The Hydration of Hardenced Flyash-<TEX>$Ca(OH)_2-CaSO_4$</TEX>.<TEX>$2H_2O$</TEX> System

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J. Korean Ceram. Soc. > Volume 23(3); 1986 > Article

Journal of the Korean Ceramic Society 1986;23(3): 27.

Flyash-$Ca(OH)_2-CaSO_4$.$2H_2O$계의 수화반응

김창은, 이승헌, 이상완, 김원기

연세대학교 공과대학 요업공학과

The Hydration of Hardenced Flyash-$Ca(OH)_2-CaSO_4$.$2H_2O$ System

ABSTRACT

The hydration of flyash-$Ca(OH)_2-CaSO_4$.$2H_2O$ system was stuedied with varing mixing ratio of flyahs $Ca(OH)_2$ and caSO4.2H2O The samples were steam-cured for 1-7 days at 9$0^{circ}C$. The optimum mixing composition was flyash : Ca (OH)2=65:35 with 15% $CaSO_4$.42H_2O$ added which produced the hardened material having the best compressive strength (300kg/$cm^2$) Also the low specific gravity(1, 2) of the hardened paste suggests the possibility that it can be used as a light-weight building material. The added $CaSO_4$.42H_2O$ constituted calcium-sulfo-aluminate hydrates which activates the formation of C-S-H hy-drates. Both hydrates developed the strength of hardened paste. The amount of calcium-sulfo-aluminate hydrates was increased when the $CaSO_4$.42H_2O$ was added over 15% however the increased amount did not help the development of strength because of the individually grown calcium-sulfo-aluminate hydrates.