Unlocking the Potential of Dolomite for Developing More Sustainable Cementitious Materials through Partial Calcination

Waste dolomite powder, a widely available industrial byproduct, has recently gained attention as a potential supplementary cementitious material. However, its inert reactivity challenges its potential for substantial cement replacement. This study explores the effectiveness of partially calcined dolomite (PCD) integrated with calcined clay for a high cement substitution level. A novel partial calcination method is introduced to optimize the decomposition of MgCO₃ and CaCO₃ to produce a core–shell structure with a highly reactive external CaO/MgO layer and a dense internal core of CaCO₃ and MgO. This configuration significantly enhances the formation of calcium silicate hydrate gels and carboaluminate phases, improving the overall strength of the material by over 90% at both 7 and 28 days compared to the sample with uncalcined dolomite. Additionally, the formulation of the proposed materials reduces CO₂ emission by 43% and energy consumption by 47% without sacrificing compressive strength. This innovative calcination technique broadens the application of waste dolomite in the development of sustainable cementitious materials.