Wet-bonding is a technique of connecting fiber reinforced polymer (FRP) profile and cast-in-place concrete, which is characterized by the simultaneous hardening of concrete and adhesive. The mechanical properties of wet-bonding interface have been investigated by researchers, but none of them considers the influence of lateral confinement which is commonly present in structures. The insufficient knowledge on wet-bonding consequently hinders its application in FRP-concrete hybrid structures. To this end, this paper investigates the bond properties of wet-bonding interface in confined concrete through pullout and pushout tests. Test results indicate that the interfacial behavior of wet-bonding interface can be divided into three stages. In the first stage, the interfacial resistance comes from the chemical bond of adhesive, and the lateral confinement is hardly activated. This stage comes to an end when the interface between adhesive and concrete fails. In the second and third stage, the interfacial resistance is mainly contributed by the friction between fractured surfaces of adhesive and concrete. The relative movement of fractured surfaces which are microscopically rough induces vertical movement and then activates the lateral confinement, resulting in lateral pressure and tangential friction. The significant friction behavior further damages the FRP-adhesive interface, leading to the final delamination of adhesive from the FRP plate. Based on the above force-transfer mechanism, a bond stress-slip model depending on the lateral pressure is developed. This interfacial model is implemented into Abaqus and its effectiveness is verified by comparing with test results.
Discussion(0)
No comments yet. Be the first to comment.