Development and characterization of anti-cracking epoxy asphalt for steel deck pavement

Despite being commonly utilized in long-span steel deck pavement, epoxy asphalt continues to encounter certain obstacles, including excessive strength and insufficient resistance to cracking. This study proposed a novel approach to incorporating epoxy-terminated polyurethane prepolymers (ETPU) as a toughener to prepare an anti-cracking epoxy asphalt binder. The reaction process, viscosity-time behavior, tensile properties, and dynamic mechanical features of the ETPU-modified epoxy asphalt binder were comprehensively evaluated through a series of tests. Additionally, the fundamental pavement performance, fracture resistance, and fatigue resistance of ETPU-modified epoxy asphalt mixtures were thoroughly assessed. The addition of ETPU can significantly enhance the damping properties of epoxy asphalt, while maintaining its strength and construction retention time without any significant compromise. The formation of a chemical bond between epoxy-amine molecules and asphalt molecules significantly enhanced the compatibility between the epoxy resin phase and asphalt, thereby improving its damping properties. Both the fracture resistane and the fatigue resistance of ETPU-modified epoxy asphalt mixtures were found to be superior to that of commonly used epoxy asphalt mixtures in engineering. The modification mechanism was ultimately derived through the integration of infrared spectral analysis, thereby presenting an economically viable and highly efficient toughening pathway for epoxy asphalt. Therefore, this study indicated a wide-ranging potential for application in the realm of steel bridge deck pavement.