Developments of nano materials and technologies on asphalt materials – A review.

Due to its nature of large surface area and small size, nano-material shows specific characteristics compared to the common material and exhibits some novel properties and incredible features which make it possible to be applied in the field of asphalt pavement as an additive. This review focuses on introducing the main nano materials and related techniques used for nano-modified asphalts and major performance characteristics at various states. Some conventional test results including viscosity, dynamic modulus, stiffness, rut depth, indirect tensile strength and so on were employed to characterize the rheological and engineering performances of nano-modified asphalts and some innovative technologies such as atomic force microscopy, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were effectively utilized to explore their micro structures and molecular components. It can be found that the addition of nanomaterials could dramatically enhance the properties of an asphalt material such as visco-elasticity, high temperature properties, and the resistances to aging, fatigue and moisture. In addition, nano-particle type, content and production process were mainly studied and other factors such as binder type and particle size also need to be considered to explore the modification mechanism and effect. The properties of both nano-material and original binder played the key roles in determining optimal production process parameters. In addition, the degree of dispersion was governed by some factors such as the mixing temperature, duration and speed. [ABSTRACT FROM AUTHOR]