Experimental study on shear performance of bond-tooth dry joints in prestressed assembled concrete beams

Abstract

Assembled concrete bridges have the advantages of scale, high quality, and low requirements for the surrounding environment. However, assembled concrete beam splice joints have problems such as complex assembly and high transportation requirements. For this reason, this study proposes a large key-tooth shear key to solve the problems of low shear bearing capacity and complex collocation of conventional concrete shear keys. To study the shear capacity of the large key-tooth shear key, six large key-tooth shear key specimens were designed and tested in direct shear under monotonic vertical load. From the structure of large key-tooth concrete shear keys, the analysis focuses on the damage modes and damage criteria of large key-tooth shear keys. The effects of shear key height, key tooth depth to height ratio, number of key teeth, and concrete strength on the shear performance of assembled bridge shear keys are investigated, and the load-carrying capacity variation law of large key tooth concrete shear keys under different working conditions is explored. In addition, the parameters of the nonlinear finite element concrete material principal model and steel principal model were used to perform finite element analysis of precast assembled concrete dry joint shear keys, and the damage modes of shear keys under various working conditions were explored. Multiple linear regression equations were established to evaluate the load-carrying capacity of concrete shear keys with large key teeth and to obtain the weak surface of the structure. The three-dimensional finite element model established can well simulate the structure of large bond-tooth shear keys and more accurately assess the damaged state of shear keys for application in actual structures and design of more reasonably stressed members.