It is found that the resin corrosion resistance ability of different systems is different, and in road engineering epoxy resin as a crosslinking curing resin has good corrosion resistance and excellent mechanical properties [10,11]. Epoxy resin is often used as a modifier in asphalt concrete. Epoxy bitumen (EA), one of the most typical thermosetting polymer modified bitumens, is mainly composed of matrix bitumen, epoxy resin (ER), a curing agent, and other additives. As a bridge deck pavement material, it has the advantages of high strength, good fatigue resistance, and excellent high temperature and water stability, as well as corrosion resistance. Thermosetting three-dimensional network polymers are formed by the reaction of ER with bitumen and the curing agent in epoxy bitumen [12,13]. The presence of a curing network provides the EA with good adhesion, thermal stability, and anti-aging properties [14,15,16]. It can resist, to a large extent, the problem of road corrosion caused by fuel leakage during vehicle driving. However, due to its insufficient toughness at low temperatures, the poor compatibility between ER and asphalt, and its high price, it is not widely used on asphalt pavements [17,18]. The SBS modified asphalt mixture has a good low-temperature crack resistance, and the incorporation of SBS can improve the low-temperature fracture toughness of EA [19,20]. In addition, the preparation of modified epoxy bitumen by SBS can enhance the compatibility of ER with matrix bitumen and the flexibility of cross-linked epoxy resin networks. Xu et al. investigated the mechanism of the SBS capacitance for ER through microscopic experiments, including fluorescence microscopy, microcomputed tomography, and gel chromatography . It must be considered that ER is often used in bridge deck pavement projects and the cost of using a large amount is high . The current paper combines low-content ER and SBS to compose the matrix asphalt. We then explore the optimal formula and dosage combination of ER and SBS modifiers through indoor tests and evaluate the performance and oil corrosion resistance of ER/SBS composite modified asphalt. This work provides theoretical support for low-content EA applications in asphalt pavement susceptible to fuel corrosion.
Laboratory testing of the ER/SBS composite modified asphalt penetration, ductility, softening point, and cloth viscosity were combined with regression analysis (SPSS, version 26.0, IBM, Chicago, IL, USA) to determine the regression equation of each index. Furthermore, based on the specification requirements of SBS modified asphalt as the index limit, the nonlinear equation system was derived using MATLAB (version 2021, MathWorks, Natick, MA, USA), and the optimal compound content of the ER and SBS modifier was analyzed according to the solution set. The three index tests and cloth viscosity tests of ER/SBS modified bitumen with the optimal compound content were performed and the simulation results were compared.
The results reveal that the appropriate amount of ER incorporation will not have a significant impact on the low-temperature fission and creep resistance and toughness of the modified asphalt and can meet the road requirements under low temperature conditions. An excessive ER incorporation may strongly affect the interaction between asphalt molecules, which greatly reduces the toughness, low-temperature crack resistance, and the stress relaxation ability of the modified asphalt. Combined with the DSR and BBR test data, when the ER content is 2.3%, the composite modified asphalt can also induce excellent high-temperature rheological properties, meeting the basic low-temperature rheological properties. 2b1af7f3a8