Effects of the embedding depth on the interfacial bond performance of horizontally NSM CFRP strips to concrete structures

Horizontally NSM CFRP strip reinforcing concrete structures are a new type of reinforcing method, as they require a small groove depth compared with that of the traditional NSM strengthening method. In order to explore the effect and mechanism of the embedding depth of horizontally NSM CFRP strip on interfacial bond performance, the single shear pull-out test was used to compare and analyze the bond properties of concrete specimens reinforced with horizontally NSM CFRP strips, EB CFRP strips, and NSM CFRP strips, and explore the effect of horizontally NSM reinforcement methods. Then, the influence of the embedding depth on interface bonding was studied. Finally, the finite element software was used to establish a finite element model for nu-merical simulation to verify the test results of horizontally NSM CFRP strips. The results show that the specimens reinforced with horizontally NSM CFRP strips have better bonding capacity and interface bonding stiffness. The embedding depth of the CFRP strip affects the bond efficiency between the CFRP strip and concrete, and the interfacial bonding performance is the best when the embedding depth is 12 mm. The maximum bond capacity, strain distribution, and load-end slip curve of CFRP strip under finite element numerical simulation are in good agreement with the experimental results. This indicates that the bonding performance between the horizontally NSM CFRP strip and concrete can be analyzed by the finite element method. This provides a theoretical basis for the application of horizontally NSM CFRP strip reinforcement technology in practical engineering.