ABSTRACT Clarifying the basic hydration mechanism of MgO–CaO clinker aggregate is an essential prerequisite for preparing hydration‐resistant aggregates. In this study, the hydration mechanism and kinetics of MgO–CaO clinker aggregate were clarified by segmenting kinetic modeling using multiple hydration models. Microstructural and phase characterization reveal that the hydration of MgO–CaO clinker aggregate is dominated by CaO hydration. The hydration kinetics of MgO–CaO clinker aggregate are governed by a dual mechanism involving chemical reaction and diffusion. The initial stage is controlled by surface reaction kinetics. As hydration proceeds, the formation and thickening of the hydrate product layer introduce diffusion resistance, leading to a transition from chemical reaction‐controlled to diffusion‐controlled kinetics. Finer particle sizes accelerate the hydration of MgO–CaO clinker aggregate, causing the rate‐controlling mechanism to transition from the dual control of internal diffusion and chemical reaction to the exclusive control of chemical reaction kinetics.
Meng et al. (Fri,) studied this question.