Environmental assessment of cement replacement materials in cement paste systems based on previously published mechanical data

Abstract Cement-based materials are significant contributors to global CO 2 emissions, primarily due to the high cement content required for durability. This study explores the use of cement replacement materials (CRMs) such as unprocessed waste fly ash (UWFA), waste cellular concrete powder (WCCP), and waste perlite powder (WPP) to reduce the environmental impact of cement-based materials. The research assesses the compressive strength and ecological footprint of cement paste mixtures incorporating varying proportions of these CRMs. Results indicate that while higher substitution rates can reduce cement content and CO 2 emissions, they may also impact the mechanical properties of cement paste systems. Optimal replacement ratios were identified to balance strength and sustainability, with WPP achieving the most favourable environmental impact without significant loss of compressive strength. This study contributes to the development of sustainable concrete by promoting the use of waste materials and reducing the reliance on traditional cement.