Improvement of Geotechnical Properties of Heaving Soils Using Alternative Methods: A Review

In geotechnical practice, the shrink-swell behaviour of heaving soils causes significant damage to constructions. Soil stabilisation techniques helped to enhance the strength of problematic soils. Mechanical and chemical stabilisation techniques are generally used for these soils. Solid wastes are found abundantly worldwide, very few are recycled, but a significant amount of mismanaged solid wastes is produced globally every year. This study aims to review the applications of solid wastes, electrokinetic methods, and thermal treatment in heaving soil stabilisation and report their effectiveness and environmental issues. The method conducted in this study consists of synthesizing the precedent-relevant research works. The utilisation of solid wastes at different aspect ratios presented throughout this study can enhance various soil-engineering properties such as Atterberg limits, swell potential, Compaction characteristics, swelling pressure, shear strength, UCS, and CBR. The electrokinetic treatment method applied on heaving soil reduces the swelling potential (volume change) and significantly increases the soil strength. The thermal treatment method consists of heating the heaving soil at 600°C. The fine fraction reduces significantly. The plasticity index, linear shrinkage, and swelling potential can be reduced by about 30%, 15- 27%, and 15- 38% respectively. The gdmax and OMC can be enhanced by about 15%. The shear strength and CBR can be increased by about 30%. The utilisation of solid waste materials as a construction input helped achieve a dual purpose. The first is to reduce the adverse impact of the wastes on the geo-environment, and the second is substituting expensive stabiliser materials such as lime and cement since the cost of lime, cement, and chemical stabiliser increases due to energy and raw material. Nevertheless, the thermal treatment method increases the greenhouse gases responsible for global warming.