Abstract:
This study aims to introduce lignin as a bio-additive to modify the base asphalt and
investigate the high-temperature rheological properties of lignin modified asphalts and
virgin asphalt. In this study, asphalt PG 58-28 was selected as the virgin asphalt, and four
contents, 2%, 4%, 6% and 8%, of the total binder by weight of lignin were incorporated in
the base binder. Rotational viscosity, dynamic shear rheometer, and multiple stress creep
recovery tests were conducted to characterize the rheological performances of different
types of asphalts. The results showed that the incorporation of lignin increased the
viscosity of virgin asphalt at different rotational speeds. The activation energy showed an
increasing trend as the lignin increased compared with the virgin asphalt. Meanwhile, the
lignin incorporated into the asphalt binder increased the elastic components, and improved
the resistance of asphalt binder to the permanent deformation regardless of the lignin
contents. The addition of lignin in the asphalt binder could retard oxidation reactions that
occurred in the asphalt during the rolling thin film oven aging. This study could provide a
prospective foundation for the utilization of lignin extracted from waste biomass as an
exceptional and renewable bio-additive in the field of asphalt pavement engineering
