Investigation of sisal fiber incorporation on engineering properties and sustainability of lightweight aggregates produced from municipal solid waste incinerated bottom ash

Abstract

The large-scale disposal of bottom ash resulting from municipal solid waste incineration poses a significant challenge in terms of effective management. While Lightweight aggregates made of municipal solid waste incinerated bottom ash, referred to as MSWI BA, show promise, their practical application is hindered by low structural strength and the presence of certain contaminants. To address this, a novel and green solution is proposed in this study, which involves utilizing sisal fibers (SF) to enhance the solidification of the synthesized aggregates. In this study, the synthesized lightweight aggregates (SLWAs) consisting of cement, different replacement levels of ground MSWI BA (60%, 70%, and 80%), and/or the cut SF were manufactured by a disc pelletizer. The influence of incorporating SF on the SLWAs was investigated across various aspects, encompassing the physical characteristics, strength performance, microscopic properties, and sustainability. The results showed that when SF was incorporated, the production efficiency of coarse SLWAs was considerably improved, especially up to a 66.5% increase with under the 70% replacement level of MSWI BA. Moreover, the surface roughness and strength were improved due to the SF addition. In the system of the CEM-MSWI BA matrix, the fiber incorporation not only accelerates the cement hydration reaction but also fills the pore generated from the swelling of metallic aluminum in MSWI BA, achieving the strength enhancement of SLWAs. More importantly, some contaminant ions including chloride, chromium, and copper from MSWI BA, could be effectively absorbed and solidified by the SF. Furthermore, the utilization of SF in SLWAs brings about great sustainability concerning greenhouse gas emissions and production costs. Consequently, incorporating SF proves to be an effective and green solution, thus promoting the practical implementation of the SLWAs.