Evaluation of rheological and self-healing properties of asphalt containing microcapsules modified with graphene

Abstract

Asphalt aging has been cited as one of the main reasons for reducing pavement service life, which seriously affect the road traffic maintenance and improving operation efficiency. The method of microencapsulated rejuvenator is a long-term and clean method to improve asphalt aging. The purpose of this study is to evaluate the effect of a graphene modified microcapsule on the rheological properties and self-healing ability of asphalt. The micro morphology and thermal stability of microcapsules were observed by SEM and TGA. The laminated structure of graphene on the surface of microcapsules was observed. The initial thermal decomposition temperature of microcapsules with 5 wt% graphene was 256 °C. The dispersion of microcapsules with graphene was investigated, which was presented the state of microcapsules in matrix asphalt and long-term aging asphalt. The complex modulus and rutting parameter was slightly increased by the addition of 1 wt% microcapsules. The average percent recovery (R) was also improved and non-recoverable creep compliance (Jnr) values were decreased, which the change was intensified with the increase of stress. The self-healing capability was enhanced by adding 1 wt% microcapsule addition. The recovery of asphalt modulus at different rest durations was also been studied.