Procedures for Stabilizing Non-Dispersive Clay Soils

Question: How to stabilize clay soil to make clay soil non dispersive. Answer: ` the non- dispersive characteristics of the clay soil. (Indraratna, 1991) The following description cites some of the materials being used to stabilize the dispersive clay soils. Most traditionally there are techniques of using straw and sand to stabilize the clay soils. However with time there happened several changes in the procedures like usage of chemical constituents to stabilize the clay soils found to be very versatile. Some of the materials like acids, enzymes, lingo sulfonates are being used to stabilize the clay soils. Other applications like petroleum emulsions, polymers are also equally used for stabilization. Tree resins are also found to be successful in stabilizing the clay soils (Jafari, 2012). Straw and plant fibers are used for reinforcement of the clay soils. They act as reinforcement agents. All type of straw like that from wheat, rye, barley etc. are used for reinforcement. Other fibrous plant materials like sisal, hemp, elephant grass, coir (Coconut fiber), and bagasse (sugar cane waste) etc. can be used successfully for stabilizing the clay soils. Usage of cement products like soil cement, rammed earth techniques, lime mixing etc. are quite useful techniques in stabilizing the non-dispersive clay soil. In most of the cases the substances used do generate a hydrophobic surface and mass of the same, which will subsequently works on to prevent the ingress of water into the treated soil layer. This will help to prevent the failure of constructions like road failures when constructed on the non- dispersive clay soil (Vaile et al, 2013). Recent and improved techniques of stabilizing clay soil include styrene acrylic polymer, usage of long crystals for creating a closed cell formation etc. are all equally useful in stabilizing the clay soil. Clay soil with liquid limits upto 40% more can be stabilized only with lime. The mechanism consists of lime reaction with the clay particles and subsequent formation of a binder. Quick lime (Cao), produced by burning of limestone can also be used for stabilizing actions. However the process is to be close monitored, precautions need to be taken for crushing the quicklime before using for stabilizing purpose. Hydrated slaked lime, prepared by adding water to quick lime can also be used for similar applications. The milk of lime, slaked lime with excess water or as lime putty can be used for stabilization purpose (Swain, 2015). The method used for stabilization actually depends on the type of the application and the end purpose. For example insitu stabilization, deep stabilization, dry stabilization as well as wet stabilization are some of the several methods used for soil stabilization purpose. The success and efficiency of the process depends on the procedures like how best the stabilizers are mixed and how much minimum amount of the stabilizers are used in the process. The best procedure is that exhibits the best performance and utilizes the minimum amount of the stabilizer material. Selection of the best stabilizer and the right procedure for stabilization depends on the application and the exact physical properties of the soil clay as well. References: Indraratna, B., Nutalaya, P., Kuganenthira, N. (1991). Stabilization of a dispersive soil by blending with fly ash. Quarterly Journal of Engineering Geology and Hydrogeology, 24(3), 275-290. Jafari, H. R., Rad, M. H., Hassanlou, M. R. (2012). Evaluating Chemical Stabilization of Dispersive Clay by Aluminum Sulfate (Alum). World Applied Sciences Journal, 18(5), 613-616. Vakili, A. H., Selamat, M. R., Moayedi, H. (2013). Effects of using pozzolan and portland cement in the treatment of dispersive clay. The Scientific World Journal, 2013. Swain, K. (2015). Stabilization of Soil Using Geopolymer and Biopolymer (Doctoral dissertation, NATIONAL INSTITUTE OF TECHNOLOGY, ROURKELA).