Thermo-mechanical response of concrete sandwich panels reinforced with glass fiber reinforced polymer bars

The thermo-mechanical behavior of sandwich panels was experimentally investigated. The panels featured two external concrete layers reinforced with glass fiber reinforced polymer rebars (GFRP) and an internal expanded polystyrene insulation layer. These are typical for low load bearing and thermally insulated panels in façade claddings. To assess the suitability of the internal GFRP reinforcement, the heating condition was such that rebars in one concrete layer were exposed to temperatures higher than the glass transition temperature of the resins. Such extreme condition allowed verifying the retention of the mechanical behavior, in terms of deformability and load-carrying capacity, with bending tests of unheated and heated panels. As main outcome, the elevated temperature produced significant modification of the insulation layer, considerable reduction of global stiffness and load-carrying capacity, while GFRP bars were not apparently modified.