The impact of chemical additives on the engineering properties of expansive soils has been studied in the past few years; however, the swelling properties as well as mineralogical and microstructural characteristics of expansive clay soils stabilized with NaCl solutions have not been clearly studied. This research work aims at investigating the expansion behavior of the studied clay soil before and after the treatment with a NaCl solution. It also aims to interpret the change in the soil geotechnical properties by monitoring the mineralogical and microstructural alterations. The treatment was performed with different NaCl doses (2.5–12.5%) for different curing times using various water amounts. The mineralogical and microstructural composition of NaCl-stabilized soil samples were analyzed by means of x-ray diffraction analysis, thermal analysis, and scanning electron microscopy. The test results indicated that the NaCl solution reduced the soil swelling in the short term significantly. The amount of water used in NaCl treatment considerably affected its performance. The mineralogical alteration of disappearance of the montmorillonite mineral from the composition of the NaCl-stabilized soil sample interpreted the reduction in the soil swelling in the short term. The 90 days, 12.5% NaCl-stabilized soil sample had densely packed cement block-like microstructure. This resulted from the binding of the soil clay aggregates by the newly formed cementitious products.

在过去的几年中，已经研究了化学添加剂对膨胀土工程特性的影响。然而，用NaCl溶液稳定的膨胀黏土的膨胀特性以及矿物学和微观结构特征尚未得到清楚的研究。这项研究工作旨在调查研究的粘土在NaCl溶液处理之前和之后的膨胀行为。它还旨在通过监测矿物学和微观结构的变化来解释土壤岩土特性的变化。使用不同的水量，以不同的NaCl剂量（2.5–12.5％）对不同的固化时间进行处理。NaCl稳定化土壤样品的矿物学和微观结构组成通过X射线衍射分析，热分析，和扫描电子显微镜。试验结果表明，NaCl溶液在短期内显着降低了土壤溶胀。NaCl处理中使用的水量极大地影响了其性能。从NaCl稳定化的土壤样品组成中，蒙脱石矿物消失的矿物学变化解释了短期内土壤溶胀的减少。90天，氯化钠浓度为12.5％从NaCl稳定化的土壤样品组成中，蒙脱石矿物消失的矿物学变化解释了短期内土壤溶胀的减少。90天，氯化钠浓度为12.5％从NaCl稳定化的土壤样品组成中，蒙脱石矿物消失的矿物学变化解释了短期内土壤溶胀的减少。90天，氯化钠浓度为12.5％-稳定的土壤样品具有紧密堆积的水泥块状微观结构。这是由于新形成的胶结产物对土壤粘土骨料的粘合作用所致。