Abstract X-ray micro-computed tomography (μCT) scanning is a proven technique with applications in geoscience, soil science, and geotechnical engineering. Here we apply the technique to investigate the effects of cation treatments on clayey soil micro-fabric in a frozen state. We imaged six suites of frozen cation-treated soils (montmorillonite, kaolinite, illite, illite-smectite, chlorite, and Copper River heterogeneous soil) at a resolution of 8.17 μm. Although this resolution was insufficient to observe differences in microaggregate formation as a result of cation treatment, we did observe micro-lenticular ice structures in the smectite-bearing soils that were invisible to the unaided eye. Quantitative analysis of the morphometric parameters from the illite-smectite and Copper River sample suites provided results that supported the visual observations, with the Copper River heterogeneous soil being more frost susceptible than illite-smectite, regardless of cation treatment. The μCT results of these small soil cores also indicate that within the Copper River suite, the Ca2+-treated and Na+-treated samples are the most and least frost susceptible, respectively, which is in agreement with previous frost heave testing. Results from this study indicate that μCT morphometric parameters can be used to quantify micro-lenticular ice lens formation in small samples and to serve as a quality control on sample preparation.

中文翻译：

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通过 μCT 扫描可视化阳离子对冻土的处理效果

摘要 X 射线显微计算机断层扫描 (μCT) 扫描是一种经过验证的技术，可应用于地球科学、土壤科学和岩土工程。在这里，我们应用该技术来研究阳离子处理对处于冻结状态的粘质土壤微织物的影响。我们以 8.17 μm 的分辨率对六组冷冻阳离子处理土壤（蒙脱石、高岭石、伊利石、伊利石-蒙脱石、绿泥石和铜河异质土壤）进行了成像。尽管该分辨率不足以观察由于阳离子处理而导致微团聚体形成的差异，但我们确实在含蒙脱石的土壤中观察到了肉眼看不到的微透镜状冰结构。伊利石-蒙脱石和铜河样品组的形态参数的定量分析提供了支持目视观察的结果，无论阳离子处理如何，铜河异质土壤比伊利石-蒙脱石更易受霜冻影响。这些小土芯的 μCT 结果还表明，在 Copper River 套件内，Ca2+ 处理和 Na+ 处理的样品分别是最易受霜冻影响和最不易受霜冻影响的样品，这与之前的冻胀测试一致。这项研究的结果表明，μCT 形态测量参数可用于量化小样品中微透镜状冰晶状体的形成，并作为样品制备的质量控制。不管阳离子处理。这些小土芯的 μCT 结果还表明，在 Copper River 套件内，Ca2+ 处理和 Na+ 处理的样品分别是最易受霜冻影响和最不易受霜冻影响的样品，这与之前的冻胀测试一致。这项研究的结果表明，μCT 形态测量参数可用于量化小样品中微透镜状冰晶状体的形成，并作为样品制备的质量控制。不管阳离子处理。这些小土芯的 μCT 结果还表明，在 Copper River 套件内，Ca2+ 处理和 Na+ 处理的样品分别是最易受霜冻影响和最不易受霜冻影响的样品，这与之前的冻胀测试一致。这项研究的结果表明，μCT 形态测量参数可用于量化小样品中微透镜状冰晶状体的形成，并作为样品制备的质量控制。