Valorizing waste materials as biomass fillers in the production of asphalt mixtures

Purpose The purpose of this study is to valorize waste materials (sawdust and corn cob ashes) as potentially replaced biomass fillers for conventional mineral filler (pulverized quarry dust [PQD]) in asphalt mixture production. Design/methodology/approach Sawdust and corn cob were valorized at 650°C for 2 h, resulting in sawdust ash (SDA) and corn cob ash (CCA). These were then used as PQD replacements at 0–100 Wt. % for asphalt mixture production. The effects of SDA and CCA as biomass fillers were investigated on the mechanical and durability properties of asphalt mixtures. In addition, the asphalt mixture samples were characterized for microstructures and elemental compositions using Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray spectroscopy. Findings The asphalt mixtures showed promising results, suggesting potential benefits for the industry. The bulk specific gravity and percentage of air voids decreased with increasing SDA-CCA content, indicating a potential for improved stability and resistance against rutting, cracking and moisture. The optimum performance was achieved at 50 Wt. % of SDA and CCA replacement levels, with stability and resistance against rutting, wet cracking, dry cracking and moisture significantly higher than the control mixture. FESEM revealed the effects of SDA and CCA, filling the voids and enhancing the asphalt binder-filler adhesion, further supporting the potential benefits of this research. Originality/value This novel research establishes the prospects of replacing SDA and CCA with PQD to produce asphalt mixtures. Besides, the binary blend of SDA and CCA as biomass fillers in place of conventional mineral filler (PQD) for asphalt mixture production is original. Valorizing SDA and CCA as PQD replacements for asphalt mixture production is feasible, promoting waste management, a cleaner environment, sustainability and pavement construction.