A review on Graphene/GNPs/GO modified asphalt

Two-dimensional (2D) materials such as graphene, graphite nanosheets (GNPs), and graphene oxide (GO) are frequently used in the areas of biology, electronics, environment, etc. In recent years, increasing attention has been paid to the application of these materials in pavement engineering. This paper summarizes the progress and challenges of using graphene-like materials in asphalt binder and asphalt mixture. The major conclusions are as follows: 1) The graphene-like materials can improve the high temperature performance, moisture stability, aging resistance, and skid resistance of asphalt binder, but the effect on low temperature performance depends on the dispersion of graphene-like materials in asphalt binder; 2) The effect of graphene-like materials on the surface texture of aggregate in asphalt mixture needed to be further verified; 3) The three methods for the preparation of modified asphalt were summarized: the direct addition method (DAM), the indirect addition method (IAM), and the auxiliary addition method (AAM). Among them IAM and AAM can reduce the usage of graphene-like materials and improve their dispersion in asphalt binder; 4) Only physical reactions exist in the system of graphene modified asphalt (GMA) and graphite nanosheets modified asphalt (GNMA). In the system of graphene oxide modified asphalt (GOMA), the existence of chemical reaction needs to be further verified; 5) The modification mechanism was explained by both the substitution effect hypothesis (SEH) and the intercalation structure hypothesis (ISH).