Addressing Clay Mineralogy Effects on Performance of Chemically Stabilized Expansive Soils Subjected to Seasonal Wetting and Drying

Abstract

This is an author-produced, peer-reviewed version of this article. The final, definitive version of this document can be found online at Journal of Geotechnical and Geoenvironmental Engineering, published AbstractPremature failures in chemically stabilized expansive soils cause millions of dollars in maintenance and repair costs. One of the reasons for these failures is the inability of existing stabilization design guidelines to consider the complex interactions between clay minerals and the stabilizers. It is vital to understand these complex interactions, as they are responsible for the strength improvement and swell/shrink reduction in these soils, in turn affecting the overall health of the infrastructure. Hence, this research study examined the longevity of chemically stabilized expansive soils subjected to wetting/drying conditions with a major focus on clay mineralogy. Eight different natural soils with varying clay mineralogy were subjected to wetting/drying durability studies after stabilizing with chemical additives including quicklime and cement. Performance indicators such as volumetric strain and Unconfined compressive strength trends were monitored at regular intervals during the wetting/drying process. It was observed that clayey soils dominant in the mineral Montmorillonite were susceptible to premature failures. It was also noted that soils dominant in other clay minerals exhibited early failures at lower additive contents. Also, an attempt was made for the first time to address the field implications of the laboratory studies by developing a correlation that predicts service life in the field based on clay mineralogy and stabilizer dosage.

Alteration of the Hydromechanical Performances of a Stabilized Compacted Soil Exposed to Successive Wetting–Drying Cycles

“…Some in situ investigations of lime stabilised roads showed qualitatively that exposure to climatic conditions can have a negative impact on the behaviour of stabilised soils in the long term (Cuisinier and Deneele, 2008;Gutschick, 1978;Kelley, 1988). This was also evidenced through laboratory studies that showed that successive wetting/drying periods (Alavez-Ramirez et al, 2012;Chittoori et al, 2018;Guney et al, 2007;Khattab et al, 2007;Neramitkornburi et al, 2015;Rao et al, 2001) or repeated freezing/thawing (Bin-Shafique et al, 2010;Consoli et al, 2017;Dempsey and Thompson, 1968), etc.) may lead to a significant decrease of the treated soil hydromechanical characteristics.…”

The Durability of Lime and Rice Husk Ash Improved Expansive Soil

“…Based on the Chittoori BCS et al [21] study, all the soils dominated by clay minerals will fail early in the lower additive content. The content of montmorillonite determines the technical characteristics of stabilized soil.…”

Combined effect of mineralogical and chemical parameters on swelling behaviour of expansive soils

“…In connection to this, Sun et al 28 predicted the swelling pressure of bentonite and sand mixes by developing empirical relationship between void ratio and swelling pressure. In similar lines, Chittoori et al 29 studied the effect of clay mineral montmorillonite on the performance of chemically stabilized soils, and Mehta and Sachan 30 investigated the influence of mineralogy on mechanical behaviour of expansive soils. More deeply, Tahasildar et al 11 studied the influence of montmorillonite on swelling behaviour with limited set of data.…”