Rheological properties and aging resistance of asphalt modified with Camellia oleifera fruit shells

Abstract

The increasing traffic demand and sustainability concerns associated with polymer-modified asphalt present new challenges for road engineering. This study explores the use of discarded Camellia oleifera fruit shells (CFS) as a biomass modifier to produce asphalt with varying CFS contents. The rheological and aging properties of the modified asphalt were evaluated using Dynamic Shear Rheometer (DSR), Bending Beam Rheometer (BBR), and Fourier Transform Infrared Spectroscopy (FTIR). The results show that CFS significantly enhances high-temperature rutting resistance by increasing the complex modulus and deformation stability. A moderate CFS content improves low-temperature ductility and crack resistance, while aging resistance is also notably enhanced. Mechanistic analysis suggests that these improvements are due to the modulus-enhancing effect of lignin, the lubricating properties of polyphenols, and their combined antioxidant effects. The optimal CFS dosage is approximately 12 % by weight. Overall, this study demonstrates that incorporating CFS not only improves asphalt performance but also provides a sustainable approach for biomass waste valorization and the development of environmentally friendly road materials.