Study on the Properties of Graphene Oxide–Wood Tar-Based Composite Rejuvenated Asphalt

This study aims at counteracting the problem of rejuvenated asphalt with poor performance and weak secondary anti-aging ability by improving the existing biomass rejuvenator. In this study, a carbon nanomaterial, graphene oxide (GO) with excellent anti-aging performance, was introduced to the wood tar-based rejuvenator (WR) to prepare a composite rejuvenator. Based on laboratory tests, the effects of the GO–wood tar-based composite rejuvenator (GWCR) on the performance of aged asphalt and on the secondary aging performance were investigated, and its rejuvenation mechanism was analyzed. The results indicate that the GWCR can increase the penetration, ductility, and creep rate (m) of aged asphalt while decreasing its softening point, rutting factor (G*/sinδ), and stiffness modulus (S). This indicates that the high-temperature resistance to the permanent deformation ability of aged asphalt degrades, while the low-temperature performance improves, and all values are slightly greater than those of the 70# original base asphalt. After PAV aging, the S value of the GO–wood tar-based composite rejuvenated asphalt (GWCRA) increased by 83.71%, while the m value decreased by 49.45%. The secondary aging resistance of the GWCRA is better than that of 70# original base asphalt, RA-75 rejuvenated asphalt, and wood tar-based rejuvenated asphalt. When adding the GWCR into aged asphalt, the content of saturates and aromatics in the asphalt increases by 1.08% and 11.1%, respectively. In contrast, the content of asphaltenes and resins decreases by 6.288% and 5.9%, respectively. As a result, the colloidal structure of the aged asphalt transfers from a gel to a sol–gel state. The surface roughness of the GWCRA increases by the synergistic effect of GO and wood tar, making its adhesion better than that of the 70# original base asphalt. Adding GO can improve the performance of wood tar rejuvenated asphalt (WRA) with high-temperature deformation resistance and resistance to secondary aging, and effectively make up for the defects in the performance of WRA rejuvenated asphalt, so as to extend the service life of asphalt pavements, thus increasing the value of wood tar engineering applications, which is of great practical significance.