Swelling Pressure Control in Expansive Soil–Lime Mixtures: Influence of Porosity and Lime Content
摘要
Expansive soils can cause drawbacks to infrastructure and lightweight buildings due to the volumetric variation they undergo upon moisture content changes. Chemical stabilisation with calcium-based materials quickly overcomes such inconveniences. Still, no rational methodology exists that associates the swelling pressure (Ps) to dosage characteristics of the amended soil, such as dry density and hydrated lime content. Therefore, this paper utilises the adjusted porosity/volumetric hydrated lime content index, defined as adjusted – η/(Liv)a, to describe the relationship between Ps and unconfined compression strength (qu) of compacted expansive soil-hydrated lime blends. A series of one-dimensional swelling pressure tests and unconfined compression tests were carried out on specimens compacted with three dry unit weights (14, 15, and 16 kN/m3) and hydrated lime contents (2, 3, and 4%), following a full factorial design approach. Additionally, the swelling of the compacted natural soil was assessed as a reference. All the data can be adequately described by a single power-law relationship that relates the Ps and qu with the η/Liv index. This highlights the influences of porosity and hydrated lime content on the Ps and qu response. This response was later corroborated by an analysis of variance (ANOVA). For Ps in particular, this proposed approach was validated for other expansive soils treated with lime, using results from literature. In summary, this work presents a rational and practical framework for assessing the influence of key parameters on the swelling pressure of expansive soils stabilised with hydrated lime.