Bonded Fibre Reinforced Polymer Strengthening in a Real Fire

Abstract

FRP strengthening is critically dependent upon the bonding adhesive. The adhesive used is typically an ambient cure epoxy with a glass transition temperature as low as 60ºC. This paper describes the performance of bonded FRP strengthening within real compartment fires (the Dalmarnock Fire Tests), one of which was allowed to grow past flashover. The aim of these real fire tests was to complement the laboratory-based fire tests on FRP strengthened members that are currently being undertaken at various research centres. In this study, externally bonded plate and near-surface-mounted FRP strengthening were applied to the ceiling of a concrete structure. The FRP was protected using either an intumescent coating or gypsum boards, alongside FRP that was left unprotected. The tests demonstrated the vulnerability of FRP strengthening during a real compartment fire. The glass transition temperature was rapidly exceeded in the bonding adhesive for all samples. The near-surface mounted strengthening and the gypsum board protected strengthening was in a visibly better condition after the fire.