Characterization of Unaged Asphalt Binder Modified with Carbon Nano Particles

In recent years, nanotechnology has been utilized in many engineering applications. In this technology, nano-sized particles are used in improving the properties of various materials. The construction industry, in general, has not embraced this technology; however, these particles could be used to enhance the physical and chemical properties of the materials such as asphalt binders. The objective of this study was to investigate and evaluate the rheological properties of three asphalt binder sources containing various percentages of carbon nano particles. The experimental design for this study included the utilizations of three binder sources (PG 64-22), one type of nano particle, and four nano dosage percentages (0.2%, 0.5%, 1.0%, and 1.5% by weight of the binder). The following rheological properties were tested and evaluated: viscosity, performance grade, creep and creep recovery, and frequency sweep. The results of the experiments indicated that the addition of nano particles was helpful in increasing the viscosity, failure temperature, complex modulus, and elastic modulus values as well as in improving rutting resistance of the binder. On the other hand, the content analysis of nano particles showed that a relatively low percentage (＜0.2%) of nano particles did not have a significant effect on improving the binder properties while a relative high percentage (＞1.0%) of nano particles is recommended for the modification of an asphalt binder.