Performance Evaluation of Self Healing Asphalt Concrete using Recycled Rejuvenating Agent

Abstract

Asphalt is the most preferred binding material for roadway construction due to the advantages of cost efficiency, noise reduction, and comfortable driving experience. Meanwhile, several factors including UV radiation, oxidation, temperature, moisture, and traffic loads damage asphalt and becomes brittle. Deterioration begins at the micro-level and gradually transforms into macro- cracks that eventually lead to pavement failure. Researchers have proven that asphalt has intrinsic self-healing ability, but it is limited. Thus, damages accumulate beyond asphalt natural healing capacity. This research uses the in-situ crack healing method of encapsulated rejuvenator technology to improve the limited self-healing ability of roads and enhance its service life so that extrinsically induced self-healing ability of asphalt can help it recover the damage incurred during service life. When a crack is induced in the pavement, capsules rupture and releases a rejuvenator which diffuses into the crack and heals it. Ca-Alginate capsules with rejuvenator were prepared. The surface texture and morphology of capsules was assessed using optical microscopy. The thermogravimetric analysis was done to analyze the thermal stability of capsules in asphalt mixture. A moisture susceptibility test was conducted to investigate the water sensitivity of capsules in the asphalt mix. It was found that capsules will improve the moisture susceptibility of rejuvenator encapsulated asphalt mixture. To illustrate the benefits of encapsulated rejuvenator on the pavement service life, the self-healing behavior of capsule-induced asphalt was investigated using the semi-circular bending test and three-point bending beam test. Results of these tests were used to explain the relationship between healing time, temperature, and healing level. Overall, Ca- Alginate containing recycled rejuvenator was found to be suitable for healing for asphalt mix with increased healing temperature and healing time better for healing index.