Particle Parameters of Asphalt Pavement Milling Recycling Material

Based on laboratory data and literature data, this paper has carried out a study on the particle parameters of asphalt pavement milling recycled materials. From the two indicators of the characteristic particle size and uniformity of the aggregate, the difference between the particle characteristics of the new aggregate and the recycled material, the changes in the composition of the macroscopic particles after the recycled material are extracted in advance and the attenuation law of the asphalt mixture gradation during the service time of the road surface was studied in this paper. The results show that based on the RRS equation, the particle distribution simulation of aggregates, RAP materials and mixtures can be simulated, and two characterization parameters of characteristic particle size and uniformity coefficient can be obtained. Under the condition of the same particle size range, the characteristic particle size of RAP material is smaller than that of the new aggregate, the uniformity improved, and the particle size distribution range becomes narrow. There is a good mathematical relationship between the characteristic particle size and uniformity coefficient of the RAP material after extraction. The characteristic particle size of the RAP material after extraction reduces, while the uniformity coefficient gets further reduced. With the extension of the age, the characteristic particle size and uniformity coefficient of the mixture have shown a significant linear attenuation. In order to ensure the quality stability of recycled mixtures, the classification and management of RAP materials should be strengthened in the actual recycling design and application process.