Investigating the advanced thermomechanical properties of coiled carbon nanotube modified asphalt

Coiled carbon nanotube (CCNT) as a novel nanomaterial has the potential to enhance the thermomechanical properties of asphalt. In this study, three typical coiled carbon nanotubes are constructed to modify asphalt, and the thermomechanical properties of asphalt nanocomposites are investigated through molecular dynamics simulations. The results show that the structural deformations of CCNTs occur in the front loops during the pullout process and the initial shapes of CCNTs can be restored after the complete pullout. The anchoring effect is found to improve the shear resistance owing to the rotational structures of CCNTs. The asphalt molecules can attach to the rotational surfaces of CCNTs through the π-π stacking interactions during the pullout process, and saturate molecules can flexibly move into the space between different loops of the deformed CCNTs. CCNT3 nanocomposite has the highest shear capacity at all temperature ranges, and CCNT2 nanocomposite is more temperature susceptible than other nanocomposites. The existence of CCNTs can greatly restrict the mobility of asphalt molecules, and the effect of CCNTs on the deformation resistance at high temperature ranges is more effective than that of the low temperature ranges. The molecular interactions and reinforcing mechanisms between various CCNTs and asphalt components can be elucidated, promoting CCNTs as a new form of asphalt reinforcement and enhancing the long-term durability of asphalt pavement. © 2024 Elsevier Ltd