基于XCT扫描图像的混凝土粗骨料二维细观形态

混凝土中粗骨料的微细观形态特征对混凝土宏观力学性能具有重要影响.基于边长为20 mm的混凝土立方体试件的XCT(X-ray computed tomography)扫描图像,通过构建的规则程度指标、凹凸程度指标对骨料二维形态特征进行了研究.结果表明:可选择长宽比、椭圆相似度、棱角度三个参数来有效表征粗骨料二维形态特征;通过对大量骨料二维投影进行形态指标统计分析,发现长宽比、椭圆相似度、棱角度的数值分别主要集中在区间(1,3)、(0.8,1)、(1,1.1)内,且三者之间满足二次多项式分布.研究结果可为混凝土粗骨料三维形态表征研究提供基础参考.

Two-dimentional Mesoscale Morphology Research of Coarse Aggregates in Concrete Based on XCT Scanning Images

The mesoscale morphology characteristics of coarse aggregates in concrete have an important influence on its macroscopic mechanical properties. Based on the XCT (X-ray Computed Tomography) scanning images of a concrete cube specimen with a side length of 20 mm, the two-dimensional mesoscale morphology characteristics of the aggregates were studied through two aspects: the regularity and convexity. The results show that the aspect ratio, the ellipse similarity, and the angularity can be selected to effectively characterize the two-dimensional morphological characteristics of the coarse aggregates; according to the statistical analysis of morphological indicators of a large number of aggregates, it is found that the aspect ratio, the ellipse similarity, and the angularity are mainly located in the areas of (1,3), (0.8,1) and (1,1.1) respectively, and they are in the relationship of quadratic polynomial distribution. The research results can provide a fundamental reference for the research on the three-dimensional morphology characterization of coarse aggregates in concrete.