Chemical stabilization involves the use of chemical agents for initiating reactions within the soil for modification of its geotechnical properties. Cement and lime stabilization have been the most common stabilization methods adopted for soil treatment. Cement stabilization results in good compressive strengths and is preferred for cohesionless to moderately cohesive soil but loses effectiveness when the soil is highly plastic. Lime stabilization is the most preferred method for plastic clays; however, it proves to be ineffective in sulphate rich clays and performs poorly under extreme conditions. With such drawbacks, lots of researches have been undertaken to address the issues faced with each stabilization method, in particular, the use of solid wastes for soil stabilization. Solid waste reuse has gained high momentum for achieving sustainable waste management in recent times. Research has shown that the use of solid wastes as additives with and replacement for conventional stabilizers has resulted in better results than the performance of either individually. This review provides insight into some of the works done by earlier researchers on lime/cement stabilization with industrial wastes as additives and helps to form a sound platform for further research on industrial wastes as additives to conventional stabilizers.

The study involved utilization of an industrial waste, Phosphogypsum (PG), as an additive to lime stabilization of an expansive soil. Three lime dosages, namely, initial consumption of lime (ICL), optimum lime content (OLC), and less than ICL (LICL), were identified for the soil under study for stabilizing the soil. Along with lime, varying doses of PG were added to the soil for stabilization. The effect of stabilization was studied by performing index tests, namely, liquid limit, plastic limit, shrinkage limit, and free swell test, on pulverized remains of failed unconfined compression test specimens. The samples were also subjected to a microstructural study by means of scanning electron microscope. Addition of PG to lime resulted in improvement in the plasticity and swell-shrink characteristics. The microstructural study revealed the formation of a dense compact mass of stabilized soil.

The study involved investigating the performance of ordinary Portland cement (OPC) stabilized soil blocks amended with sugarcane bagasse ash (SBA). Locally available soil was tested for its properties and characterized as clay of medium plasticity. This soil was stabilized using 4% and 10% OPC for manufacture of blocks of size 19 cm × 9 cm × 9 cm. The blocks were admixed with 4%, 6%, and 8% SBA by weight of dry soil during casting, with plain OPC stabilized blocks acting as control. All blocks were cast to one target density and water content followed by moist curing for a period of 28 days. They were then subjected to compressive strength, water absorption, and efflorescence tests in accordance with Bureau of Indian standards (BIS) specifications. The results of the tests indicated that OPC stabilization resulted in blocks that met the specifications of BIS. Addition of SBA increased the compressive strength of the blocks and slightly increased the water absorption but still met the standard requirement of BIS code. It is concluded that addition of SBA to OPC in stabilized block manufacture was capable of producing stabilized blocks at reduced OPC content that met the minimum required standards.

The study dealt with the effect of addition of sugarcane bagasse ash (BA) on the strength development of a lime stabilized expansive soil. Unlike previous investigations with combinations of lime and BA, this study compares the effect of lime contents determined by scientifically established procedures and the effect of BA on the stabilization of lime at different proportions with additional microstructural investigations. The minimum lime content required for stabilization known as initial consumption of lime (ICL) was determined using the Eades and Grim pH test as 5.5%. The optimum lime content (OLC) was determined using unconfined compression strength (UCS) tests as 7%. Another lime content less than ICL was randomly adopted as 3%. The three lime contents were mixed with 0.25%, 0.5%, 1%, and 2% BA. UCS samples of dimension 38 mm × 76 mm were prepared at a fixed dry density and moisture content and cured for periods of 2 hours (0 days), 3, 7, 14, and 28 days to study the development of strength and effect of BA. Mineralogical and microstructural analyses were performed on the pulverized UCS samples after failure. The results revealed that the addition of BA increased the immediate, early, and delayed strength of lime stabilized soil further, even when the lime content was lower than ICL. Addition of BA produced maximum immediate, early, and delayed strength gains of 58.3%, 20.7%, and 32.7%, respectively. Higher proportion of BA was required when lime content was above ICL, for maximum strength. Addition of BA resulted in better utilization of quartz in lime-soil reactions leading to formation of CSH and CAH minerals. A dense compact matrix was seen on analyzing the microstructure of the stabilized soil composite.

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