Thermal resilience and empirical modeling for residual properties of concrete with silica fume and waste glass powder

Fire-damaged concrete structures frequently lose their strength and durability permanently, which raises serious safety issues. This study examines the use of silica fume (SF) and waste glass powder (GP) as sustainable partial substitutes for cement to enhance the performance of concrete following fire exposure. Concrete mixtures with different amounts of silica fume (SF) and glass powder (GP) ranging from 0% to 25% were tested at higher temperatures from 200 °C to 600 °C. The evaluation encompassed properties like compressive strength, water absorption, mass loss, static and dynamic modulus of elasticity, and ultrasonic pulse velocity. Furthermore, samples were subjected to sodium chloride and magnesium sulphate solutions for 90 days to evaluate chemical resistance. The mixture of 10% SF and 10% GP demonstrated optimal strength at ambient temperature, although it exhibited diminished performance at elevated temperatures. In comparison, the 20% SF and 20% GP mix had lower strength at first but kept its strength similar to the control mix when exposed to high temperatures, making it a good choice for concrete buildings in tough conditions. Microstructural research demonstrated that sustainable cement-based mixtures substantially decreased mass loss when subjected to heat, signifying improved durability. Furthermore, correlations between residual compressive strength and other attributes facilitated the formulation of empirical models for assessing concrete performance post-fire exposure.