INVESTIGATING SELF-HEALING BEHAVIOUR OF MICRO-CAPSULE INDUCED ASPHALT CONCRETE

Abstract

Binders rheological properties are affected due to several factors including UV radiation, oxidation, temperature, moisture damage and traffic loads. This leads to pavements more prone to damage. Encapsulated rejuvenator technique is used to enhance the self-healing ability of asphalt mix. When crack appears, capsules ruptures and releases rejuvenator, which diffuses into crack and heals it. In this research, Ca-Alginate capsules containing waste cooking oil with changing oil/water ratios were prepared. The thermogravimetric analysis was done to analyze thermal stability of capsules in asphalt mix . Moisture susceptibility test was conducted to confirm the water sensitivity of capsules. To illustrate the benefits of encapsulated rejuvenator on the pavement engineering, the self-healing behavior of capsule-induced self-healing asphalt was investigated by Semi Circular Bending Test (SCB) and 3 Point Bending Test. Cracked asphalt mixture recovered 40 % of intial peak load at 25°C versus 14% of asphalt mixture without capsules. 3 Point Bending test was performed at four different temperature. Samples with capsules recovered 53% of initial strength in comparison to 11% of samples without capsules.