Comparing the Physical Properties of Coal Bottom Ash (CBA) Waste and Natural Aggregate

Coal bottom ash (CBA) is a co-combustion product material, which may cause hazards to human health and the environment. Rapid growth in technology causes the increase of CBA waste and this situation led to a waste disposal crisis. Reuse waste material as an alternative material instead of natural materials can led to sustainable and environmentally friendly construction. The main objective of this study is to determine the physical properties of CBA and its suitability to be used as replacement material in civil construction. The physical properties test conducted in this research were aggregate impact value test, aggregate crushed value test, flakiness and elongation test. The results show that the ability of CBA to resist sudden shock and repeated load was lesser than natural aggregate (NA). The differences of aggregate impact value (AIV) and aggregate crushing value (ACV), between NA and CBA were 50.4% and 48.9%, respectively. In addition, CBA has higher amount of flaky and elongated particles compared to NA. The flakiness index value for NA and CBA were 7.12% and 26.10%, respectively while the difference value of elongation index between NA and CBA was 37%. However, even though the properties of CBA were not as good as NA, the results for ACV and the flakiness index of CBA meet the minimum requirement of Jabatan Kerja Raya (JKR) Standard Specification which indicates that CBA has potential to be used in civil construction.