Mechanical properties of asphalt mixture containing sunflower oil capsules

Embedding encapsulated rejuvenators in asphalt mixture is a sustainable way to extend the lifetime of roads, and minimise the negative environmental impacts of current maintenance processes. The aim of this article is to investigate the use of encapsulated oil for use as rejuvenators in asphalt pavements. With this purpose, capsules of 5 different diameters have been built and their mechanical strength and composition characterised. Then, the capsules have been mixed in asphalt mixture, and their resistance to mixing and compacting has been observed. Finally, the effect of capsules in the indirect tensile strength, modulus, and fatigue life of asphalt mixture test samples has been quantified. It was observed that bigger capsules contained more oil and were less strong than smaller capsules. In addition, most of the capsules resisted the mixing and compaction processes. Asphalt mixture with capsules presented reduced indirect tensile strength and modulus, which happened because the capsules had lower strength than required. Finally, the fatigue life of asphalt mixture was not affected by the capsules.