• Journal of the Korean GEO-environmental Society
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• v.12 no.10
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• pp.73-82
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• 2011

Coal ash of industial by-products was not recycled about 30% in total emissions. Moreover, it caused environmental pollution as well as wasted unnecessary expenses and time. Currently, fly ash(FA) is recycled as construction material however ponded ash(PA) is mostly buried. Lightweight foamed Controlled Low-Strength Materials(CLSM) evaluated in this study reduces unit weight by mixing foam in the traditional Controlled Low-Strength Material and has lightweight and flowability to be available for backfill materials in construction. Flow test, unconfined compressive strength test, and foamed-slurry unit weight test were performed in this study and the applicability of lightweight foamed CLSM for construction materials was evaluated. The results indicate that the mixture ratio(PA:FA) ranging from 70:30 to 50:50, cement of 7%, foam of 2~3%, and water content of 26.5~29.5% were required to satisfy the following standards such as flow value(i.e., 20cm), unconfined compressive strength(i.e., 0.8~1.2MPa), and foamed-slurry unit weight(i.e., $12{\sim}15kN/m^3$).