Design for fire of concrete elements strengthened or reinforced with fibre-reinforced polymer: state of the art and opportunities from performance-based approaches

Recent years have seen widespread success applying fibre-reinforced polymer (FRP) materials for internal reinforcement and externally bonded strengthening of concrete structures. However, considerable reductions in mechanical and bond properties of FRP materials at elevated temperatures continue to hinder their application in buildings, where structural fire-resistance ratings are typically required. To meet currently imposed fire safety requirements, FRP materials often require supplemental fire protection insulation or thick concrete cover to maintain their temperature below an assumed (though not currently well-defined) "critical" value during an assumed standard fire exposure. Such requirements are based on a definition of structural fire resistance that is rooted in a prescriptive framework and that fails to take advantage of the state of the art in performance-based structural design for fire safety. This paper is intended to present a summary of the state of the art in this area and also to demonstrate clear opportunities for internal FRP reinforcement and external FRP strengthening of concrete elements that may arise from taking a performance-based fire safety design approach.