Modular GFRP web flange sandwich assemblies in fire

Glass fibre reinforced polymer (GFRP) composites have exhibited favourable properties such as light weight, high strength and corrosion resistance. Modular GFRP sandwich structures, consisting of standard pultruded GFRP box profiles incorporated between two GFRP plates, can further provide improved stiffness at the structural level by increasing sectional inertial moment compensating for the low material elastic modulus. However, certain fire insulation performance is required for such structures used in building construction. This paper presents a fire experimental study on the modular GFRP sandwich structures lined with different fire resistant panels as passive fire protection. Adhesively bonded GFRP sandwiches were prepared first and then three types of fire resistant panels were respectively assembled on the lower face sheet of GFRP sandwiches. The built-up structures were exposed to the ISO 834 standard fire curve. The thermal response of specimens were measured and comparatively evaluated and the effects of fire resistant panels on the fire insulation performance of such GFRP sandwich structures were investigated. It was found that the specimens assembled with glass magnesium board showed the most superior insulation performance, with the highest temperature at the outer face of upper flat panel (i.e. the fire unexposed surface) no more than 120°C after 90 min of fire exposure.