The aggregate distribution in asphalt mixtures was analyzed based on digital image processing. The splitting test model based on two-dimensional cross sections of asphalt mixtures was established by the finite element method. The effect of aggregate distribution on the mechanical properties of asphalt mixtures was numerically analyzed and verified by the laboratory splitting test. Results show that the aggregate distribution in asphalt mixtures can be assessed by the index of aggregate distribution based on digital image processing. The aggregate distribution in asphalt mixtures deteriorates with an increase in the nominal maximum aggregate size. There is an obvious relationship between aggregate distribution and variations in the mechanical properties of the virtual splitting test of asphalt mixtures. The worse the aggregate distribution is, the greater the variation coefficient of the average pressure head reaction forces is．
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