Abstract

Adhesive bonding is a widely used joining technique across various industries and is particularly common in composite structures within the construction sector, especially for the repair and strengthening of existing infrastructure. Extensive research has been conducted to understand the behaviour of fibre-reinforced polymer (FRP) to concrete and FRP to steel bonded joints, leading to well-established design methodologies for such interfaces in civil engineering applications.

Previous studies have shown that bonded interfaces are subjected to complex stress states, and numerous theoretical models—with varying levels of simplification—have been developed to predict interfacial stresses. These models, along with numerical approaches, have been used to estimate key parameters governing the performance and failure of bonded joints, including debonding modes.

While there is broad consensus on several aspects such as bond strength, effective bond length, and bond–slip relationships, discrepancies remain regarding interfacial stress distributions, behaviour under cyclic loading, and response under elevated temperatures. Moreover, ongoing debate surrounds the suitability of homogenization approaches, such as traction–separation laws, in accurately capturing the behaviour of bonded interfaces.

In this talk, I will provide a critical review of existing research on FRP -to-concrete and FRP -to-steel bonded joints. The discussion will cover their behaviour under quasi-static monotonic loading, cyclic loading, and combined mechanical–thermal loading. Interfacial stress models and the appropriate use of homogenization techniques in modelling bonded interfaces will also be critically examined.