A thermo-mechanical interface model for simulating the bond behaviour of FRP strips glued to concrete substrates exposed to elevated temperature

•The bond behaviour of FRP laminates glued to concrete substrates exposed to high temperature is modelled.•A theoretical model is formulated within the framework of Fracture Mechanics and Plasticity.•A temperature-based softening formulation is proposed.•The general formulation of an elasto-thermo-plastic model featuring fracture energy-based softening and thermal damage is proposed.

This paper proposes a model aimed at simulating the bond behaviour of Fiber Reinforced Polymer (FRP) laminates glued to concrete substrates and exposed to high temperature. Based on a previous model already formulated by one of the authors and available in the scientific literature, the present paper proposes a theoretical model formulated within the general framework of Fracture Mechanics and Plasticity-based concepts. Particularly, the aforementioned model is extended herein to consider the thermal effects, through a temperature-based scaling function affecting the strength parameters and softening rules which define the failure surface and the post-cracking response of FRP-concrete joints. The mechanical soundness of the proposed model is demonstrated by the very good agreement between some experimental results taken from the scientific literature on FRP-to-concrete systems tested in pull-out loading at normal and elevated temperature and the corresponding theoretical simulations.