A sustainable utilization of waste foundry sand in soil stabilization: a review

Soil stabilization involves various techniques and processes to improve the properties of soil especially expansive soils as it is considered troublesome for civil engineering and other field works due to its diminished strength shrinkage and swelling properties. Therefore, it becomes imperative to inculcate certain traditional or non-traditional stabilizers to elevate the geotechnical properties of soil. Waste foundry sand is one such non-traditional stabilizer that has been utilized in the soil for the improvement of soil properties. This paper presents an overall review of the past studies carried out on soil stabilization using waste foundry sand. The results reveal Atterberg's limits, i.e., liquid limit; plastic limit decreases with the increase in the percentage of waste foundry sand in the mix. Specifically, the liquid limit undergoes a reduction within the range of 25-30%, while the plastic limit experiences a decrease within the range of 16-18% when the optimum percentage of waste foundry sand (20-30%) is added to expansive soils. Further, there is an increase of around 25-42% in unconfined compressive strength and around 50-80% in California bearing ratio values on adding optimum percentage of WFS. Therefore, a WFS content of 20-30% is recommended as the optimum choice for soil stabilization in clayey soils.