Reducing Epoxy Resin Content in a Thermosetting Epoxy Asphalt Mixture: A Feasible Method to Facilitate Application

Abstract

Epoxy asphalt (EA) with an epoxy resin (EP) content of 50 wt% has been widely used in steel bridge decks and airport pavements. However, the high cost of EP and the high EP content in EA limit the application of this material in pavement engineering. Hence, it is meaningful to explore the possibility of reducing the EP content in EA to minimize the construction cost and diversify the application scenarios. In this study, low-content thermosetting epoxy asphalt mixtures (LTEAM) were prepared using binders with EP contents of 32, 34, 36, 38, and 40 wt% to investigate the laboratory performance of LTEAM while evaluating its technical applicability. The basic properties and dynamic characteristics of the LTEAM were analyzed through a series of indoor tests. The dynamic modulus master curve was established, and atomic force microscopy was utilized to explore the improvement mechanism of the moisture damage resistance. Furthermore, the LTEAM with an EP content of 36 wt% (LTEAM36) was preferably selected, and its performance and cost were compared with the epoxy asphalt mixture prepared with a binder of 50 wt% EP content (EAM50). The results demonstrated that the rise in EP content promoted the formation of cross-linked structures and the increase in binder roughness, which positively improved the moisture damage resistance of the LTEAM. The addition of EP improved the elastic properties and modulus of the LTEAM, and its high-temperature rutting resistance enhanced with the increase of EP content, but the low-temperature crack resistance continued to decline. Skid resistance of the LTEAM was not significantly affected by the variation of EP content. Additionally, LTEAM36 had prominent cost and low-temperature performance advantages compared with EAM50. In general, the excellent overall performance and lower cost of the LTEAM36 demonstrate that it is feasible to reduce the EP content in EAM, which can help its promotion and application in pavement engineering.