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为了揭示粉煤灰和磨细矿渣对混凝土微观结构初始缺陷的影响规律,采用高分辨率X-射线微焦点CT(X-ray Micro-CT)图像对具有不同胶凝材料的4个系列高性能混凝土进行了研究.混凝土微观结构和缺陷过滤之后的高分辨率三维图像均由Micro-CT配套的图像软件进行了重建.基于二维和三维图像分析得到了混凝土内部缺陷的尺寸分布和体积分数,并与常温饱水法的试验结果进行了对比.研究结果显示:矿物掺和料作为胶凝材料加入混凝土之后,由于其颗粒填充效应和火山灰效应,显著改变了硬化混凝土的微观结构特征以及初始缺陷的尺寸和空间分布特征;在水胶比和集料尺寸分布保持不变的条件下,矿物掺和料的掺入与否,是引起高性能混凝土展示出不同力学特性的主要原因.
In order to reveal the influence of fly ash and ground slag on the initial defects of concrete microstructure, high resolution X-ray micro-CT (X-ray micro-CT) Concrete were studied.The high-resolution three-dimensional images of concrete microstructure and defect filtration were reconstructed by Micro-CT imaging software.The size distribution and volume fraction of internal defects of concrete were obtained based on two-dimensional and three-dimensional image analysis, The results show that the addition of mineral admixture as a cementitious material significantly changes the microstructure and initial defects of the hardened concrete due to its particle filling effect and pozzolanic effect The size and spatial distribution of mineral admixtures are the main reasons that cause high performance concrete to exhibit different mechanical properties under the condition of constant water-cement ratio and aggregate size distribution.