Comparative life cycle assessment and structural performance of LC3 eco-friendly cement as a CO2 reduction alternative to Portland cement

Adelis Puma Pumachara M.; Kristell Melany Mejia Mamani N.; Valentina Puma Quispe C.; Lucia Llanos Portillo D. · Proceedings of the LACCEI international Multi-conference for Engineering, Education and Technology (2026) · DOI: 10.18687/laccei2026.1.1.2661

Resumen

In countries such as Brazil, Chile, and Peru, the expansion and sustained increase in global infrastructure demand continue to maintain a strong dependence on cementitious systems with a high clinker factor, representing a significant share of industrial CO2 emissions associated with production. This study develops a comparative evaluation between Ordinary Portland Cement (OPC) Type I and the ternary Limestone Calcined Clay Cement (LC3) system as a decarbonization strategy for the construction sector in Latin America. The research integrates environmental analysis, mechanical performance, and economic assessment under a quantitative approach. The environmental impact was determined through a Life Cycle Assessment (LCA) in the cradle-to-gate phase, conveniently modeled in OpenLCA for a functional unit of 1 ton of cement. Due to the limited availability of standardized regional inventories, the modeling was aligned with a European database to preserve methodological consistency and comparability between scenarios. The results show emissions of 903.5 kg CO2eq/t for OPC and 513.5 kg CO2-eq/t for LC3, representing an approximate 43% reduction mainly associated with the decrease in clinker content to 50%. Mechanical performance was evaluated through mix design under the American Concrete Institute (ACI) 211 method, and the input data were mathematically modeled in MATLAB. The comparison demonstrates that, at 28 days, concrete produced with LC3 achieved 32.52 MPa, exceeding the 29.56 MPa obtained for OPC. A Structural-Environmental Efficiency Index (SEEI) of 0.17 MPa/kg CO2 was formulated for LC3, compared to 0.08 MPa/kg CO2 for OPC, evidencing an efficiency improvement of approximately 112%. Although LC3 presented a higher estimated cost of US$264/t of cement compared to OPC (US$150/t of cement), the heterogeneous variation of US$114/t is mainly attributable to market conditions, industrial availability, transportation factors, and local regulatory frameworks related to the lack of widespread LC3 production in Latin America. Overall, the results demonstrate that LC3 provides greater structural performance per unit of emission, consolidating its position as a technically viable alternative for CO2 reduction in the cement industry across the region.

Instituciones: Universidad Tecnológica del Perú