Double Scale Model of the Aging Creep of Low Density Hydrates of Cement Paste

The creep response measured on a test at 3 months cannot be directly transposed to a structural calculation for a load at 3 years. It is also excluded to wait several years to perform a creep test on a specimen. To develop a model of material behavior incorporating aging creep, given the multi-scale and multi-physics nature of concrete, the micro-mechanical approach is attractive. The modeling part of the paper aims to estimate the aging viscoelastic behavior of cement paste from information on the chemical evolutions, extending an already developed approach to an evolving cement paste morphological model. These micromechanical models are derived semianalytically. We discuss the suitability of the self-consistent homogenization scheme to describe the setting phase of cement paste. This approach helps to check the applicability of the tools. In parallel, an experimental campaign is carried out to characterize the aging behavior at the cement paste scale.