基于Matlab的沥青混合料内部空隙率测定与分析

为了研究沥青混合料CT图像空隙率大小及其分布特征,基于Matlab图像处理软件对各层位扫描CT图像进行图像增强、图像锐化处理。采用二维最大熵阈值分割法对沥青混合料不同层位的CT图像进行二值化,利用Canny算子模板进行边缘检测,检测出图像边缘内部空隙点数与试件CT图像总点数做熵运算,计算空隙占整个试件的百分率。同时,对试件空隙率检测计算结果差异的显著性进行数理统计检验。结果表明:空隙率随层位呈两头大中间小的分布趋势,验证了沥青混合料内部微观结构的非均匀性;CT图像计算的空隙率均值可以作为试件的空隙率值,同时试验数据结果与图像处理结果具有一致性,表明图像处理具有一定的准确性和可信度。

Measurement and Analysis of Inner Air Voids of Asphalt Mixture Based on Matlab

In order to quantify air voids of asphalt mixture and its distribution characteristics in CT images,the CT images of different layers were strengthened and sharpened based on Matlab image processing software.By using 2D maximum entropy threshold segmentation method,the CT images of different layers of asphalt mixture were processed into binary images.Then,the Canny operator model was used to detect air void numbers and calculate the entropy value of the CT image.The air voids in the whole asphalt mixture specimen was also calculated.The significance of the calculation result difference of air voids of the specimen was statistically tested.The result shows that(1) the air voids at the two ends is bigger than that at the middle of layers,which confirmed that the micro structure of asphalt mixture specimen is not uniform;(2) the calculation result of the air voids of the CT images can be used as the real air voids value of the specimen,and the test data is consistent with the image processing result and it is proved that the image processing is accurate and reliable.