Thermal performance of modular GFRP multicellular structures assembled with fire resistant panels

Modular glass fibre reinforced polymer (GFRP) multicellular structures were formed using pultruded GFRP box sections incorporated between two GFRP flat panels by adhesive bonding. Three types of fire resistant panels, namely glass magnesium (GM) board, gypsum plaster (GP) board and lightweight calcium silicate (CS) board, were installed at the outer face of the lower GFRP flat panel using screws. The lower surfaces of the built-up specimens were then exposed to fire. The thermal responses of the GFRP multicellular specimens assembled with different fire resistant panels were measured and comparatively analysed, in association with the damage patterns observed. It was found that the fire resistant panels effectively mitigated the temperature progressions developed in the GFRP components, thereby improving the fire insulation performance of those structural assemblies. The GM board provided the best fire insulation performance, with the highest temperature at the outer face of the upper GFRP flat panel (the surface unexposed to fire) being less than 120 °C after 90 min of fire exposure. Further, the effects of cavities and end closure configurations of the multicellular assemblies on the heat transfer were evaluated and highlighted.