Figure 1
From: Multiscale understanding of tricalcium silicate hydration reactions
Schematic understanding of the alite hydration reaction at different length scales. (Top) Hydration reaction of tricalcium silicate at the microscale. (a1) SEM microphotograph for C3S_21 µm. (a2) SEM microphotograph for C3S_3 µm. (b) SEM microphotograph for C3S_21 µm_080 paste showing a homogeneous portlandite plate microparticle, voids arising from capillary water, and three agglomerates of heterogeneous C-S-H gel. (c) Enlarged view of one C-S-H gel region in (b). (d) TEM microphotograph of C3S_3 µm_080_arrested:16d showing interspersed foil-like C-S-H nanoparticles at the mesoscale. (e) Schematic representation of the C-S-H colloidal nanoparticles of clinotobermorite (blue) and monolayer Ca(OH)2 (orange) generating the small gel pores (SGP) and large gel pores (LGP) of Jennings’s model (25). (f) Schematic representation of a single C-S-H nanoglobule composed by defective clinotobermorite and two monolayers of Ca(OH)2 at the nanoscale. (Bottom) Hydration reaction of tricalcium silicate at the nanoscale highlighting the three main components of colloidal C-S-H nanocomposite: nanocrystalline clinotobermorite, amorphous (monolayer) calcium hydroxide and gel pore water. The (approximate) densities, mass and volume percentages of the different components are also given for an overall water content of four water molecules per silicate.
