Study on Interference Phenomenon of Coarse Aggregate in Dense Graded Asphalt Mixture

Abstract

In order to quantitatively study the interference phenomenon of asphalt mixture coarse aggregate in the compaction process, the digital image technology was used to detect the mixture slice. The interference coefficient of coarse aggregate of asphalt mixture was proposed as the quantitative index of interference phenomenon. The results show that from initial compaction to final compaction, The interference coefficient of 2.36mm $\sim$ 4.75mm and 4.75mm $\sim$ 9.5mm coarse aggregate decreases significantly, and the interference degree of each grade of coarse aggregate increases significantly. The interference degree of coarse aggregate at the bottom of the specimen is greater than that at the top of the specimen, but the difference of interference degree at each vertical position decreases with the progress of compaction. The change of coarse aggregate interference degree is mainly concentrated in the early and middle stages of compaction, and the increase of interference in AC-13C and SMA-13 decreases by 68.8% and 82.2% respectively in the middle and late stage.