Characterization of dispersive problematic soils and engineering improvements: A review

Dispersive soils, as a problematic soil for different applications, are prevalent over wide areas of the world, especially arid and semi-arid regions. The tendency for dispersive erosion in a given soil depends on variables including mineralogy and chemistry of the clay, as well as dissolved salts in the water in soil pores and in the eroding water. In order to recognize a dispersive clay or to measure dispersion potential, researchers have recommended field observations (such as colour and variety of eroded forms), physical tests (such as double hydrometer, pinhole, and crumb test), chemical measurements ( such as Sodium adsorption Ration-SAR, Exhchangeable Sodium Percentage-ESP, and Cation Ratio of soil structural stability-CROSS ), and Mechanical tests (such as Atterberg limits, compression strength, Shear strength, compaction, density). Structures can be built with dispersive clay if certain precautions are taken. The dispersive soils were improved by several solutions like chemical reaction, mechanical reinforcement, and a combination of chemical and mechanical methods. The most common method is using of chemical materials with the majority of lime, gypsum and cement as chemical amendments.