Characterization of carbon nano-fiber modified hot mix asphalt mixtures

Multifunctional nanomaterials hold the potential to cost-effectively enhance the efficiency and long-term performance of transportation materials. This study focuses on the mechanistic characteristics of electrically conductive carbon nano-fiber (CNF) modified hot mix asphalt (HMA) mixtures. HMA mixtures were modified with varying percentages of CNF. The viscoelastic, strength, permanent deformation and fatigue characteristics of the neat and modified mixtures were evaluated under indirect tension mode. In order to understand the micromechanical behavior of CNF in HMA mixtures, the microstructure and morphology of fracture surfaces of HMA samples were studied using Scanning Electron Microscopy (SEM). It was found that the addition of CNF improves the performance of HMA mixtures in a unique way. This paper presents the understanding of CNF behavior and its impact on the overall mechanical characteristics and laboratory performance of HMA mixtures.

► Mechanistic characteristics of Carbon Nano-fiber (CNF) modified hot mix asphalt mixtures (HMA) are presented.
► Fatigue life and resistance to permanent deformation substantially improved due to CNF modification.
► No significant difference found between ITS and toughness properties of CNF modified and processed mixtures.
► CNF modified HMA mixture exhibited higher stiffness and dynamic modulus as compared to the processed mixtures.