Design Optimization and Rheological Property of Recyclable Epoxy Asphalt

Epoxy asphalt serves as a vital material in infrastructure construction; however, its inefficient regeneration process hampers broader adoption. To overcome this challenge, the concept of recyclable epoxy asphalt, harnessing the reversibility of dynamic covalent bonds, has been introduced. In prior research, we successfully developed and validated recyclable epoxy asphalt incorporating Diels–Alder reaction bonds. This study focuses on enhancing performance through design optimization and rheological property assessment of recyclable epoxy asphalt. By employing response surface methodology, 13 distinct compositions varying two parameters and evaluating three mechanical properties were devised to determine the optimal material formulation for recyclable epoxy asphalt. Subsequently, the recyclable epoxy asphalt underwent controlled aging and regeneration processes. Finally, the study evaluated the chemical composition and rheological properties of recyclable epoxy asphalt before and after regeneration. The optimization procedure identified the ideal composition of recyclable epoxy asphalt as 54% asphalt, 15% epoxy monomer, and 31% curing agent. The durability of the Diels–Alder reaction bonds’ reversibility under prolonged use is pivotal to the regeneration process. Rheological analysis suggests that moderate use enhances the performance of recyclable epoxy asphalt, with partial recovery achievable through the regeneration process. The preparation-aging-regeneration cycle underscores the practicality of recyclable epoxy asphalt, offering substantial environmental benefits and promising future applications.