Effect of high temperature on the microstructure and residual strength of green flowable sand concrete produced with granite waste and seashell powder

The durability of concrete structures and human safety can be seriously affected by fire. The present investigation was conducted to determine the fire resistance of flowable sand concrete (FSC) prepared using seashell powder (SSP) cement substitute (5, 10, and 15% by weight) combined with granite waste a replacement for natural fine aggregate (10, 20, 30, and 40% by volume). For this purpose, the changes in weight, compressive strength, and microstructure properties of hardened FSCs were measured before and after exposure to different high temperatures of 200 °C, 400 °C, 600 °C, and 800 °C. The results showed that the use of up to 40% GW as a replacement for fine aggregate and 10% SSP as a cement replacement could be positively incorporated in the production of SSP-blended FSC, where failure due to fire is a problem.