Effect of C/S Ratio on Microstructure of Calcium Silicate Hydrates Synthesised By Solution Reaction Method

In this work, the calcium silicate hydrate was synthesized efficiently using the solution reaction of calcium nitrate (Ca(NO₃)₂.4H₂O) and sodium nitrate (Na₂SiO₃.9H₂O) at the C/S ratio of (0.8,1.2,1.5). The disciplinarian of C/S ratio with the calcium silicate hydrate was analyzed by XRD, SEM, IR, NMR. The experimental results showed that it could shorten the reaction time to 5 days, reduce the influence of the CO₂ in the air on the purity and ensure the quality of products controllable, when the calcium silicate hydrate was synthesized in nitrogen environment and with the ultrasonic dispersion; the d-spacing of (002),(101) and (200) decreased, the polymerization of silica tetrahedra of calcium silicate hydrate decreased 28.7%, the microstructure of calcium silicate hydrate varied from layer to irregular congeries and became denser as the C/S ratio increased from 0.8 to 1.5. (paper)