Solidifikasi/Stabilisasi Fly Ash yang Terkontaminasi Fenol sebagai Bahan Subtitusi dan Pengisi pada Pembuatan Beton

Abstract

The purpose of this study is to investigate the potential use of coal-fired fly ash as a substitute component and filler in the production of concrete. Analysis of fly ash reveals that it contains heavy metals and has an oxide concentration that is identical to that of portland cement. Fly ash waste from PT. SOCI MAS, Portland cement type I, sand, gravel, and water were the materials employed in this study. When using fly ash as a substitute material, percentages of 0%, 5%, 10%, 20%, and 30% of the weight of cement used are used, and when using fly ash as a filler material, percentages of 0%, 20%, 40%, 60%, and 65% are added. Maximum load, compressive strength, and water absorption tests were performed on concrete to evaluate the quality of the final product. Phenol release tests and TCLP tests were performed to assess the quantity of metal concentration released during solidification/stabilization. The best results were obtained using fly ash as a filler material at 65% filler, which produced a maximum load of 825 kN and a compressive strength of 39.494 MPa that is suitable for prestressed concrete. The best results were obtained using fly ash as a substitute material at 10% substitution, which produced a maximum load of 680 kN and a compressive strength of 32,840 MPa. Additionally, the resulting water absorption diminishes the more fly ash is added as a substitute or filler material. The results of the analysis of phenol and TCLP showed that the concentrations of metals and phenols obtained were far below the quality standards, so it can be concluded that fly ash can be used as a mixture in the manufacture of concrete that meets the standards and is free from excessive levels of Cu, Zn, and Ba metals so that it is safe for the environment.