PEMANFAATAN ABU ECENG GONDOK DI DANAU TONDANO SEBAGAI BAHAN PENGGANTI SEBAGIAN SEMEN PADA CAMPURAN BETON

Abstract

Lake Tondano is the largest lake in North Sulawesi Province, which plays an important role in the social and economic life of the community. However, excessive growth of water hyacinth causes silting and a decline in the quality of the ecosystem. This study was conducted to utilize water hyacinth ash as a partial replacement for cement in concrete mixtures and to analyze its effect on the compressive strength of concrete. The variations in the addition of water hyacinth ash used were 3%, 4.5%, and 6% of the cement volume in the planned concrete quality of K-250. The results of the 28-day compressive strength test showed an increase in the compressive strength value as the percentage of water hyacinth ash increased. Normal concrete without admixture produced an average compressive strength of 26.1 MPa, while the addition of 3%, 4.5%, and 6% resulted in 26.7 MPa, 27.26 MPa, and 27.3 MPa, respectively. The optimum composition was obtained at a mixture of 6% with the highest compressive strength of 27.3 MPa. Thus, water hyacinth ash can be used as an environmentally friendly substitute for cement and supports the sustainable management of Lake Tondano.