Synthesis and performance of intumescent alkali-activated rice husk ash for fire-resistant applications

This study investigates intumescent alkali-activated rice husk ash (RHA) as an alternative to conventional fire-resistant building systems such as aerated concrete panels. The alkali-activation of RHA forms a polymerised sodium silicate gel. Its intumescence is caused by simultaneous softening and the evaporation of water. The softening behaviour was observed with the glass transition of the material occurring at 120 ?degrees C. Meanwhile, physically adsorbed water and hydroxyl groups vapourising after the onset of glass transition act as the blowing agent to form the porous structure. The fire resistance of the intumescent alkali-activated RHA panel was assessed through its insulation capacity at elevated temperatures up to 1000 ?degrees C. It was also compared against conventional aerated fly ash-based geopolymer panels with similar weight per unit area at two different densities (600 kg/m(3) and 1000 kg/m(3)). The alkali-activated RHA panel, despite being 60% smaller in thickness, showed a better insulation capacity than the aerated geopolymers.

Automated summary

This study investigates the potential of intumescent alkali-activated rice husk ash as an alternative fire-resistant building material. The results show that the alkali-activated RHA demonstrates better insulation capacity at high temperatures compared to conventional aerated fly ash-based geopolymer materials.