Re-hydration of Heat-treated <TEX>$CaO-SiO_2-H_2O$</TEX> System and Their Application under Hydrothermal Condition

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J. Korean Ceram. Soc. > Volume 31(11); 1994 > Article

Journal of the Korean Ceramic Society 1994;31(11): 1387.

열처리한 $CaO-SiO_2-H_2O$계의 수열반응과 이의 응용에 관한 연구

윤철현, 송태웅

경남대학교 무기재료공학과

Re-hydration of Heat-treated $CaO-SiO_2-H_2O$ System and Their Application under Hydrothermal Condition

ABSTRACT

Re-hydration properties of heated and ground CaO-SiO2-H2O system were studied under hydrothermal condition in order to examine the possibility of recycling ALC waste as raw materials of ALC. Powder of calcium silicate hydrates and ALC waste without heat treatment did not show further hydration while those of heat-treated at proper temperature showed re-hydration properties under hydrothermal condition. The lath-like shape of initially synthesized tobermorite was gradually turned into small debris during heating and plate-like tobermorite was crystallized during re-hydration of the heated powders. Heated and ground ALC waste could be added to natural raw mix for ALC at the ammount up to 20% with increased compressive strength and up to 30% with slightly decreased compressive strength. The optimum heating temperature of ALC for recycling was about 50$0^{circ}C$.