沥青混合料的抗弯拉性能影响沥青路面的服役质量和寿命，其内部受力决定了抗弯拉性能的优劣。为探究沥青混合料的内部受力特征，采用离散元方法对3点弯曲受力模式下沥青混合料各组分力链进行量化评价。首先，基于图像识别构建了粗集料模板库，实现沥青混合料试件高效离散元3维建模，并提出了3点弯曲仿真方式；然后，可视化表征沥青混合料内部力链分布，提取了各组分力链数据，从组成、强度和角度方面分析了力链特征。结果表明：在3点弯曲受力模式下，沥青混合料的内部力链场表现为拉压分区，粗集料嵌挤仅在受压区生效；SMA13沥青混合料的70.8%内部接触力由沥青砂浆提供，而AC13沥青混合料提供的则为83.2%，粗集料在弯拉受力状态下作用较小，沥青砂浆起主要抵抗外载作用；力链比重随强度的增大而减小，砂浆内部与砂浆-粗集料界面位置的强力链比重基本一致，而粗集料之间受力不均匀，砂浆使沥青混合料内部均匀受力效果明显；粗集料-砂浆界面水平方向的力链强度略高于竖直方向，粗集料力链强度随角度变化的波动起伏大。沥青砂浆在沥青混合料弯拉受力时承担主要荷载，可为沥青混合料的结构设计和性能评价提供参考。

The bending and tensile properties of asphalt mixture affect the service quality and life of asphalt pavement, and its internal stress determines the bending and tensile performance. In order to investigate the internal stress characteristics of asphalt mixtures, this paper adopted the discrete element method to quantitatively evaluate the force chains of each component in asphalt mixtures under the three-point bending mode. Firstly, it constructed a template library of coarse aggregates based on image recognition and realized efficient three-dimensional modeling of asphalt mixture specimen and proposed a three-point bending simulation method. Then the internal force chain distribution of asphalt mixture was visually represented, and data of force chains of each component were extracted. The force chain characteristics were analyzed from the three aspects of composition, strength, and angle. The results show that under the three-point bending mode, the internal force chain field of asphalt mixture exhibits tension and compression zones, and the extrusion of aggregates only takes effect in the compressed zone. 70.8% of the internal contact force of SMA 13 asphalt mixture is provided by the asphalt mortar, and that of AC13 asphalt mixture is 83.2%, indicating that coarse aggregates have little effect under bending and tensile stress and asphalt mortar plays a major role in resisting external loads. The proportion of force chains decrease as the strength increased, and the proportion of strong force chains in the interior of the mortar and the mortar-aggregate interface position is basically the same. The stress between coarse aggregates is uneven, and the mortar plays a significant role in ensuring uniform stress within the asphalt mixture. The strength of horizontal force chains at the aggregate-mortar interface is slightly higher than that in the vertical direction, and the strength of aggregate force chains fluctuates greatly with the change of angle. Asphalt mortar bears the main load during bending and tensile force of asphalt mixture and the research findings can serve as a reference for the structural design and performance evaluation of asphalt mixtures.