Résumé
Strength and other mechanical properties of cement paste and concrete rely upon the formation of calcium-silicate-hydrates (C-S-H) during cement hydration. Despite the potential for technological transformation, controlling the structure and properties of C-S-H phase is still a challenge, due to the complexity of this hydration product and of the mechanisms that drive its precipitation from ionic solution upon dissolution of cement grains in water. Departing from traditional models that are mostly focused on length-scales above the micrometer, molecular models have recently addressed the nanometer-scale structure and properties of C-S-H. However, small angle neutron scattering, electron-microscopy imaging, and mechanical nano-indentation experiments, all suggest that an even more important role is played by the meso-scale organization of the C-S-H structure that extends over hundreds of nanometers. New quantitative models are needed to address this unexplored meso-scale, elucidate the experimental observations, and complete the understanding of the multi-scale structure of cement paste. Here we present a novel description of the C-S-H meso-structure that offers an opportunity to translate results from the fundamental scales to the macro-scale of engineering properties.
