Design and performance study of waterborne epoxy cold recycling asphalt mixtures

The green and low-carbon concept has significantly influenced various industries, including asphalt pavement construction. Cold recycling technology offers notable advantages in reducing carbon emissions during pavement construction. However, traditional cold recycling methods often fail to utilise aged asphalt. They rely heavily on emulsion or foamed asphalt binders, which contradicts the low-carbon principle. Additionally, performance limitations of existing binders prevent these technologies from adequately addressing the deficiencies of RAP. This study introduces a novel approach to cold-recycled asphalt mixtures using cost-effective waterborne epoxy resin to mitigate RAP performance deficiencies. Two diffusion components were incorporated to enhance the utilisation of aged asphalt and improve the overall performance of cold-recycled mixtures. A design method for waterborne epoxy cold recycling asphalt mixtures (WECRM) and suitable evaluation methods for road performance were developed. The results demonstrate that WECRM exhibits excellent high-temperature performance. The inclusion of diffusion components significantly improves low-temperature properties and reduces moisture sensitivity. With a modulus ranging from 12,000 to 13,000 MPa, WECRM is ideal for surface layer applications. Furthermore, the analysis highlights its suitability for lower pavement layers to resist rutting, enabling high-value applications of cold recycling technology while maintaining cost efficiency.