Microstructure in Adhesion Development Process and Strength Formation Mechanism in Early Stage of Cold Recycled Mixture with Emulsified Asphalt

With the large-scale maintenance and renovation of asphalt pavement, a considerable amount of reclaimed asphalt pavement (RAP) will be generated. Stacking these wastes occupies a large amount of land and seriously damages the ecological environment. Hence, efficient regeneration of RAP through recycling technology has gained more and more attention. In this paper, some topics were reviewed to further promote the cold recycling (CR) technology and better follow-up the research progress. First, it discussed the raw materials and the differences and similarities between cement-emulsified asphalt mortar (CEAM) and cold-recycled mixtures with emulsified asphalt (CRME). Second, it reviewed the adhesion development of emulsified asphalt mastic, the application of X-ray technology in microscopic study of CRME and the characteristic of strength development of CRME. The adhesion development of CRME begins with the process of demulsification and hydration caused by the migration and dissipation of water inside the emulsified asphalt mastic. In addition, many factors would influence this process simultaneously. However, the microbehavior mechanism of internal water transport in emulsified asphalt mortar has not yet been thoroughly revealed, and it lacked scientific measurement research on the promoting effect of complex conditions on the development of adhesive properties of mixtures. Therefore, in this paper, they were suggested for future research.