Effects of Epoxy Resin Content on Properties of Hot Mixing Epoxy Asphalt Binders

Abstract

Hot-mix epoxy asphalt has superior performance as bridge deck pavement material. However, its high cost hinders the application of epoxy asphalt in road pavement. This study investigated the effects of epoxy resin contents on epoxy asphalt performance, aiming to seek out a cost-effective proportion. Specifically, the macromechanical properties, chemical compositions, and microstructure transformation of epoxy asphalt were evaluated by a tensile and viscosity test, Fourier transform infrared spectroscopy (FTIR) test, and fluorescence microscopy test, respectively. Finally, a brief cost analysis was conducted. Results indicate that when the epoxy resin content exceeds or equals 40%, both tensile strength and elongation of epoxy asphalt meet the performance requirements regulated in the specification. In addition, the enhanced epoxy resin content may also boost the viscosity-increasing rate of epoxy asphalt, especially at high temperatures. Furthermore, the areas of 1,085, 1,108, and 1,118 cm−1 wavenumbers of epoxy asphalt infrared spectrum demonstrate good positive correlations with the epoxy resin contents. Besides, according to the fluorescence microscopy test result, after the curing process, the initial spherical epoxy resin particles tend to agglomerate, and a cross-linked spatial structure may form when the epoxy resin content exceeds or equals 40 wt%. Finally, combining the performance and cost analysis, the 40 wt% epoxy resin content can achieve a good balance between the material cost and pavement performance.