基于数字图像技术的混凝土粗集料空间分布特征

Spatial distribution of coarse aggregate in concrete based on digital image processing technology

为研究混凝土内部粗集料的空间分布特征,通过对混凝土随机截面图像进行亮度转换、分水岭分割和形态学运算等数字图像处理,建立了精确的混凝土试件二维数字模型;采用主轴倾向和级配两项空间分布指标分析了粗集料的空间分布特征。研究结果表明:经过合适的数字图像处理,能够得到混凝土内部粗集料完整的边界图像,对混凝土内部的细观结构进行了较好的表征;混凝土粗集料主轴倾角在水平截面上近似呈现均匀分布的状态,与理想状态下的主轴倾角累积频率曲线的平均误差为14.8%;数字图像处理粗集料级配曲线经过修正后与实际的设计级配有很好的相关性,平均误差为5.78%。

To investigate the spatial distribution of internal coarse aggregate in concrete, the ran- dom horizontal cross-section of the concrete specimen was processed by the digital image technol- ogy on its brightness transform, watershed segmentation and morphological operations. Then the precise 2-D concrete digital model was made based the processed image. The spatial distribution of coarse aggregate was analyzed by using two spatial distribution indexes, namely, shief axis slope and grade curve. The result shows that complete borderless images of concrete coarse ag- gregates can be obtained after the proper digital image processing, and the internal microstructure of concrete was characterized by these images. The chief axis slope of coarse aggregate nearly had the uniform distribution, with the average deviation of 14.8% from aggregated frequency curve in ideal state. The corrected digital image processing grading curve accords well with the design grading curve, with an average deviation of 5.78%. 1 tab, 14 figs, 17 refs.