A study on post-fire durability performance of concrete

Concrete structures are often exposed to fire hazards, which can significantly affect their durability and structural integrity. Post-fire durability assessment is crucial to understanding the residual strength and long-term performance of concrete after exposure to elevated temperatures. Limited research has concentrated on durability attributes, with the majority examining primarily mechanical aspects. We have thus initiated the endeavor. This study aims to evaluate the post-fire durability characteristics of concrete, focusing on strength retention, microstructural changes, and degradation mechanisms. This investigation adapted concrete compositions containing 75% recycled marble aggregate (RMA) to the mix. We exposed the prepared concrete to various temperature conditions, including 200°C, 400°C, 600°C, and 800°C. The study examined the concrete's durability features, including their acid, chloride, and carbonation resistance. This investigation revealed that the fire significantly impacted the mechanical and durability properties of the concrete. The results show that fire, in any temperature environment, significantly reduces both the mass and strength of concrete. This is true regardless of the temperature environment. Regardless of temperature, fire has a greater impact on chloride penetration in concrete. Though it was still higher than concrete mixed at ambient temperature, RMA concrete did better than the reference concrete mix. Limiting chloride penetration in the RMA concrete mixture depends critically on the alumina concentration of RMA.