UTILIZATION OF ALUMINIUM SLAG AND FLY ASH AS CEMENT SUBSTITUTE IN NORMAL CONCRETE MIXTURES

Abstract

The progress in infrastructure development in Indonesia has a significant impact on various sectors. Cement is the primary material for concrete in infrastructure. Aluminum slag and fly ash waste have the potential to replace cement. This study aims to examine the possibility of utilizing aluminum slag as a substitute for cement in normal concrete. Meanwhile, fly ash is widely used commercially as a supplementary cement replacement material. This research is quantitative with an experimental approach on normal concrete with a quality of K-300. In this experiment, the variations of aluminum slag tested were 0%, 1.5%, 3%, 4.5%, 6%, and 7.5%, while fly ash was used at a constant rate of 15%. The samples were in the form of cubes measuring 15 x 15 x 15 cm and were tested at the ages of 7, 14, 21, and 28 days. The results showed that the optimal aluminum slag content was 1.5%, as higher levels led to the formation of air voids in the concrete, resulting in a decrease in volume weight and compressive strength. Although the use of fly ash in normal concrete generally increases compressive strength, the chemical effects of aluminum slag in this study were more dominant in reducing the compressive strength of the concrete compared to the enhancement effects produced by fly ash.