This thesis presents a multiphase continuum-mechanical model for simulating the early-age behavior of concrete, governed by coupled moisture transport, temperature evolution and mechanical property development. A key innovation is the explicit inclusion of evaporation exchange in the mass balance, enabling direct coupling between evaporation and hydration—an interaction often neglected in porous media models. The evaporation process is calibrated using Dynamic Vapor Sorption (DVS) experiments.

The work also reassesses the commonly assumed linear relation between porosity and hydration degree. Allowing nonlinear dependencies, the model captures more complex interactions arising from varying microstructure and boundary conditions. Building on the framework of Gawin et al. (2006), a multiscale formulation links hydration to the time-dependent evolution of stiffness and strength.

The fully coupled finite element implementation accounts for nonlinear heat, moisture and mechanical interactions. Numerical validation across different concrete mixes shows very good agreement with experiments, confirming the model’s accuracy and broad applicability for predicting early-age concrete behavior.