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.