温控高压实膨润土-砂混合物微观结构特征

Micro-Structural Characteristic of Highly Compacted Sand-Bentonite Mixtures at Different Temperatures

针对两种温度下不同位置处的恒体积渗透土样,利用压汞法研究了膨润土-砂混合物微观结构随温度和吸力的变化规律.结果表明:混合物微观结构呈现明显的双峰结构,水化和温度改变均会对其微观结构产生影响.随着吸力的降低集合体间孔隙量有减小的趋势,而集合体内孔隙量变化有限,使得样品的平均孔径逐渐减小.温度升高使得水化对土样微观结构的影响加剧.

Aimed to the permeated samplesof different positions at two temperatures and confined condi- tion, the microstructural changes with suctions and temperatures of sand - bentonite mixtures were studiedusing MIP method. Results indicate that the mien）structure of mixtures show the bio -modal structure. And the micro- structure is affected by suction and temperature change. As suction decreasing, the volume of marco - pore de- creases, while that of micro - pore increases limitedly. Therefor the mean pore size of samples gradually decrea- ses. Increased temperature enhances the effect of wetting on microstructure change.