Study on the influence of coarse aggregate blends of different sizes and proportions on the homogeneity of asphalt mixtures

Homogeneity has a significant impact on the service life of asphalt pavement. Inhomogeneous asphalt mixture can lead to early damage of asphalt pavement, such as water damage, looseness and fatigue cracking. Therefore, this paper aims to study the influence of the proportions of different size coarse aggregates and particle sizes on the homogeneity of asphalt mixtures. First, the homogeneity index was proposed based on the distribution of aggregates and the coefficient of variation (CV) of particle number. Second, the proportions of twosize and three-size aggregate blends were designed according to the law that the mass fraction of the minimum size aggregate in aggregate blends increased gradually. Then, aggregate blends with various proportions were generated by the Discrete Element Method (DEM). The homogeneity of these aggregate blends and each size aggregate were quantitatively evaluated by CV value. The results showed that the proportions of different size coarse aggregates as well as coarse aggregate sizes have an important influence on the homogeneity of asphalt mixtures.