Assessment of Dispersion and Physical Characteristics of Asphalt Binders Enhanced with Graphene

This study investigates the dispersion and physical performance of VG30 asphalt binders modified with reduced graphene oxide (rGO) and graphene nanoplatelets (GNP). These nanoparticles were blended with the asphalt binder in varying proportions (0, 0.5, 1, and 1.5%) using a high-shear mixer. The softening point tests were performed on both unaged and samples aged for two and six hours using the Rolling Thin Film Oven (RTFO). Storage stability was assessed over a 48-h period at 163 °C, and fluorescence microscopy was used to examine the uniformity of the nanomaterials within the raw binder. The test results demonstrated that rGO and GNP significantly influenced the physical characteristics of the neat binder. It was observed that all modified asphalt samples showed increased softening point value with respect to aging. However, the addition of rGO or GNP reduced the SPI, which increased again when the content exceeded 1%. Storage stability tests revealed that incorporating up to 1.5% of rGO and GNP into the base binder-maintained uniformity during high-temperature storage, indicating compatibility between the nanomaterials and the asphalt binders. Fluorescence microscopy revealed that rGO and GNP were uniformly dispersed in the asphalt binder up to a concentration of 1%.