Effect of aragonite aspect ratio on the hydration behavior of cementitious materials

The three polymorphs of calcium carbonate (CaCO₃) affect cement hydration differently. Aragonite’s needle-like shape provides extra nucleation sites and accelerates hydration, but the effect of its aspect ratio is still unclear. This study investigates the influence of aragonite with different aspect ratios on the hydration behavior of cementitious materials. Aragonite with different aspect ratios was synthesized under laboratory conditions by adjusting solution concentrations and reaction parameters. The morphology and phase composition of the synthesized aragonite were characterized using electron microscopy (SEM) and X-ray diffraction (XRD). The synthesized aragonite particles were used to replace 5% and 10% of OPC by weight to evaluate their effects on hydration.