Lightweight concrete must contain lightweight aggregates that are more susceptible to segregation than traditional concrete. Concrete has increasingly used lightweight fillers but research on segregation analysis is relatively scarce. To systematically investigate the segregation of hollow glass microspheres (HGMs), lightweight cementitious composites (LWCC) with a water-to-cement (w/c) ratio of 0.25–0.5 were investigated. The 3D structure of HGMs in the LWCC was observed with micro-computed tomography (μ-CT), and a rapid CT projection analysis was proposed to evaluate the segregation. The results showed that a slight segregation tendency of HGMs was observed from 0.45, while severe floating segregation occurred at 0.5 of w/c. The flowability of the LWCC increased with the increase of the w/c ratio, but it could not anticipate the segregation behavior. Meanwhile, 2D CT projection image could quickly evaluate the segregation phenomenon so it was proposed that it can be utilized for evaluating potential segregation of cement-based materials.

中文翻译：

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轻质水泥基复合材料中空心玻璃微珠偏析行为的层析分析

轻质混凝土必须含有比传统混凝土更容易离析的轻质骨料。混凝土越来越多地使用轻质填料，但离析分析的研究相对较少。为了系统地研究空心玻璃微球 (HGM) 的偏析，对水灰比 (w/c) 为 0.25-0.5 的轻质水泥基复合材料 (LWCC) 进行了研究。使用微型计算机断层扫描 (μ-CT) 观察 LWCC 中 HGM 的 3D 结构，并提出快速 CT 投影分析来评估分离情况。结果表明，从 0.45 开始，HGM 出现了轻微的偏析趋势，而在 0.5 w/c 时，出现了严重的漂浮偏析。 LWCC 的流动性随着水灰比的增加而增加，但不能预测偏析行为。同时，二维CT投影图像可以快速评估离析现象，因此提出可用于评估水泥基材料的潜在离析。