Potensi Material Alternatif Pengganti Semen Dan Agregat Untuk Bahan Baku Industri Beton Di Daerah Kabupaten Tanah Laut Kalimantan Selatan

Abstract

Cement, coarse aggregate, fine aggregate, and water are mixtures of concrete in which besides water, the rest of the components are not sustainable. The utilization of waste-material as an alternative additives or replacement of cement and aggregates becomes the research areas to seek solution for more sustainable materials. In Indonesia, the availability of waste materials such as fly ash and dolochar that can be processed as material alternative can be found in the area of Tanah Laut, South Kalimantan, at PLTU Asam Asam. The objective of this study is to explore the potential of fly ash and dolochar in replacing coarse aggregates. The methodology for the first phase of this study is started by surveying and laboratory testing including aggregate testing, cement testing, and chemical composition using X-ray Fluorescence (XRF). The results of this study show that fly ash from PLTU Asam Asam can be used as material alternative to replace cement since it contains pozzolanic and cementitious properties. Chemical composition of fly ash has passed the requirement such as the percentage of (Al2O3 + SiO2 + Fe2O3) is between 79,26%-91,54% that is higher than 70%, the percentage of SO3 is between 0,46%-0,62% and lower than 4%, and the percentage of MgO is between 2,08%-5,18% that is lower than the requirement of 6%. As for dolochar, it can replace fine aggregate when the size smaller than 5 mm at SSD (Saturated Surface Dry) condition is used. Meanwhile, dolochar with a size larger than 5 mm can be used as material alternative to replace coarse aggregate. The research concludes that fly ash and dolochar has potentials to be used as material alternative in the concrete industry, to support a more sustainable construction material.