Gradation and Performance Research of Cold Recycled Mixture

Cold in-place recycling was adopted for a project in China due to the availability of reclaimed asphalt pavement (RAP). Based on the Foshan loop project in Guangdong, the gradation design of cold recycled mixtures (CRM) was optimized by the Bailey Method. Emulsified asphalt and cement were used as additives. Then, the screenings of aggregates in RAP and RAP were analyzed and compared. Additionally, new aggregates and cement were added to dispose the framework structure of the cold recycled mixture, and modified Marshall Tests conducted to determine the optimum amount of emulsified asphalt and water, by which cold recycled mixture was formed and performance experiments of asphalt mixture carried out. Eventually, the results show that the gradation design of cold recycled mixture needs to be adjusted by the screening of aggregates in RAP. Also, cold recycled mixture is suitable for highway sub-grade and pavements of low-grade roads.