Effects of Epoxy Resin System and Ingredient Content on the Properties of Asphalt and Its Mixtures

To clarify the effect of an epoxy resin (EP) system and ingredient content on the properties of epoxy asphalt (EA) and its mixtures (EAM), which is instructive for the selection of epoxy products and the promotion of its multiscenario application, two commercial EP systems (KD-BEP and KD-HDP, with mass ratios of 56∶44 and 61∶39 between the resin and the curing agent, respectively), were used to prepare EAs with different EP contents (10, 20, 30, 40, and 50 wt%), designated as EPBA and EPHA, respectively. Subsequently, their tensile and rheological properties were compared and evaluated using tensile, dynamic shear rheology, and bending beam rheology (BBR) tests. The pavement performance of different EAMs (EPBAM and EPHAM) was also assessed in a series of laboratory tests. The results demonstrated that 30 wt% EP content was inadequate to form a cross-linking network structure, and EPBA and EPHA exhibited brittle fracture characteristics in the tensile test at −10°C. EPHA possessed better mechanical strength and high-temperature deformation resistance, while EPBA had a significant advantage in low-temperature toughness. The mixture performance test results revealed that the mixture with EP content higher than 20 wt% presented satisfactory comprehensive performance. With the rise of EP content, the elastic component in the asphalt system increased and gradually formed a cross-linking structure, which improved the high-temperature stability, low-temperature cracking resistance, and moisture resistance. Meanwhile, EPBAM had superior low-temperature crack resistance and inferior high-temperature stability compared with EPHAM. Notably, the BBR test appeared unsuitable for analyzing the low-temperature toughness of EA materials, and it is necessary to explore a novel evaluation index.