低温开裂是薄层沥青混凝土常见的病害，为了揭示薄层沥青混合料的低温开裂行为，开展结合裂纹观测和数字图像处理的半圆弯曲试验以及基于细观结构黏聚区模型的有限元数值模拟研究，通过模拟得到的加载力-位移曲线验证了模型的适用性，进一步分析试件内部的应力变化。结果表明：采用数字图像处理技术可很好地显式沥青混合料的低温开裂行为；细观结构有限元模拟适用于分析沥青混合料的开裂行为；跨中截面最大拉应力和中性轴位置与材料的断裂属性有很好的相关性。

low-temperature fracture is the normal distress of the thin-layer overlay asphalt mixture. To reveal the low-temperature cracking behavior, semicircular bending tests combined with crack observation, digital image correlation and a finite element numerical simulation based on the meso-structure cohesive zone model were carried out. The applicability of the model was verified by the load-displacement curve and crack paths. The results show that the low-temperature cracking behavior of asphalt mixture can be well demonstrated by digital image processing. The simulation of asphalt mixture meso-structure is suitable for analyzing the cracking behavior. Furthermore, the maximum tensile stress and neutral axis positions on the mid-span section are correlated with the properties of the materials.