Cement Hydration Microstructure Development

When Portland cement meets water, anhydrous clinker grains dissolve at their surface and precipitate calcium-silicate-hydrate (C-S-H) gel around a shrinking unreacted core — the reaction that turns fluid paste into solid stone. This simulator places a few hundred clinker grains of realistic (log-normal) size distribution in a paste volume and evolves each one through the dormant period, acceleration and deceleration stages of Avrami/JMAK boundary-nucleation-and-growth kinetics, driven by an Arrhenius equivalent-age maturity clock exactly like the one used in real concrete curing standards. Live readouts track the population-averaged degree of hydration, the instantaneous heat-release rate (hydration is strongly exothermic), and the capillary porosity predicted by Powers & Brownyard's classic volumetric model — while water/cement ratio and curing temperature sliders let you see directly why a leaner, cooler mix hydrates more slowly but ends up denser.