Effect of Graphite Addition on Thermal Behaviour of Metakaolin-Geopolymer Coating for Fire Protection of Steel

Abstract

Abstract Geopolymers are inorganic binders that resulted from the alkali activation of aluminosilicate powder. Usually, geopolymers possess better high-temperature resistance than Portland cement-based materials. This makes them a promising candidate for high-temperature applications as well as for fire protection coating. The geopolymers pastes have been the focus as an intumescent coating. This study emphasizes the geopolymer pastes from metakaolin and silica fume precursors with the additive of graphite powder and intumescent compounds. The coupons test was made of carbon steel plate 50mm x 50mm x 4mm. Since steel loses a major of its mechanical properties at 500°C, then the time-temperature curve for the coated-steel plates was created from fire testing, compared to the naked steel. Moreover, the visual appearance and the SEM structure were recorded. It is found that the addition of graphite to geopolymer improves the fire resistance of geopolymer but does not affect the intumescent behaviour. is found that the geopolymer paste graphite addition did not result in better fire resistance.