Self-healing bitumen by microcapsules containing rejuvenator

Abstract

Preservation and renovation bitumen of pavement is a big problem for the whole world. Traditionally, application rejuvenators is the only one method that can restore the original properties of the pavements. However, some puzzles still restrict its successful usage. Microencapsulation is a promising method to apply rejuvenator in bitumen. These microcapsules can break and leak the oily-liquid rejuvenator into microcracks and self-healing the aged bitumen. The aim of this work was to synthesize and characterize the physicochemical properties of novel microcapsules containing rejuvenator by in-situ polymerization of methanol-melamine-formaldehyde (MMF) prepolymer. A two-step coacervation (TSC) was successfully applied to enhance the thermal stability and compactability of shells with the help of styrene maleic anhydride (SMA) as surfactant. Thermal stability, mechanical stability and interface stability of microcapsules in bitumen were investigated. The results showed that these microcapsules containing rejuvenator survived in melting bitumen and in a violent repeated temperature changes. Mechanical properties indicated that the bitumen had the self-healing ability with the released rejuvenator from microcapsules. Microcapsules containing rejuvenator will be a promising product to realize the smart pavements.