关键词: 道路工程；沥青混合料；细观结构；图像处理；数值模拟

Abstract: Based on digital image processing technology, the meso-structure of asphalt mixtures was studied. Firstly, the research progress of static and dynamic recognition of asphalt mixture meso-structure was reviewed. Then, a flowchart of digital image processing technology was listed and the method of obtaining the internal structure image of asphalt mixture (X-ray CT technology) was introduced in detail. The research progress in describing the internal structure characteristics of mixture through image processing technology, that is, aggregate shape and distribution, contact characteristics and void distribution rule, was discussed. Finally, the three kinds of numerical simulation methods with finite element, discrete element and boundary element and the virtual test on the meso-structure characteristics of asphalt mixture were introduced. The research shows that X-ray CT non-destructive scanning technology can better identify the internal meso-structure characteristics of asphalt mixtures; the numerical simulation combined with finite element, discrete element or boundary element methods can establish an organic relationship between the internal meso-structure and macro performance of asphalt mixture; the application of virtual test can help to understand the macro test results. However, in the study of aggregate shape and distribution, a unified evaluation index has not yet been formed and different researchers use different evaluation indexes. The accuracy and application scope of X-ray CT technology need to be further improved. There is no effective method to distinguish aggregate, asphalt mortar and void. By summarizing the application of digital image processing technology to the meso-structure of asphalt mixture, it is expected to provide reference for the follow-up macro-meso-micro research of asphalt mixture.

Key words: highway engineering; asphalt mixture; mesoscopic structure; image processing; the numerical simulation