Rheological analysis of self-healing property of microcapsule-containing asphalt

Novel anionic urethane ionomers were synthesized, encapsulated, and added to asphalt. Accordingly, microcapsule-containing asphalts displayed better rheological properties than the pure one. Shear strength, G* (complex shear modulus) exhibited microcapsule-containing asphalts improved over rest period, it reached 98% of its original strength at 24-h rest time after break as compared to only 74% for pure asphalt. Therefore, microcapsule (core: anionic urethane ionomer)-containing asphalts possess excellent self-healing potential. The anionic urethane solution remained in the core of the microcapsule after break, It represented the core solution and microcapsule itself endured the harsh condition of mixing. In a comparative study, polymer (anionic urethane ionomer)-added asphalt showed better modification effect than microcapsule (core: anionic urethane ionomer)-containing asphalt. However, from the view of self-healing properties, microcapsule-containing asphalt showed better healing effect, which may be attributed to the ionic bonding among anionic urethane ionomers. The polymer solution with high intermolecular force, filled the crack of the asphalt and pulls the opposite ends together; hence, the original properties were restored.