Waterborne Epoxy Resin–Polyurethane–Emulsified Asphalt: Preparation and Properties

To obtain a waterproof binding material for bridge decks with properties of high bonding strength at high temperatures and high flexibility at low temperatures, a waterborne epoxy resin–polyurethane–emulsified asphalt (WEPEA) was prepared which can be constructed in a cold state and cured rapidly at room temperature. The composition of WEPEA was determined based on the tensile strength and elongation at breaking. The road performance of WEPEA was systematically investigated based on its high-temperature bonding properties, low-temperature flexibility, adhesion, waterproofing performance, and aging resistance. In addition, the performance of WEPEA was compared with that of SBS-modified asphalt and rubber asphalt. The viscosity variation and micromorphology of WEPEA were investigated, and the compatibility and stability of each component were verified. The results show that waterborne polyurethane can effectively improve the flexibility of emulsified asphalt with a high content of waterborne epoxy resin. WEPEA exhibited excellent bonding strength, crack resistance and anti-impact properties, adhesion to aggregates, and water stability. These properties of WEPEA were all superior to those of the SBS-modified asphalt and rubber asphalt.