介质环境中阳离子和酸碱度变化对粘土分散性的影响

采用碎块试验研究介质环境中阳离子和酸碱度变化对粘土分散性的影响。试验结果表明,在Na＋浓度为8×10^-4-1×10^-2mol/L范围内和pH约大于10.4的介质环境条件下,非分散性土表现特征为分散性;而Na^＋浓度在该浓度范围外时或阳离子为其他离子介质环境条件下,非分散性土表现特征为非分散性。研究表明：土体产生分散性的必要条件是土体中含有较多的钠离子和呈强碱性;蒙脱石含量高低不是分散性土的必要条件。

Effect of Cation and pH Value on Dispersivity of Clay in the Medium Environment

The effect of the cation and pH value on the dispersivity of clay in the medium environment is studied by the crumb test. The results showed that the non-dispersive soil was changed to the dispersive soil if the medium environment had the 8×10~(-4)～1×10~(-2) mol/L sodium and the pH value＞10.4;The non-dispersive soil had the non-dispersive properties if the sodium content was out this content or the medium environment had other cations. The study indicated that the nesessary condition for creating the dispersive mechanisms of soil lie in the more sodium and the stronger alkalinity(pH＞8.5) in the soil;it was not the necessary condition that how much montmorillonite was contained to cause soil dispersive.