Study on the Performance of Epoxy Asphalt with Different Matrix Asphalt Contents

Epoxy asphalt, as a new pavement material, is receiving more and more attention. Exploring the influence of matrix asphalt contents on epoxy asphalt can not only maximize the performance of epoxy asphalt but also provide insight into the intrinsic mechanism of epoxy asphalt. This paper studied the mechanical properties, adhesion properties, atomic force microscopy (AFM), fluorescence microscopy (FM), and infrared spectroscopy quantitative analysis of epoxy asphalt prepared with different matrix asphalt contents. The mechanical properties were tested using direct tensile testing, and the results showed that the modulus of the epoxy asphalt gradually decreased as matrix asphalt contents increased, and the presence of matrix asphalt increased the elongation at break of the epoxy asphalt. The best mechanical properties were achieved when the matrix asphalt content reached 40%. The FM analysis showed that with increasing matrix asphalt contents, the epoxy resin phase in epoxy asphalt changed from the original continuous phase to the dispersed phase, which corresponds to the change of mechanical properties of epoxy asphalt with different asphalt contents. The surface free energy (SFE) of epoxy asphalt and aggregate was measured by the contact angle of different liquids on the sample surface. The adhesion work between different kinds of epoxy asphalt and aggregates can be calculated by bringing the SFE data into the equation. The results showed that the epoxy asphalt with 40% matrix asphalt content has the best adhesion to the aggregate, which was also verified by the roughness results obtained from AFM test. The contents of matrix asphalt in epoxy asphalt was quantified by attenuated total reflection (ATR) infrared spectroscopy, and the relationship equation between different matrix asphalt contents and infrared-specific peak area was established. Thus, the contents of matrix asphalt in epoxy asphalt was determined directly by infrared spectroscopy, which can reduce human errors in the construction process and ensure the quality of epoxy asphalt pavement during construction.