Study the epoxy resin content on the performance of hot-mix epoxy asphalt binder and mixture used in steel deck pavement

Hot-mix epoxy asphalt (HEA), a polymer material for steel bridge deck pavements, has garnered attention due to its superior performance. The optimal content of different hot-mix epoxy resins varies due to their distinct compositions. This study investigated the viscosity-temperature characteristics, microscopic topography, mechanical properties, and mixture performances of epoxy asphalt binders and mixtures with varying self-prepared epoxy resin contents. Techniques such as laser scanning confocal microscopy (LSCM), tensile tests, mixture performance tests, viscosity tests, and scanning electron microscope (SEM) tests were employed. Results revealed that HEA with an epoxy resin concentration of at least 40% meets the specifications (JTG/T 3364-02-2019). Increasing the epoxy resin content enhances viscosity, tensile strength, Marshal stability, dynamic stability, and flexural tensile strains but reduces elongation at break. LSCM and SEM images showed that during curing, spherical epoxy particles agglomerate to form a three-dimensional cross-linking network structure and thermosetting cured epoxy asphalt when the epoxy resin content is at least 40%.