Application of bottom ash as cement replacement in wood wool composite boards

Nowadays, the incineration of municipal solid waste (MSW) is widely applied, as it reduces the waste of 90 % by volume and 70 % 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 these 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. However, the presence of a porous structure can be used as an advantage, during the production of thermal and acoustical insulating composite materials, as the binder matrix has a relevant role in the insulating properties of blended cements. This study will evaluate the influence of a porous binder in wood wool composite boards (WWCB), mainly applied as insulation material and ceiling tiles. After the washing treatment, chemical and physical characterization of the bottom ash fines and binder will be performed. Thereafter, the determination of mechanical and thermal properties on the paste at different replacement level (0-50%) will be conducted. The same replacement levels are then tested in combination with wood wool as far as thermal conductivity and mechanical strength is concerned. While the mechanical properties have a benefit by the replacement of by-products, the thermal conductivity results steady, due to the overall limited porosity of the final composite in presence of BA.