基于CT断层扫描图像的混凝土粗集料三维虚拟筛分

3-dimensional virtual sieve analysis of coarse aggregate of concrete based on CT scan image

分析了基于数字图像进行混凝土级配分析的主流方法的局限性,并说明了采用工业CT技术手段的独特优势。按照沥青混合料粗集料分级粒径范围制作了5个试件,利用工业CT扫描获取粗集料体积参数。对3类集料体积数字计算方法的准确性进行了比较。通过球面调和变换表征粗颗粒的三维表面轮廓,并在此基础上获取L、W维度位置,并截取出通过筛孔控制平面。经过一系列数字图像处理手段,最终判定集料所能通过的方孔筛的筛孔大小。验证结果表明,基于CT断层扫描图片可以较准确地实现混凝土粗集料的三维虚拟筛分。

The limitations of the mainstream method for the sieve analysis based on the digital image processing were analyzed and the advantages of industrial X-ray CT technique were pointed out. 5 specimens were produced according to the coarse aggregate size range of asphalt mixture. The volumetric parameters of the coarse aggregate were obtained by industrial CT scanning. The accuracies of the 3 methods for calculating the volumetric parameters were compared. The 3- dimensional surface contours were characterized by the spherical harmonic transformation, thus the L, W dimension positions were got, and the control planes passing the sieve were intercepted. The size of the square sieve that the aggregate particle can pass was determined by a series of digital image processing techniques. The validation results show that by means of the new method based on CT scan images the 3-dimensional virtual sieve analysis of the coarse aggregate could be realized more accurately.