基于CT扫描与图像处理技术的沥青混合料空隙特征分析

Characterization of Voids in Asphalt Mixtures with Different Grading Methods and Different Grading Types

为了探究沥青混合料空隙特征,以不同级配类型与成型方式的沥青混合料为研究对象,采用CT无损扫描技术获取大量断面图像,应用Matlab软件对断面图像的空隙部分进行识别与分析,得到了空隙在试件内部的分布规律以及空隙分形维数的变化规律。采用压力机模拟沥青混合料马歇尔稳定度的试验过程,并在不同阶段扫描试件,获得其断面图像,确定了试验过程中混合料内部空隙的变化过程。结果表明:马歇尔试件的空隙率与空隙分形维数呈现出外部大、中间小的分布规律,而旋转压实试件的空隙率与分形维数分布较为均匀;在马歇尔稳定度的试验过程中,空隙面积与数量减少,试件先被压密,后随着荷载增大,空隙面积与数量增加,空隙逐渐变宽,直至试件破坏。

To explore the void characteristics of asphalt mixtures,asphalt mixtures with different gradation types and molding methods were used as the research object,CT non-destructive scanning technology was used to obtain a large number of cross-sectional images,and Matlab software was used to identify and analyze the void parts of the cross-sectional images.The distribution law of the voids inside the specimen and the variation of the fractal dimension of the voids was acquired.Press was used to simulate the Marshall stability test process of the asphalt mixture,and the specimens were scanned at different stages to obtain the cross-sectional images to determine the mixture during the test and the changing process of internal voids.The results showed that the porosity and fractal dimension of the Marshall specimens presented a large external and small distribution law in the middle,while the porosity and fractal dimension of the rotating compaction specimens were more evenly distributed.During the Marshall stability test,the area and number of voids were reduced,and the specimen was first compacted,and then as the load increases,the area and number of voids increased,and the gap gradually widened until the specimen was destroyed.