This paper reviews the advances in using nano-materials in hot mix asphalt. The clay nano-particles are the primary materials applying in asphalt construction. Adding nano-particles like nanoclay, nanosilica, and nanotubes in asphalts normally increase the viscosity of asphalt binders and improves the rutting and fatigue resistance of asphalt mixtures. Using nanoclay as the second modifier in polymer modified asphalts can improve the storage stability and the aging resistance of polymer modified asphalts. Various Atomic Force Microscopy (AFM) techniques (e.g. tapping mode imaging, force spectroscopy, and nano-indentation) as well as X-ray diffraction (XRD) experiments can be conducted on modified asphalt binders to characterize the micro or nano-scale structures of nano-asphalts. Through the reasonable selection of nano-materials used in asphalt, nano-modified asphalt can offer many benefits in cold regions.
