Integrative evaluation of utilization the nanomaterials as a modifier to asphalt mixtures: traditional and Superpave tests

Abstract

Nanomaterials are increasingly used to improve asphalt binder and mixture performance. This research aims to evaluate the performance of asphalt binder and asphalt mixtures modified with Nano-metakaolin (NMK) using both conventional and Superpave testing methods. The experimental program conducted on the asphalt binder included penetration, softening point, flash point, and absolute viscosity tests. In addition, asphalt mixture performance was assessed through Marshall stability, indirect tensile strength, and rutting tests for both unmodified and NMK-modified mixtures. Furthermore, dynamic shear rheometer (DSR) tests, as part of the Superpave system, were conducted to determine the dynamic shear modulus (G*) of both asphalt binder and mixtures. The results indicated that the incorporation of NMK reduced penetration values, increased the softening point, and enhanced viscosity, reflecting improved binder stiffness and temperature susceptibility. Moreover, NMK significantly increased the dynamic shear modulus, indicating better resistance to deformation under loading. At the mixture level, NMK modification improved key mechanical properties, including stiffness, resistance to permanent deformation (rutting), and fracture resistance. A dosage of 7% NMK by weight of asphalt showed notable improvement in mixture strength. However, based on Superpave evaluation, the optimal NMK content ranged between 5 and 7%, providing the best balance in resistance to rutting, fatigue, and cracking. Overall, the findings demonstrate that incorporating NMK into asphalt materials enhances mechanical performance, reduces structural deterioration, and offers potential environmental benefits, making it a promising additive for advanced asphalt pavement applications.