Study of coffee husk ash addition for clay soil stabilization

Abstract

Industrial solid wastes have become a difficult problem in some developing countries, especially in Indonesia. The environmentally friendly issue regarding how to decrease industrial wastes by reuse or recycling process has become famous in recent years. Coffee husk ashes in this research were attained from burned waste coffee husk which can be considered as solid waste material from the coffee processing industry. In this study, clay soil obtained from Cot Bagie Village, Blang Bintang, Aceh was mixed with coffee husk ashes. Several soil physical properties test was conducted such as specific gravity, Atterberg limit, and grain size distribution by following ASTM standard. The physical parameter of soil was evaluated with the addition of 3%, 6%, 9%, and 12% coffee husk ashes by soil dry weight. The result shows that the physical properties of soil were improved if compared to untreated soil. A further mechanical laboratory test in soil mechanics was suggested for more advanced analysis of effect in soil-coffee husk ashes mixing.