Multi-aging Impact on Rheological and Chemical Properties of Recycled Binder Blends with Asphalt Recycling Agents

Asphalt recycling is becoming a regular activity in road construction, benefiting the economy, the environment, and circularity while preparing for a world less dependent on fossil resources. Therefore, asphalt recycling agents (ARAs) have been identified as important components for producing asphalt mixtures with high reclaimed asphalt (RA) content. As there are many ARAs on the market, as well as many other alternative products, it is essential to ensure that their long-term performance, compatibility, and recyclability are not compromised. In this chapter, two ARAs, one tailored asphalt additive and one waste cooking oil, were used. Blends with 50% of virgin and rejuvenated RA binder were subjected to different aging levels: short (rolling thin-film oven test), long [20 h in pressure aging vessel (PAV)], and prolonged (60 h in PAV) and compared to a reference blend without additive. Rheological and chemical properties were then evaluated after each level, addressing their aging behavior. Fourier Transformed Infra-Red spectroscopy was used to explore the chemical characteristics of binders. More specifically, the ketone peaks (between 1800 and 1650 cm−1) were investigated. Rheological properties were assessed by determining crossover temperature at 1.59 Hz, crossover shear modulus, Glover–Rowe parameter, equi-modulus temperature, and phase angle. The rheological and chemical properties of binder blends containing ARAs were found to be comparable, with no negative effects after long-term aging. However, these properties were still not quite as near to those of virgin binder.