Recycling of Cement-Based and Biomass Ashes Waste Powders as Alternative Fillers for Hot Mix Asphalts: A Preliminary Laboratory Evaluation

The construction sector has a prominent role in raw materials consumption and environmental depletion due to waste and emissions connected to the production of construction materials and construction/demolition operations. Thus, research is pushing to develop sustainable construction materials, mainly recycling waste and by-products. Following this trend, the present study explores the possible use of two different blends of cement-based waste powder and biomass ashes as filler for the production of asphalt concretes. The materials have been tested following the EN 13043 standard requirements for fillers for bituminous mixtures. Still, the basic performances of hot mix asphalts produced with the recycled materials have been evaluated on a laboratory scale. The physical, chemical, and mechanical characterization of the waste fillers and the bituminous mixtures showed advantages and downsides in the use of the recycled powders for hot mix asphalt production. Despite final performances in line with traditional hot mix asphalt, the chemical composition of the proposed fillers has a negative influence mainly on the water susceptibility of the mixture. However, the findings of the study open new perspectives on future possible applications of the recycled fillers in the road pavements sector.