Abstract: In order to evaluate the fracture performance of asphalt, the geometric model of asphalt fracture performance was established according to the relevant knowledge of elastic mechanics theory, which was decomposed into the superposition of two new configurations. The theoretical relationship of asphalt critical cracking state was derived by using the complex function method, and the theoretical model of asphalt fracture performance with central penetrating crack and without macroscopic crack was obtained by modifying it. SK-70# base asphalt was taken as raw material, and uniaxial tensile test, bending creep test, surface energy test and fracture performance test were carried out respectively. The model parameters were quantified, and the test data were fitted. According to the fitting results, the correlation between asphalt surface energy and fracture performance was discussed to verify the rationality of the model. The research results show that the theoretical model of asphalt fracture performance is reasonable and reliable, which can be modified by introducing plate width coefficient. For asphalt with central penetrating crack, the surface energy can qualitatively characterize the fracture performance, and the larger the surface energy is, the better the fracture performance is. For asphalt without macroscopic crack, the stiffness modulus and surface energy jointly determine its fracture performance.

Key words: highway engineering, base asphalt, fracture performance, surface energy, theoretical model, experimental verification

摘要： 为了评价沥青的断裂性能，根据弹性力学理论的相关知识建立沥青断裂性能的几何模型，将其分解为两个新构型的叠加，运用复变函数解法推导出沥青临界开裂状态的理论关系式，对其进行修正，得到含有中心穿透裂纹和不含宏观裂纹的沥青断裂性能的理论模型。以SK-70# 基质沥青为原材料，分别进行单向拉伸试验、弯曲蠕变试验、表面能测试和断裂性能试验，量化模型参数，将试验数据进行拟合，根据拟合结果讨论沥青表面能与断裂性能的相关性，验证模型的合理性。研究结果表明：推导出的沥青断裂性能理论模型合理可靠，可引入板宽系数对模型进行修正；对于带中心穿透裂纹的沥青，其表面能可定性表征断裂性能，且表面能越大，断裂性能越好；对于无宏观裂纹的沥青，劲度模量和表面能共同决定其断裂性能。

关键词: 道路工程, 基质沥青, 断裂性能, 表面能, 理论模型, 试验验证