Coload‐bearing capability of corroded and separated RCPs rehabilitated with ClPP alongside the mechanical behavior of the liner

Abstract Joints are the most problematic location for reinforced concrete piping (RCP) and are one of the main contributing factors to pipeline failure. The use of cured‐in‐place pipe (CIPP) technology can effectively rehabilitate joint defects, enhancing the service resilience of the pipeline. However, the coload bearing of the CIPP‐RCP composite structure after rehabilitation remains unclear, particularly in the presence of composite defects at the joints. To address this, three‐edge bearing tests were conducted on CIPP‐RCP composite structures. The effects of separated length, corrosion width, corrosion depth, and corrosion length on the coload‐bearing capability of the composite structures were analyzed. Furthermore, numerical models of the CIPP‐RCP composite structures were constructed using cohesive elements with a bilinear traction–separation response to simulate the CIPP‐RCP bonding interface. These models were validated against experimental results. The influence of separated length, corrosion width, corrosion depth, and corrosion length on the von Mises stress of the liner was further investigated. Univariate functions relating each defect parameter to the maximum von Mises stress of the liner under various simulation conditions were fitted, an equation for calculating the maximum von Mises stress of the liner pipe was derived. The test results indicate that when the separated length was less than 200 mm, the mechanical capability of the defective RCP could be restored, and the ultimate load capacity could be increased. The more severe the internal corrosion, the weaker the coload‐bearing capability of the composite structure. However, when the corrosion width expands to 150° and the corrosion length increases to 400 mm, the ultimate load of the composite structure slightly increases. Numerical results show that the maximum von Mises stress in the liner exhibited a quadratic polynomial relationship with both separated length and corrosion length, a negative exponential relationship with corrosion width, and a positive linear relationship with corrosion depth. The derived predictive equation can accurately predict the maximum von Mises stress of the liner.