The Properties of Different Healing Agents Considering the Micro-Self-Healing Process of Asphalt with Encapsulations

Improving the self-healing performance of asphalt by employing encapsulation technology is a topic of wide interest. This study investigated the performance of sunflower oil, engine oil, and waste cooking oil based on the microhealing mechanism of asphalt with compartmented polymeric fiber. Capillary flow, contact angle, Brookfield viscosity, bar thin layer chromatography, and fatigue–recovery–fatigue tests were conducted to characterize the capillary flow capacity, wetting ability, viscosity reduction ability, suitability of components, and performance restoration ability of the different kinds of healing agents. The diffusion process of sunflower oil in asphalt was simulated using molecular dynamics. The results showed that sunflower oil exhibited the best capillary flow capacity, viscosity reduction ability, and the fastest wetting rate in asphalt. Engine oil exhibited the largest wetting work and the best recovery performance related to fatigue. The diffusion process of sunflower oil in asphalt could be divided into two stages. Two major factors (aging and higher temperature) increased the diffusion rate of sunflower oil in asphalt. The comprehensive analysis showed that sunflower oil was the most suitable to be encapsulated to improve the self-healing performance of asphalt.