The role of graphite, graphene nanoplatelets, and MXene in improving the physical properties and workability of bitumen

This study explores the enhancement of thermal and rheological properties of 60/70 grade bitumen by the incorporation of nano-additives, including graphite, graphene nanoplatelets (GNP), and MXene. This research presents the first performance evaluation of MXene as a nano-additive in bitumen, comparing its effects directly with those of other common additives, GNP and graphite, under identical conditions. Bitumen was modified to assess the impact of these nano-additives on properties such as softening point, penetration, flash point, dynamic shear, and viscosity. Using high-shear mixing and curing methods, modified bitumen samples were prepared and tested following ASTM standards to analyze their workability and performance at elevated temperatures. Key findings show that MXene significantly enhances the softening point (a 1.51 °C increase) and dynamic shear modulus, offering superior high-temperature stability compared to GNP and graphite. Additionally, GNP-modified bitumen exhibited the most substantial reduction in weight loss during aging tests (74% decrease), suggesting improved oxidative stability. Optimal performance across parameters was observed at 1–2% concentrations of nano-additives, with higher dosages resulting in agglomeration and reduced effectiveness. These findings highlight MXene’s potential as an innovative additive for improving bitumen’s durability, with a 59.2% enhancement in rutting resistance at 1–2% concentration, and recommend field trials to validate long-term performance in practical applications. Field validation studies are recommended to assess long-term durability under traffic loading.

Graphical abstract