Abstract
Abstract
This study highlights the intrinsic linkage between sustainability and fire resistance in hardened cement paste design by demonstrating that reductions in clinker content through the use of supplementary cementitious materials simultaneously influence environmental performance and post-fire mechanical behaviour. While the incorporation of supplementary materials effectively lowers the carbon footprint of concrete by reducing CO₂ emissions associated with cement production, it also alters the residual mechanical properties following elevated temperature exposure. The results indicate that higher clinker contents, which are associated with increased CO₂ emissions, do not translate into improved fire resistance; on the contrary, mixtures with reduced supplementary cementitious material (SCM) content exhibit a pronounced loss in residual compressive and flexural tensile strength after exposure to 500 and 800 °C. These findings confirm that sustainability-oriented mix design strategies can be aligned with fire performance requirements, provided that the type and dosage of supplementary materials are carefully optimised. Consequently, the study underscores that environmental sustainability and structural fire safety should not be treated as competing objectives, but rather as interdependent design parameters within performance-based concrete engineering.