Aging Resistance and Microcharacteristics of Asphalt Modified by Biochar from Spent Coffee Grounds: Fid-Bau Portal

Aging Resistance and Microcharacteristics of Asphalt Modified by Biochar from Spent Coffee Grounds

Chen, Zheng / Yu, Deliang / Feng, Zhengang

Major global consumption of coffee has led to the generation of a substantial amount of spent coffee grounds (SCG), which contribute to environmental burdens. Research on using SCG for asphalt modification is limited. This study aimed to investigate the effectiveness of using biochar from spent coffee grounds (SBC) produced through low-oxygen pyrolysis as a modifier for asphalt, to enhance high-temperature performance and aging resistance. The results demonstrated excellent compatibility between SBC and asphalt binder without causing agglomeration. The introduction of SBC significantly enhanced asphalt’s high-temperature stability and resistance to deformation, while some adverse effects on low-temperature performance were found. The inclusion of SBC improved the anti-aging properties of asphalt, as indicated by various aging performance indices. A decreasing trend was observed for sulfoxide ( $S ═ O$ ) $1,030 {cm}^{- 1}$ . Atomic force microscopy (AFM) images revealed the changes in the size and shape of beelike structures, with smaller bee structures observed in SBC-modified asphalt (SBCMA). Overall, these microscopic structures were consistent with the rheological properties. Due to the improvement of high-temperature stability and anti-aging properties, SBC could prove to be an environmentally friendly and sustainable modifier for asphalt.