Modeling of Calcium Leaching from Cement Hydrates Coupled with Micro-Pore Formation

A computational system for predicting the long-term degradation of cement hydrates due to calcium leaching is presented. The leaching of calcium ions from hardened cement hydrates is simulated as the multi-phase equilibrium of calcium in solid and liquid phases and their transport is formulated on the basis of thermodynamics. The time-dependent properties of cement hydrates associated with hydration, pore-structure development, and moisture transport are evaluated by integrating calcium leaching and statistical models of chemo-physics. The proposed model delivers reasonable predictions of calcium leaching in high-performance concrete with a low water-to-cement ratio as self-curing takes place.