinforcement (in large key) can reduce the damage accumulation effects. The developed finite element models of KTJ under repeated loading agree well with the experimental results regarding the cracking development, load–displacement behavior, and load carrying capacity.