温度循环变化下高庙子膨润土持水特性

Water Retention Property of GMZ Bentonite under Temperature Cycles

采用高精度温湿度传感器直接量测吸力的方法,研究了高庙子膨润土在温度循环变化条件下的持水特性。试验结果表明:高庙子膨润土的持水能力随温度升高而下降,温度对持水曲线的影响与含水率相关,含水率越高,温度影响越显著;在温度循环变化过程中吸力呈现出滞后性,对于低含水率试样,降温段吸力高于升温段吸力,而对于高含水率试样,降温段吸力则低于升温段吸力。不同含水率下温度及其循环对持水曲线影响的差异性,与膨润土中随温度变化层间水与毛细水之间的转化密切相关。

Water retention curve of GMZ bentonite under temperature cycles was studied based on the suction measurement method utilizing highly precisive humidity sensors. The water retention capacity of GMZ bentonite decreased with an increase in temperature. The degree of the temperature＇ s effects on water retention curve depended on water content, that was, the higher water content, the more notable temperature effects. Hysteresis of suction changes in temperature cycles was observed. At low water contents, suctions at the cooling stage were higher than that at the heating stage, while the suctions at the cooling stage were lower in samples with high water content. The dependence of the temperature＇ s effects on water content was mainly due to the conversion from the interlayer water to the capillary water within the temperature elevation.