Abstract
A comparative study was conducted to determine the effects of graphene and carbon nanotubes on the thermo-mechanical properties of asphalt binder using molecular simulations and experiments. Micro-morphology of graphene and carbon nanotubes was measured by scanning electron microscopy. Thermal stability and glass transition temperature were investigated by differential scanning calorimeter. Simulation results indicated that the Tg had slightly changed for graphene-modified asphalt (GMA) and carbon nanotubes-modified asphalt (CNsMA) and that the thermal expansion coefficients and thermal conductivity increased along with the adding amount of graphene or carbon nanotubes. The Tg calculated by density–temperature method was closer than the experimental Tg and the Tg decreased in the order of CNsMA, GMA and asphalt. Young’s modulus of asphalt, GMA and CNsMA were 9.2658, 25.7563 and 17.8249 GPa at 298 K, respectively, which indicated that thermo-mechanical properties of asphalt showed considerable improvements after the addition of graphene or carbon nanotubes, and carbon nanotubes-modified asphalt and GMA were promising candidates for the future modified asphalt.
Acknowledgements
The authors would like to thank Master Wei Ding studied in Shanghai Institute of Ceramics, Chinese Academy of Sciences for the help of scanning electron microscope tests and providing the preparation methods of graphene and carbon nanotubes.