Multiscale estimation of the thermal properties of cement-based materials at early-age

International audienceThe prediction of the thermal response of concrete structures depends on the adequate determination of the thermal properties of concrete. Especially at early-age, these properties depend on the evolution of the microstructure and the multiscale character of cementbased materials. In this paper, heat capacity, thermal conductivity and coefficient of thermal expansion (CTE) are estimated by means of analytical homogenization techniques from the composition of the material. Mori-Tanaka and Generalized Self-consistent schemes are combined to represent cement paste, interface transition zone (ITZ), mortar and concrete microstructures. The evolution of the clinker and hydrates phases are accounted for at the cement paste scale. At the mortar scale, the ITZ is considered. Finally, concrete effective properties are obtained. CTE is estimated within an ageing linear viscoelasticity framework. The estimations are compared to the final values obtained experimentally in previous tests