Performance evaluation and modification mechanism analysis of asphalt binders modified by graphene oxide

This work presents a laboratory study conducted to evaluate the potential impacts of different graphene oxide (GO) dosages on properties of non-modified binder and SBS modified binder. The effects of GO on viscosity, rheological properties, creep and recovery behavior, cracking resistance, and thermal properties of unaged/RTFO aged binders were characterized respectively. It was demonstrated that the addition of trace amounts of GO (no more than 0.2 wt%) enhanced the paving temperature (120-135 °C) viscosity, high-temperature elasticity and rutting resistance of non-modified/SBS modified binders. The performance improvements were attributed to an increase in the crosslinking degree of the binders induced by the GO. The amount of GO needed to improve the high-temperature performance of the non-modified binder is smaller than that needed for the SBS modified binder. The modification mechanism of GO to non-modified binder includes both chemical reactions and physical blending, whereas it only entails physical blending in the case of SBS modified binder.