Comparative Life Cycle Assessment and Structural Performance Analysis of Eco-Friendly LC3 Cement for CO2 Reduction Compared to Portland Cement

Resumen

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 in the construction sector in Latin America. The research integrates environmental analysis, mechanical performance, and economic evaluation under a quantitative approach. The environmental impact was determined through a cradle-to-gate Life Cycle Assessment (LCA), modeled in OpenLCA using a European database, with a functional unit of 1 ton of cement.The results show emissions of 903.5 kg CO2-eq/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 mixture design under the ACI 211 method and mathematical modeling in MATLAB. At 28 days, LC3 concrete reached 32.52 MPa, exceeding OPC (29.56 MPa). A Structural-Environmental Efficiency Index (SEEI) was formulated, obtaining 0.17 MPa/kg CO2 for LC3 compared to 0.08 MPa/kg CO2 for OPC, evidencing an efficiency improvement of approximately 112%. In the economic analysis, LC3 presents a higher cost per ton compared to OPC; however, this difference responds to territorial market variations, industrial availability, transportation, and local regulations, given that LC3 is not yet produced on a generalized scale in Latin America. Overall, the results demonstrate that LC3 offers greater structural performance per unit of emission, consolidating itself as a technically viable alternative for CO2 reduction in the cement industry in the region.