hydration of the Fly Ash-CaO System in the Presence of Various Chemical Activators

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J. Korean Ceram. Soc. > Volume 35(2); 1998 > Article

Journal of the Korean Ceramic Society 1998;35(2): 185.

화학 활성화제에 의한 플라이애쉬-생석회계의 수화반응

송종택, 김재영, 류동우, 고상렬, 한경섭¹

단국대학교 재료공학과
¹한국과학기술원 세라믹스연구부

hydration of the Fly Ash-CaO System in the Presence of Various Chemical Activators

ABSTRACT

This experiment carried out in order to investigate the effect of the chemical activators for acceleration of hydration the system of Fly ash-Cao The paste was consisted of 80wt% Fly ash and 20wt% CaO with 1. 3. 5wt% of 4 activators(N{{{{ alpha _2 }}S{{{{ OMICRON _4 }}, CaC{{{{ {l }_{2 } }}, NaOH, Ca(N{{{{ OMICRON _3 {)}_{2 } }} and W/S ratio of 0.42 After curing for 1, 3, 7, 14, 28 days the paste hydration was characterized by the measurement of compressive strength XRD analysis SEM observation the combined water and the reaction amount of Ca(OH)2 determination. As a result of this ex-periment all of the system which involved Na2SO4 or NaOH had a god compressive strength. In the case of 7 days curing a system which added CaCl2 showed the highest compressive strength among all especially NaOH system showed a high increase in strength as a dosage of it increased. Hydration products were different according to activatores added. Only C-S-H was observed in NaOH system. As the reaction amount of Ca(OH)2 and combined water were increased the compressive strength increased. There were few differences in the comparision of strength between ignited loss 3.1% and loss 9.3% of fly ash.

Key words: Hydration, Fly Ash-CaO, Chemical activators, Acceleration, Compressive Strength