Viability Study on Fly Ash and Bottom Ash from Combustion Waste

Abstract

The substitution or addition of new supplementary cementitious materials (SCM) in the production of variety of construction materials has gained much interest. One of the examples of SCM is incineration ash which consist of fly ash (FA) and bottom ash (BA) which are the residues from the ignition of biomass and can brings applicable ecological advantages. However, the properties of this new materials need to be investigated to ensure its full potential can be developed. Therefore, this study is initiated to identify the characteristics of incineration ash from local source in Malaysia. To identify the elemental components of ashes, most widely method was adopted which is using X-Ray Fluorescence (XRF). The quantity of unburned carbon in fly ash is measured by loss on ignition, which has a major influence on the product’s characteristics. In addition, specific gravity and density were also determined and comparison has been made with cement. In this study it was found out that XRF results shows that both FA and BA consist of the same mineral composition with OPC majorly in silica, aluminium, calcium, and iron which makes is suitable to be used in the concrete. For LOI, the value for BA is much higher compared with FA due to the amount of unburnt carbon in its original compositions and the incomplete burning due to insufficient contact time in the furnace. Based on the result obtained for LOI, the average LOI value for FA and BA is 17.33 % and 44.67 %, respectively. As expected, for the specific gravity and density, FA having the lowest specific gravity and density. The density obtained for FA is 755 kg/m3 and for BA is 593 kg/m3. Overall, the use of incineration ash can be fully investigated by exploring other parameter that influence the performance of construction materials.