Post-fire mechanical properties of marine polymer composites

Changes to the tensile and flexure properties of marine-grade glass-reinfor ced polyester, vinyl ester and resole phenolic composites after exposure to radiant heat are investigated. The properties were determined at room temp erature after the composites had been exposed to heat fluxes of 25-100 kW/m (2) for 325 s or to a heat flux of 50 kW/m(2) for increasing times up to 18 00 s. The stiffness and failure load of all three composites decreased rapi dly with increasing heat flux or time due mainly to the thermal degradation of the resin matrix. The post-fire tension and flexure properties of the r esole phenolic composite were similar to the properties of the other compos ites, despite its superior fire resistance. Models are presented for determ ining the post-fire mechanical propel-ties of fire-damaged composites, and are used to estimate the reductions in failure load of composite ship mater ials caused by fire. (C) 2000 Elsevier Science Ltd. All rights reserved.