Evaluating the Environmental Impacts and Social Risks of Limestone Calcined Clay Cement (LC3) Mortars

Cement production significantly contributes to global CO2 emissions. Limestone Calcined Clay Cement (LC3)—a mixture of limestone, calcined clay, cement clinker, and gypsum—offers a promising alternative by significantly reducing clinker contents without compromising mechanical performance. This study assesses the environmental and social hotspots of various LC3 mortars produced in Germany, a context not yet explored in previous research. While prior studies have mostly focused on LC3 in concrete applications and in low- to middle-income countries, this is the first to evaluate LC3-based mortar in a high-income, highly industrialized context using both Life Cycle Assessment (LCA) and Social Risk Assessment (SRA) to determine the main environmental and social drivers of this material. The LCA revealed that LC3 mixtures achieve substantial reductions in key impact categories compared to conventional Ordinary Portland Cement (OPC) mixes, including Climate Change (up to 42.6% reduction) and Particulate Matter (up to 15.8% reduction). The SRA highlights significant social risks related to corruption, fair competition, and workers’ rights, including fair wages, discrimination, and safe working conditions. This study underscores LC3 as a promising sustainable solution in cement applications while emphasizing the importance of region-specific assessments to address unique environmental and social considerations.