沥青混合料细观空隙特征对断裂行为的影响

Effect of Asphalt Mixture Microscopic Void Characteristics on Fracture Behavior

空隙作为沥青混合料的天然缺陷,其特征对断裂行为有重大影响。通过小梁弯曲试验和扩展有限元方法研究沥青混合料的断裂行为,并基于计算机断层扫描重构模型进行图像处理提取试件空隙信息,分析空隙参数对试件断裂行为的影响。结果表明,沥青混合料的断裂以沥青-集料界面为主。空隙特征对开裂路径影响显著,其中加权纵横比均值较大的空隙更易发生开裂,而两种方式模拟的裂缝路径上空隙面积率没有显著区别。

As a natural defect of asphalt mixtures,the characteristics of air voids(AVs)have a signifi-cant efeet on fracture behavior.The fracture behaviors of asphalt mixture are studied by trabecular bending test and extended finite element method,and image processing is performed by computed tomnography recon-structed model to extract the specimens AVs information,and the efct of AVs parameters on the specimen fracture behaviors are analyzed.The results showed that the asphalt mixture fracture is dominated on the as-phalt-aggregate interface.The AVs characterstics had a significant ffect on the cracking path,and the AVs with a larger average weighted aspect ratio are more prone to cracking,while the void area ratios on the crack paths simulated by the two methods have no significant difference.