Effective Load Transfer Capacity Analysis for Asphalt Mixture Skeleton Based on Main Force Chain Characteristics and Discrete Element Method

To clarify the effective load transfer capacity of asphalt mixture skeletons, granular material mechanics and the discrete-element method (DEM) were introduced to analyze the morphological characteristics of skeleton main force chains (MFCs). Results indicate that the greater number of MFCs is not relevant to higher effective transfer load capacity for the skeleton. An increase in the relative ratio of the III type of force chain in MFC is not conducive to transferring external loading effectively. The MFC number gradually decreases with an increase in nominal maximum aggregate size (NMAS), and the proportion of MFC increases for dense-graded asphalt concrete (AC). For stone matrix asphalt (SMA), the increase of NMAS will reduce the quasilinearity of MFC and be conducive to forming longer MFC, especially for the I type of force chain. An increase of content with aggregate size less than 2.36 mm can improve the number ratio of the III type of force chain. Therefore, an increase in the passing rate of 2.36 mm (P2.36) is not conducive to transferring external loading for AC.