Elucidating the Size and Shape of Individual Clinker Phases via Raman Imaging: Impact on Cement Hydration

Portland cement, produced at 4 billion tons/year, isa key ingredientof concrete the world's most consumed material afterwater. The hydration and hardening of cement upon reaction with waterare greatly influenced by cement's chemical composition aswell as its overall particle size distribution (PSD). However, giventhat anhydrous cements are a composite mixture of 8-12 chemicallyunique phases, the physical characteristics (size and shape) of theseindividual phases have not been fully explored in the literature.Here, by utilizing Raman imaging, we report, for the first time, phase-specificPSDs and shape characteristics for all individual components in aset of 10 commercially available diverse cements. By combining thesephysical characteristics with chemical abundance, we define a composition-sizequotient parameter (CSQ), which is able to predict the72 h cumulative heat upon hydration (R (2) = 0.86)a key indicator of performance, underscoring theimportance of such phase-specific physical characteristics.