Modeling the coupled hydration–porosity–moisture transfers in mortars with organic admixtures

A model of the coupled evolution of hydration–moisture transfer processes and their influence on porosity is suggested for polymer-modified-mortars (PMM) with cellulose ether addition. This model is based on mass balance equations of each phase of the material (solid, liquid and gas), and hydration rates of cement compounds. It takes into account the effect of the cellulose ether, used as a polymer admixture, on the hydration kinetics. The model allows describing the time evolution of the water content, the porosity and the amount of anhydrous and hydrated products, which are the main input data characterizing the material properties in most durability predictive models. Simulation results were compared to the experimental ones obtained by thermogravimetric analysis (TGA) and water porosity measurements.