CHARACTERISTICS OF LIME-SILICA FUME MIXTURES

The hydration of two calcium hydroxide-silica fume mixtures was studie d at 25 degrees C. The mixtures were prepared at lime/silica molar rat ios of 1.0 and 1.7. The free lime, free silica and chemically combined water contents were determined after various periods of hydration (0. 5 h - 90 days). Thus, the molar ratios CaO/SiO2 and H2O/SiO2 molar in the calcium silicate hydrates (CS-H) formed could be derived. The hydr ates formed were identified by using differential thermal analysis. Th e mechanism of the hydration-gardening thermal analysis. The mechanism of the hydration-hardening reaction between lime and silica fumes was suggested. The changes in the molar ratios CaO/SiO2 and H2O/SiO2 in t he C-S-H formed with the time of hydration were found to follow the sa me trends as observed during the hydration course for the suggested me chanism.