Rejuvenation of Bituminous Binders through Non-Petroleum Based Products: A Rheological Characterization

The reuse and valorization of materials derived from deconstructed pavements (Reclaimed Asphalt Pavement, RAP), represent a key strategy to enhance the sustainability of the road sector. However, the aging of the bituminous binder contained in RAP compromises its rheological properties, making the use of rejuvenating agents essential. This research, developed within the framework of the PRIN SMASHit project, aimed to evaluate the effectiveness of three non-petroleum based agents: two intended for application in bituminous mixtures (RA and RB) and a sunflower oil traditionally employed for food purposes (RC), tested for the restoration of the viscoelastic properties of aged binders. The experimental program involved the preparation of bitumen–rejuvenator blends at dosages of 4% and 6% by weight, subjected to standardized aging through the Rolling Thin Film Oven Test (RTFOT) and the Pressure Aging Vessel (PAV). Rheological characterization was performed using a Dynamic Shear Rheometer (DSR) in frequency sweep mode and complemented with dynamic viscosity measurements with a coaxial cylinder viscometer, in order to describe the viscoelastic behavior and workability of the modified binders. The results confirmed the ability of non-petroleum based agents to influence the properties of aged binders. Overall, the study highlights their potential as a sustainable alternative to petroleum-derived products and provides a basis for further research and practical applications in the field of road pavements.