<scp>Rheological</scp> Properties and Microstructural Characteristics of Different Fractions of Regenerated Asphalt From Co‐Pyrolysis Oil of Sugarcane Bagasse and Waste High‐Density Polyethylene

ABSTRACT This study conducted co‐pyrolysis of sugarcane bagasse and waste high‐density polyethylene under Hydrogen Zeolite Socony Mobil‐5 catalysis. The separated fractions were investigated for their potential as rejuvenators in reclaimed asphalt pavement. Gas chromatography–mass spectrometry, dynamic shear rheometer, bending beam rheometer, Fourier‐transform infrared spectroscopy, gel permeation chromatography, and atomic force microscopy were employed to analyze the molecular composition, rheological properties, and microscopic changes during asphalt aging and rejuvenation. A thorough examination of the test results indicates that the regeneration efficiency is not solely dependent on the average molecular weight of the oil fractions. Instead, the chemical composition of the oil also plays a critical role in this process. Among the three separated pyrolytic fractions, the fraction primarily composed of alkanes does not have the lowest molecular weight. However, it demonstrates superior capability in facilitating the diffusion of macromolecules within the aged asphalt. As a result, this fraction achieves the most optimal regeneration performance. Building upon these findings, molecular dynamics simulations were employed to further elucidate the rejuvenation mechanism by analyzing cohesive energy and mean square displacement.