Evolution of C‐S‐H in lime mortars with nanoparticles: Nanostructural analysis of afwillite growth mechanisms by HRTEM

This work studies the formation of calcium–silicate–hydrates (C–S–H) in lime mortars prepared with additions nano-Ca(OH)2 and nano-SiO2 at 23.3°C. Mineral identification was carried out by X-ray diffraction after 10, 30, 90, 120 days curing. The nanoscale study starts from generation amorphous phases until development crystalline phases. Observations binder mortar made transmission electron microscopy (low magnification high resolution TEM) 30 110 curing showed two types C–S–H different degrees crystallinity depending on time. short-range order globular visible days. evolved into lamellar phase corresponds to known as afwillite (Ca3(SiO3OH)2·2H2O), first reported affect cement concrete's mechanical hydration properties. It appears isolated fibers, growing epitaxially along edges calcite (product carbonation Ca(OH)2), advancing inward aided atomic defects (grain boundaries, stacking faults). In addition, high-resolution tools simulation confirmed a monoclinic symmetry for crystals. These results contribute analyzing presence crystalline/amorphous mortars, providing information structure its possible effects materials.