Multiphasic Model of Early-Stage Concrete Hydration Considering Evaporation

This study introduces a novel numerical model for early-age concrete that advances existing multiphase approaches by explicitly integrating an evaporation exchange mechanism. Calibrated using original dynamic vapor sorption experiments, the model captures the critical impact of moisture loss on hydration kinetics and mechanical property evolution—an aspect often omitted in prior porous media formulations. Building on established triphasic porous media frameworks, our approach enhances predictive accuracy by coupling evaporation-driven moisture transport with multiscale strength and stiffness development. The model is implemented in a multifield finite-element solver, enabling fully coupled heat, moisture, and mechanical simulations. Three numerical examples demonstrate its capabilities: simulation of moisture and temperature evolution, validation against benchmark data, and prediction of early-age strength and stiffness using a hydration-driven multiscale formulation. Results show excellent agreement with experiments, confirming the improved realism and robustness of the model. This work delivers a computationally efficient and experimentally grounded tool for simulating early-age concrete behavior across a range of curing conditions and mix designs.