Self-Crosslinking Waterborne Acrylate Modified Emulsified Asphalt via DAAM-ADH: A Dual-Enhanced Solution for Pavement Performance

Emulsified asphalt is widely used for pavement maintenance due to its ease of application. However, its use is limited by poor high-temperature stability and low bonding strength. This study attempted to prepare a self-crosslinking waterborne acrylate (SWA)-type admixture using a diacetone acrylamide (DAAM)-adipic dihydrazide (ADH) crosslinking system and applied it to emulsified asphalt to ultimately obtain self-crosslinking waterborne acrylate-modified emulsified asphalt (AMEA). The research explored the effects of SWA on the fundamental properties, rheological characteristics, microscopic morphology, and bonding performance of AMEA. Results indicated that SWA undergoes self-crosslinking reactions during the demulsification process, forming a continuous and stable network structure that significantly enhances the strength of emulsified asphalt while improving softening point and high-temperature stability. Rheological analysis revealed that within the 10–15 phr dosage range, the influence of frequency on emulsified asphalt was minimized, with notable improvements in high-temperature elastic recovery and deformation resistance. Particularly when the dosage exceeds 10 phr, the material demonstrates adaptability to high-traffic environments. Pull-off tests demonstrated that SWA can increase the interlayer bonding strength of emulsified asphalt by over 50%. However, SWA exhibits some negative impact on the low-temperature ductility of emulsified asphalt, necessitating cautious dosage control during application. This novel self-crosslinking waterborne acrylate-modified emulsified asphalt, with its excellent bonding performance and superior high-temperature stability, emerges as a crucial material choice for pavement preventive maintenance.