Shear Behavior of Joints in Precast Segmental Bridges with External Prestressing Tendons Considering the Effect of Bending

Abstract

To reveal the effect of bending on the shear behavior of joints in precast concrete segmental bridges, 11 specimens with various shear span-to-depth ratios, joint types, and prestressing levels were subjected to combined shear and bending for failure. During the test, the initiation and development of critical cracks; relative slippage and opening of joints; failure processes and modes; and strains of concrete, stirrups, and external prestressing tendons were recorded. Based on the test results, a theoretical method for predicting the shear capacity of joints considering the bending effect was developed, and a detailed parameter analysis was conducted to compare the shear–bending resistance correlation curves of joints with different parameters. It was observed that, under relatively low bending moments that did not induce cracking, the shear capacity of the joint remained constant at a specific value. With a further increase in bending moment, the concrete in the tension zone started to detach, leading to a rapid decrease in the shear capacity. Increasing the initial tensioning stress of external prestressing tendons proved effective in enhancing the shear capacity of joints. The theoretical method developed to predict the shear capacity of joints, accounting for the influence of bending, demonstrated good agreement with the experimental results.