High volume fly ash and basalt-polypropylene fibres as performance enhancers of novel fire-resistant fibre reinforced cementitious composites

This study attempts to address the fire resistance of fibre reinforced cementitious composite (FRCC) while considering sustainability. Sustainable FRCC mixes were developed by varying the contents of silica fume and high-volume fly ash (up to 60% by wt.), along with a hybrid combination of basalt and polypropylene fibres. The FRCC was exposed to temperatures up to 800 °C, and its appearance, mass loss, and compressive properties were analysed. Exceptional performance in terms of resistance to cracking and strength retention was observed. The relative residual compressive strength of one of flyash based mixes was found to be 93.46%, 117.48%, 102.03% and 38.48% between 200 and 800 °C. Also, fly ash enhanced the mass retention properties especially with higher replacement levels and at higher temperatures. The influence of temperature on hydration products in the system has been explained using scanning electron microscope, X-ray diffraction, and thermogravimetric analysis. Furthermore, the improvement in thermal performance is demonstrated as a novel incentive for addition of fly ash in high volumes.