Temperature increases in saturated clay alter the physicochemical clay-water interactions and may lead to the conversion of bound water into free water. These changes significantly influence the physical, chemical, and engineering properties of clays, which are critical for geotechnical and geological engineering and minimizing risks in areas with expansive clay soils. However, quantifying this phenomenon remains challenging in the literature. This study presents a robust experimental approach for quantifying the thermal-induced conversion of bound water in clays, providing valuable insights into the mechanisms governing their thermo-mechanical behavior. A novel experimental method is proposed to quantify the degenerated bound water content in a clay system subjected to temperatures ranging from 20 to 50 °C. The research employs the siphon principle to examine volume changes in a clay system at elevated temperatures, focusing on measuring the conversion of bound water to free water. This method accounts for thermal expansion of both the soil constituents and the confining glass cylinder, as well as potential evaporation losses. To validate the setup's accuracy, a calibration test using standard Ottawa sand with negligible bound water was performed. After measuring system error, the primary outcome was calibrated. Results showed that at 30 °C, 40 °C, and 50 °C, 3 %, 9 %, and 15 % of the initial bound water, respectively, converted to free water.

中文翻译：

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膨润土中随温度变化的结合水变性的定量研究


饱和粘土中的温度升高会改变物理化学粘土-水相互作用，并可能导致结合水转化为游离水。这些变化会显著影响粘土的物理、化学和工程特性，这些特性对于岩土工程和地质工程至关重要，并且可以最大限度地降低膨胀粘土区域的风险。然而，在文献中量化这种现象仍然具有挑战性。本研究提出了一种强大的实验方法，用于量化粘土中结合水的热诱导转化，为控制其热机械行为的机制提供了有价值的见解。提出了一种新的实验方法来量化在 20 至 50 °C 温度下的粘土系统中的简并结合水含量。 该研究采用虹吸原理来检查高温下粘土系统的体积变化，重点是测量结合水到自由水的转化率。这种方法考虑了土壤成分和限制玻璃圆柱体的热膨胀，以及潜在的蒸发损失。为了验证设置的准确性，使用标准渥太华沙子进行了校准测试，其结合水可以忽略不计。在测量系统误差后，校准主要结局。结果表明，在 30 °C、40 °C 和 50 °C 时，初始结合水的 3 %、9 % 和 15 % 分别转化为游离水。