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.

摘要

力链被认为是沥青混合料中传递外部载荷的路径，其性能差异可以反映骨架性能。在这项研究中，建立了沥青混合料的离散元法（DEM）模型。比较了稠密悬浮型和稠密骨架型沥青混合料的力链特性。结果表明，致密悬浮型沥青混合料的力链数远多于致密骨架型沥青混合料。力链长度显示所有沥青混合物的指数分布。细骨料参与传递外部载荷，而不仅仅是填充的作用。与密骨架型沥青混合料相比，密悬型沥青混合料具有更多的短长度力链比例。密悬型沥青混合料中虽然有大量的力链，但大部分强度较低，尤其是长度较短的力链。与密悬型沥青混合料的力链相比，密质型沥青混合料的力链不仅长度更长，而且强度更高。外部载荷主要沿垂直方向传递，少量载荷趋于水平扩展。沥青混合料骨架结构的各向异性程度较小，有利于外荷载的传递。而且对于致密骨架型沥青混合料也有更高的强度。外部载荷主要沿垂直方向传递，少量载荷趋于水平扩展。沥青混合料骨架结构的各向异性程度较小，有利于外荷载的传递。而且对于致密骨架型沥青混合料也有更高的强度。外部载荷主要沿垂直方向传递，少量载荷趋于水平扩展。沥青混合料骨架结构的各向异性程度较小，有利于外荷载的传递。