Key Parameter for Swelling Control of Compacted Expansive Fine-Grained Soil–Lime Blends

Fine-grained soils that expand when in contact with water can be a major issue in some geotechnical situations, but the soil can be stabilized through chemical means by hydrated lime incorporation. However, there is not yet any rational dosage methodology that combines the effects of both lime content and porosity of the treated soil specimen to predict its behavior regarding swelling. Thus, the present research intends to assess the one-dimensional swelling response of an expansive fine-grained soil stabilized with lime. For this purpose, compacted soil–lime blends were molded with three distinct amounts of lime (2%, 4%, and 6%), compacted to three different dry unit weights (14, 15, and $16\mathrm{kN}/{\mathrm{m}}^3$) and tested after 3 h of curing. The results show that lime content, porosity, and their interaction are statistically significant in altering the swelling behavior of the compacted blends. Moreover, both can be combined through the adjusted porosity/lime index and related to the one-dimensional swelling. As a result, a single unique relationship could be established between the swelling and the proposed index with a coefficient of correlation ($R^2$) of 96%. This approach was also successfully employed in other fine-grained soils treated with lime as validation.