Mechanical Characterization of Fibre Reinforced Polymers Materials at High Temperature

One of the greatest impediments to using fibre reinforced polymer (FRP) composites in buildings and parking garages is their susceptibility to degradation when exposed to elevated temperatures and the limited knowledge on the thermal and mechanical properties of these composites at such temperatures. Glass FRP (GFRP) tensile coupons and single lap-splice coupons were tested in tension to study the mechanical properties under steady-state and transient thermal conditions. Tests were conducted at a range of temperatures between room temperature and +200°C. In terms of tensile strength, approximately half of the strength of the FRP was lost near the glass transition temperature of the epoxy resin matrix. However, 40% of the room temperature strength of the GFRP was still retained at 200°C. The lap-splice tests showed that the FRP-to-FRP bond strength was affected even more by high temperature exposure with 90% loss in lap-splice near the glass transition temperature. An analytical model is also presented in this paper characterizing the mechanical properties at elevated temperature, which in turn will be used in numerical fire endurance models developed by the authors.