Multiscale evaluation of the effects of Organosolv lignin on asphalt materials

Abstract

The increasing demand for road infrastructure, combined with the need to reduce greenhouse gas emissions, has intensified the interest in sustainable alternatives for asphalt use, which currently accounts for approximately 6% of all industrial emissions. Among these alternatives, lignin—a natural biopolymer found in plans and a relevant byproduct of the paper industry—has demonstrated to have antioxidant and UV protection properties, which can extend the service life of asphalt mixtures. This work investigates the influence of Organosolv lignin on asphalt materials at two scales: i) asphalt binder (micro-scale), and ii) asphalt mortars (meso-scale). Linear viscoelastic properties of both materials at different ageing conditions were evaluated using different addition doses of lignin (0, 4, 8 and 12% by weight of the asphalt binder for asphalt modification and 0, 8 and 14% by weight of asphalt binder for mortars) at different ageing conditions, and a chemical characterization was conducted to assess the interactions between the lignin and the asphalt binder. The findings highlight the potential of this type of lignin as an additive for enhancing the response and durability of asphalt materials.