Investigation on Indirect Tensile Test of Asphalt Mixture Based on the Discrete Element Method

Abstract The indirect tensile test is commonly used to evaluate crack and fatigue resistance of asphalt mixtures. However, laboratory tests are time-consuming and laborious in general. Numerical simulation provides a technical way for studying the mechanical behavior of asphalt mixtures. In this research, a laboratory test and discrete element method were used to explore the effects of temperature, air void content, loading rate, and the homogeneity of a mixture on the splitting strength of asphalt mixtures. For asphalt mixtures, a three-dimensional random modeling method and two-dimensional modeling method based on X-ray computed tomography and digital image processing were developed. Also, a homogeneity evaluation index based on ring segmentation was proposed. The results show that an increase in loading rate and decrease in temperature resulted in a significant increase in splitting strength. With an increase in voids, the splitting strength of an asphalt mixture decreased. The Pearson correlation coefficient indicates that there seems to be no clear connection between splitting strength and homogeneity, but there is a significant correlation between the homogeneity and differences in the splitting strength.