# Evaluation of Aging Resistance of Graphene Oxide Modified Asphalt
###### Abstract  
Graphene oxide (GO) has a unique layered structure with excellent gas and liquid blocking properties. It is widely used in many areas, such as gas sensors, carbon-based electronics, impermeable membranes, and polymeric composite materials. In order to evaluate whether GO (1% and 3% by weight of asphalt) can improve the aging resistance performance of the asphalt, 80/100 penetration grade asphalt (90 A) and styrene-butadiene-styrene modified asphalt (SBS MA) were used to prepare the GO modified asphalt by the melt blending method. The surface morphology of the GO was analyzed by scanning electron microscope (SEM). The UV aging test was conducted to simulate the aging during the service period. After UV aging test, the physical performances of GO-modified asphalts were tested, and the I\({}_{\text{C=O}}\) and I\({}_{\text{S=O}}\) increments were tested by Fourier transform infrared spectroscopy (FTIR) to evaluate the aging resistance performance of the GO modified asphalt. In addition, the rheological properties of GO modified asphalts were studied using a dynamic shear rheometer (DSR). The SEM analysis indicated that the GO exhibits many shared edges, and no agglomeration phenomenon was found. With respect to the physical performance test, the FTIR and the DSR results show that GO can improve the UV aging resistance performance of 90 A and SBS MA. In addition, the analysis indicated that the improvement effect of 3% GO is better than the 1% GO. The testing on the rheological properties of the modified asphalt indicated that the GO can also improve the thermo-oxidative aging resistance performance of asphalt. G 2017 7 702 40.3390/app70/0702 40.  
to generate the free radicals in the initial stage. The excitation sources are the thermal and light excitations [6; 7]. There are many possible ways in preventing the asphalt from being aged or in reducing the rate of asphalt aging. Some of these techniques include the following: (a) by reducing the excitation energy (thermal energy or light energy); (b) by reducing the formation rate or concentration of the initial free radicals; or (c) by preventing contact of oxygen with the asphalt, which can reduce the reactant concentration (O\({}_{2}\)) of the oxidation reaction in the aging process. Inorganic nano-materials, such as layered double hydroxides (LDHs) [8], montmorillonite [9; 10], and carbon black [11; 12], have a layered structure and are excellent barriers for oxygen, which can be used in improving the anti-aging performance of asphalt. However, the compatibility between inorganic materials and organic asphalt is poor, making it difficult for inorganic materials to disperse well in the asphalt; because of the van der Waals forces or the electrostatic forces, they tend to aggregation easily [13]. These drawbacks decrease the barrier performances and reduce the modification effects of the modifiers. Graphene oxide (GO) is a type of layered inorganic nano-material with a molecular structure roughly the same as that of graphene. GO shows excellent performance in gas and liquid blocking, which is similar to that of graphene [14; 15]. The difference of GO compared with graphene is that there are many active oxygen-containing functional groups on the layers and the lamella edges of the GO, which endows GO with good compatibility toward inorganic and organic materials, and makes the graphene oxide-modified material have a low permeability of gas and liquid [16]. In another word, GO not only has the unique layer nanostructures with excellent oxygen barrier performance, but also has good compatibility with the asphalt. Therefore, it is important to conduct more research in this area to determine the effect of GO on the properties of virgin and modified binders. In order to evaluate to effects of GO on the anti-UV aging performance of the asphalt, two types of asphalt and two levels of the GO contents (1% and 3% by weight of the binder) were utilized in preparing the GO-modified asphalt by the melt-blending method.