Thermodynamic modeling and life cycle assessment of limestone calcined clay cements

Abstract

To meet the net-zero CO₂ goal by 2050, low-carbon construction materials like limestone calcined clay cement (LC3), which replaces a large portion of clinker with calcined clay and limestone, are essential. This study used thermodynamic modeling and life cycle assessment to evaluate a range of LC3 formulations with clinker content from 65% to 35%. Results show aluminate-CaCO₃ interaction forms stable carboaluminate phases, leading to a denser microstructure. While lower clinker content leads to a decrease in pH and solid volume, the LC3-50 mixture achieved the optimal balance between hydration product stability and material efficiency. LCA confirms that reduced clinker content significantly lowers environmental impacts across all indicators, most notably achieving a 32.92% reduction in global warming potential and a 40.78% reduction in ozone depletion potential. These findings offer a scientific basis for optimizing LC3 mixtures and promoting its use as a sustainable building material.