Post-fire mechanical properties of glass-reinforced polyester composites

An investigation into changes in the mechanical properties of glass-reinforced polyester composites after exposure to intense radiant heat is presented. The tension, compression, flexure and interlaminar shear properties fell rapidly with increasing heat flux and heat-exposure time owing, mainly, to charring and delamination cracking caused by burning of the composite. Substantially higher post-fire mechanical properties were attained when the composite was protected from the radiant heat with a thermal barrier coating that delayed the onset of combustion. Analytical models for determining the post-fire tension, compression and flexure properties are presented. The potential use of the models for making preliminary predictions of reductions to the failure loads of glass-reinforced polyester composite structures on marine craft and naval ships, such as decks and bulkheads, caused by fire is discussed.