Coal Ash Waste Utilization for Environmentally Friendly Road Pavement Materials

Abstract

Indonesia is boosting electricity supply, where coal fired power plants are most widely used. Burning coal activity will produce Fly Ash Bottom Ash (FABA) that categorized as Hazardous and Toxic Substances. The production of FABA are 6.598.493 tons (2019) and will increase along with the 35, 000MW program. The research purpose is to study the utilization of FABA from PLTU Labuan Angin as road pavement material that not only fulfill required specifications, but has better performance and environmentally safe. The experimental method was chosen by laboratory testing. Criteria for utilization of FABA as road pavement material, must be carried out with the use of material that capable to binding FABA so that it doesn’t disintegrate Test results showed that FA is type F with CaO levels <10% and LoI 4.27%. Characteristics testing also showed results such as specific gravity of FA 2.64 and BA 2.56, absorption 3.24%, sand equivalent 95.35%. Utilization for base layers with a composition of 75% BA, 25% FA, and 9% PCC produce γd 1.71%, Wopt 5.84%, and UCS 33.05kg/cm2. This utilization is the most effective, because it absorbs more volumes, binding cement, and compaction with heavy equipment can also prevent FABA from released so it is environmentally safe.