MSWI bottom ash as binder replacement in wood cement composites

Nowadays, the incineration of municipal solid waste (MSW) is widely applied, as it reduces the waste 90% by volume and 80% by mass. The main by-product coming from the MSW incineration is bottom ash (BA). Despite numerous studies concerning the uses of this by-product in the construction field, BA is not widely applied because of two main concerns: (1) the disadvantageous morphology of the particle, leading to a high porosity and water absorption and (2) the presence of harmful contaminants, leaching out from the by-product. Because of its porous structure, BA can be suitable as binder replacement for improving insulation properties of wood composites, usually requiring low flexural strength. Therefore, this study will evaluate the influence of a porous binder containing BA and cement on wood wool cement boards (WWCB). The BA and cement are chemically and physically characterized. Thereafter, cement pastes with different replacement levels of BA (0–50%) are produced to measure mechanical and thermal properties. The same mixes are then used to make WWCB. While the thermal conductivity remains unchanged, the mechanical properties benefit from the use of BA up to 30% wt. due to the reduced macro porosity of the final composite.