Performance Evaluation of Concrete Mixtures with Calcined Clay and Portland Limestone Cement

Calcined clay offers a promising solution to the environmental challenges associated with traditional concrete production, which relies heavily on portland cement and significantly contributes to global carbon emissions. This study investigates the potential of calcined clay as a sustainable supplementary cementitious composite (SCM) for concrete applications, focusing on its integration into portland limestone cement (PLC) systems at 30% and 50% replacement ratios. For comparison, concrete mixtures with PLC alone, PLC with 30% reclaimed fly ash, and PLC with 50% slag—representative of conventional SCM practices—are also studied. The study evaluates fresh and hardened properties, hydration mechanisms, and environmental impacts through a comprehensive experimental program that includes particle size analysis, strength activity index, isothermal calorimetry, compressive strength testing, rapid chloride permeability, and life cycle assessment. Findings reveal that calcined clay can deliver comparable mechanical performance while enhancing durability and sustainability, positioning it as a viable material for eco-friendly concrete production.