中文摘要：

为更好地了解沥青混凝土材料疲劳破坏裂缝的特征与发展规律,有针对性地进行抗疲劳功能型沥青混合料的设计,基于数字图像处理技术,对120余根不同类型沥青混合料疲劳试验小梁试件的疲劳裂缝扩展路径、裂缝长度分布与分形特征进行了定性、定量分析。结果表明：除环氧沥青混凝土裂缝扩展路径接近直线外,普通沥青混合料疲劳裂缝扩展路径一般为曲线,基本沿矿料之间的界面扩展,断面凹凸不平;增强沥青砂浆与集料的黏结性,可有效提高沥青混合料的整体抗拉强度;沥青混合料疲劳试件侧表面贯穿裂缝长度频数分布可用Gauss（正态）分布进行描述,黏结裂缝长度占裂缝总长的60%～70%,远远超过砂浆裂缝;沥青混合料疲劳裂缝具有良好的分形特性,分形维数在1.0～1.5之间。

英文摘要：

To better understand the characteristics and development regularity of asphalt concrete materials fatigue damage crack, targeted for anti-fatigue function asphalt mixture design, a qualitative and quantitative analysis of the fatigue crack growth path, crack length distribution and fractal characteristics are carried out for more than 120 pieces of different types of asphalt mixture fatigue test specimen. The results indicate that apart from epoxy asphalt concrete crack growth path is closer to a straight line, fatigue crack growth path of common asphalt mixtures is generally curved, and along the interface between the aggregates, commonly the extension section is uneven. Enhancing the adhesive properties between asphalt mortar and aggregates can effectively improve the overall tensile strength of the asphalt mixture. The length frequency distribution of asphalt mixture specimen side surface fatigue cracks can be described by the Gauss （Normal） distribution, the length of bond cracks are 60% ～70% of total cracks length, far more than the matrix cracks. Moreover, the fatigue cracks of asphalt mixture have a good fractal characteristics, and fractal dimension is between 1.0～1.5.