中文摘要：

沥青混合料是一种由集料、胶浆和孔隙组成的非均质材料，一般被认为是一种粘弹性材料，其力学行为介于弹性和塑性之间，采用弹塑性断裂力学更适合评价沥青混合料的抗裂性能．J积分理论可以避开分析裂纹尖端附近复杂的应力应变场，物理意义明确，可以有效的评价沥青混合料的抗裂性能，断裂韧度．Jc可以很方便的采用预切缝的半圆弯拉试验直接获得．为了评价材料本身特性对断裂韧度Jc影响，在MTS试验系统上进行了3种级配的沥青混合料的断裂韧度试验．采用基于数字图像处理技术的有限元方法对半圆弯拉试验进行了模拟，并将数值模拟的结果与试验的结果进行了对比分析．结论表明，断裂韧度Jc可以作为一有效的评价沥青混合料抗裂性能的指标．

英文摘要：

Asphalt mixture is one kind of heterogeneous material composed of aggregates, binder and air voids, which was generally considered as one viscoelasticity material with the mechanical behavior between elastic and plastic, and thus, it is more proper to evaluate the asphalt mixture fracture resistance from the Point of elastic-plastic mechanics. The J-integral theory is with very distinct physics meaning so that it can avoid analyzing the complicated stress-strain field at crack-tips, and can effectively evaluate the fracture resistance of the asphalt mixture. In this study, the fracture toughness Jc was conveniently deter- mined from load-deformation data of a simple three-point bending fracture test using notched semi-circular specimens. In order to appraise the material itself characteristic influence on the fracture toughness Jc, the semi-circular bending test were performed with three kinds of mixtures with different gradations in a MTS experiment system. Based on the digital image processing techniques, the Finite Element Model was con- structed to simulate the experiments. The numerical results were compared with the experimental results. Results showed that the fracture toughness Jc could be used as a effective index to evaluate the fracture resistance of the asphalt mixture.