Characterization of Bottom Ashesfrom Incineration of Different Compositionsof Municipal Solid Wastes: Implicationsfor its Valorization as a Cementitious Material

Currently, in Chlef (Algeria), Municipal solid wastes (MSWs) are treated by landfill.This work proposes the incineration of MSWs, with the bottom ash (BA) generated being used in cement manufacturing.This treatment is a promising way to achieve a circular economy and reduce the environmental impact of MSWs in Chlef and Algeria.This research focused on two major goals.First, it studied the influence of the raw composition of MSWs incinerated on the characteristics of BAs generated.Second, it investigated the recycling of BAs as supplementary cementitious material (SCM).To achieve the above objectives, one tonne of MSWs and 500 kg of organic MSWs generated in the City of Chlef (Algeria) were incinerated in a rotary kiln, and a part of the ordinary Portland cement (OPC) was replaced by 0 wt%, 5 wt%, 10 wt%, and 20 wt% of the two types of the generated BAs.The results show that the oxides and heavy metal contents were not similar in both BAs.The incorporation of both BAs into cement results in an increase in water demand for normal consistency.The results indicate that the soundness values of all the cement pastes are less than 10 mm.From the results, it is important to mention that there was a delay in the initial setting time for cement prepared with BA from the incineration of one tonne of MSW.Both BAs adversely affected strength at a replacement level of 20 wt%.However, the results also show that both BAs are beneficial when used as SCMs at replacement levels of 5 wt% and 10 wt%, as the physical and mechanical properties of the blended types of cement remain comparable to those of OPC.