Abstract

Extrinsic self-healing of bituminous materials using encapsulated rejuvenators is a hot topic within road materials. Based on a circular economy vision for more sustainable and resilient asphalt pavements, this study explores for the first time the use of pyrolytic oil from waste tyres as a promising encapsulated rejuvenator to promote the extrinsic self-healing in bituminous materials. Pyrolytic oil-in-water emulsions, and capsules and their components were produced and characterised through gas chromatography-mass spectrometry (GC/MS) and SARA fractions analysis, fluorescence microscopy methods, creaming index, thermogravimetric analysis (TGA-DGT), optical and scanning electron microscopy (SEM), encapsulation efficiency and mechanical properties. Main results showed that the pyrolytic oil capsules presented an adequate morphology for the self-healing asphalt, with a good thermal stability, physical-chemical and mechanical properties. Overall, it was also proven that the pyrolytic oil is a rejuvenator that can diffuse in the aged bitumen reducing its viscosity to promote the self-healing of the microcracks.