Etude du couplage thermochimique au sein de matrices cimentaires en cours d'hydratation

ABSTRACT At very early age, cementitious systems can undergo thermal variations due to the double exothermic and thermoactivated property of cement hydration. The parameters of this thermochemical coupling (thermal conductivity, specific heat capacity, apparent activation energy and chemical affinity) have been identified from the literature and measured on cement pastes during the first 24 hours of hydration. They are then used in a 2D numerical model for the computing of hydration degree and temperature field of hardening cement-based materials. The aim is to quantify the effect of the thermophysical parameter values on the prediction of the material's behaviour at very early age. The sensitivity study shows that the influence of thermal property values is particularly significant in the case of temperature field computation.