Effects of asphalt mixture structure types on force chains characteristics based on computational granular mechanics
Guoqiang Liu, Dongdong Han, Yongli Zhao, Jiupeng Zhang
Abstract
Force chains are deemed as paths to transfer external loading in asphalt mixtures, and its properties difference can reflect the skeleton performances. In this study, the discrete element method (DEM) models of asphalt mixtures were established. Force chains characteristics of dense-suspended and dense-skeleton types asphalt mixtures were compared. Results indicate that force chains number of dense-suspended type asphalt mixtures is much more than that of dense-skeleton type asphalt mixtures. The force chains length shows exponential distribution for all asphalt mixtures. Fine aggregates are involved in transferring external loading, not just the role of filling. Compared with dense-skeleton types asphalt mixtures, dense-suspended type asphalt mixtures have more proportion of short length force chains. Although there are a large number of force chains in dense-suspended type asphalt mixtures, most of them have lower strength, especially for short length force chains. Comparing with the force chains of dense-suspended type asphalt mixtures, the force chains not only have longer length, but also higher strength for dense-skeleton type asphalt mixtures. The external loading is mainly transferred along the vertical direction, and a little loading tends to expand horizontally. The asphalt mixture skeleton structure has a smaller anisotropy degree that is beneficial to transfer external loading.