Abstract
The model of C3A-Gypsum hydration model is modified for considering existence of solid-solution of monosulfate and C-A-H in AFm phase, formation of C-A-H on the C3A particle surface, and diffuse double layer of C-A-H. In the hydration reaction, the phase equilibrium and the surface complexation reactions were assumed to be used in the model. For W/S＝2.0, the hydration reaction proceeded by the phase of equilibrium. During early age of hydration for W/S＝0.6, phase equilibrium and surface complexation caused the hydration process. At later age of hydration, not only the reaction between Ettringite and unhydrate but also Ettringite and C-A-H continuously occurred producing the AFm phase.
