In the present study, to improve the properties of Mg-based hydraulic lime prepared by using Korean low-grade dolomite, inorganic admixtures such as silica fume and gypsum were mixed with the dolomite, and the properties of the resulting hydraulic lime were evaluated depending on the amount of admixtures and the curing time. The silica fume mixing ratio was 10%, 20%, and 30%, and the gypsum mixing ratio was 0% and 3%. The samples, prepared as a paste and a mortar, were cured at a temperature of 20 oC and a humidity of 95% for 3, 7, 28, 56, and 91 days. The hydration characteristics and the physical properties of the samples at each curing time were evaluated. The experimental results showed an increase of C-SH production was increased with increasing silica fume mixing ratio and curing time. The quantity of C-S-H produced was greater in the samples prepared without mixing gypsum. The measurement of the compressive strength showed that the strength was decreased at a silica fume mixing ratio higher than a certain level regardless of the mixing of gypsum. The strength was less decreased in the samples prepared by mixing gypsum. The best properties were found in the sample prepared by mixing 20% silica fume and 3% gypsum.

Keywords: Dolomitic low grade limestone, Mg-base hydraulic lime, Silica fume, Gypsum, Hydration