Szeląg Maciej
Faculty of Civil Engineering and Architecture, Lublin University of Technology, 40 Nadbystrzycka Str., 20-618 Lublin, Poland.
Materials (Basel). 2018 Mar 29;11(4):520. doi: 10.3390/ma11040520.
In the paper the cluster cracks of cement paste that has been modified with metakaolinite was analyzed. The samples were loaded with an elevated temperature based on a thermal shock. To describe the crack structure, three stereological parameters were proposed to measure: (i) the cluster average area ( A ¯ ); (ii) the cluster average perimeter ( L ¯ ); and (iii) the crack average width ( I ¯ ). The computer image analysis was implemented in the study, and 4 series of samples were subjected to the examination. In two series, metakaolinite was used as a substitute for 10% of a cement's mass. An assessment of the basic physico-mechanical characteristics of the cement matrix was also carried out. The structure of the cement paste was considered as a highly concentrated dispersion system, in which the interactions between the cement's grains at the initial stage of the structure self-assembly affect the crack characteristics. The study has been supplemented with microstructural investigations using a scanning electron microscope and an X-ray microanalyzer. The conducted research indicated the direction of changes in the geometrical characteristics of thermal cracks if the technological variables of the material are subjected to modification. It was also confirmed that the cluster structures have fractal character and can be analyzed and observed on many levels of a structural heterogeneity.
本文分析了用偏高岭土改性的水泥浆体中的簇状裂缝。基于热冲击对样品进行高温加载。为描述裂缝结构，提出了三个体视学参数来测量：(i) 簇平均面积（(\overline{A})）；(ii) 簇平均周长（(\overline{L})）；以及 (iii) 裂缝平均宽度（(\overline{I})）。本研究采用了计算机图像分析，并对4组样品进行了检测。在两组样品中，偏高岭土用作水泥质量10%的替代物。还对水泥基体的基本物理力学特性进行了评估。水泥浆体的结构被视为一种高度浓缩的分散体系，其中在结构自组装初始阶段水泥颗粒之间的相互作用会影响裂缝特性。该研究还补充了使用扫描电子显微镜和X射线微分析仪进行的微观结构研究。所进行的研究表明了如果材料的工艺变量发生改变，热裂缝几何特征的变化方向。还证实了簇状结构具有分形特征，并且可以在结构非均质性的多个层面上进行分析和观察。
