膨润土复合材料渗透性与微观结构研究

Permeability and microstructure of bentonite composite materials

文章通过室内变水头渗透试验与微观电镜扫描试验对膨润土缓膨特性进行研究,探究葡萄糖溶液对膨润土的缓膨抑制作用。试验结果表明:随着静置时间的增加,葡萄糖溶液配制的膨润土复合材料试样的渗透系数逐渐减小,并且葡萄糖溶液浓度越大,试样渗透系数减小的越明显;当葡萄糖溶液浓度为8%~10%时,复合材料渗透系数会随着试样静置时间的增加,呈现出明显减小的趋势,并且膨润土含量越大这种影响作用越显著,渗透系数可达10-8数量级;电镜试验中随着试样静置时间的增加,用葡萄糖溶液配制的膨润土复合材料试样微孔隙逐渐减少,微观结构致密性逐渐增加。通过宏观渗透试验和微观电镜扫描试验得出葡萄糖溶液对膨润土的膨胀具有缓膨抑制作用,并且当溶液浓度在8%~10%时对膨润土的缓膨抑制作用最优。

To study the effect of the glucose solution on slowing the expansion of bentonite, we utilized indoor falling head permeability test and SEM observation in this work. The result shows that the permeability coefficient of bentonite composite sample with glucose solution is gradually reduced with the increasing specimen stock-still time. Moreover, the permeability coefficient of sample decreases with the glucose concentration increased. When the concentration of glucose solution is8%to 10 %, the composite sample permeability coefficient shows a significant decreasing trend with the increasing standing time, the higher content of bentonite, the greater of this effect, and the penetration coefficient decreases even to 10-8 orders of magnitude; With the increasing specimen stock-still time, the microstructure of composite sample with different concentration of glucose solution gradually compacted, and micro pore gradually reduced. According to the experiments of macroscopic permeability test and micro electron microscope scanning test, glucose solution can slow the expansion of bentonite, and when the solution concentration is8%to 10 %, the inhibition effect of slowing swelling bentonite is optimal.