Degradation to the flexural strength and stiffness of glass reinforced polyester (GRP) ship panels due to fire is investigated in this paper. Large GRP panels were exposed to a kerosene fuel tray fire with an average temperature of-300°C for different times up to 10 minutes to simulate exposure to a shipboard fire. The extent of fire damage to the panels increased with exposure time and the two main types of damage were charring (due to combustion of the polyester resin matrix) and delamination cracking. The residual flexural properties of the firedamaged panels were determined at room temperature by loading to rupture in four-point bending. The flexural stiffness and strength decreased rapidly with increasing exposure time due to the spread of fire damage through the composite. Rule-of-mixtures models based on a reduced area of effective material due to the fire damage are presented for predicting the residual flexural properties of firedamaged GRP ship panels.
The low cost, light-weight, high strength and good seawater durability of glass reinforced polyester (GRP) composite makes it a popular construction material for maritime craft and offshore marine structures. GRP composites are used in a variety of boats and small ships such as yachts, power-boats, fishing trawlers, naval patrol boats and minehunting ships (Smith, 1990; Mouritz et al., 2001). GRP is used to a lesser extent on offshore drilling platforms in semi-structural components such as deck surfaces, office wails and pipes (Beckwith and Hyland, 1998). A problem with using GRP in marine structures is that the composite will ignite and burn when exposed to a high temperature fire. Compounding this problem is that large amounts of heat, smoke and fumes are released from the burning composite due to combustion of the polyester resin matrix.
