Compressibility and hydraulic conductivity of a chemically treated expansive clay

Abstract

The paper presents a series of laboratory tests and evaluates the effect of lime and fly ash on the compressibility and hydraulic characteristics of an expansive soil in Cyprus. The tests were performed at different percentages of lime (0–7%) and fly ash (15 and 25%) by dry weight of soil, and additional tests were also performed on soils treated with 15% fly ash plus 3% lime. Previously published research reveals that few data are available concerning the compressibility and hydraulic conductivity of lime-treated soils. The results of this study indicate an increase in the vertical effective yield stress (apparent preconsolidation pressure) and a decrease in the compressibility characteristics of the treated soils. Moreover, unlike some of the findings in the literature, higher hydraulic conductivity values were obtained with time. This finding has been substantiated by the reduced cation exchange capacity (CEC) values, which indicate that the pozzolanic reaction causes the soils to become more granular in nature, resulting in higher hydraulic conductivity.Key words: cementation, compressibility, fly ash, hydraulic conductivity, lime.

Microstructural and Mineralogical Characterization of Clay Stabilized Using Calcium-Based Stabilizers

“…The rate of exchange depends on clay type, solution concentrations and temperature (Gomez, 2009). In soil stabilization studies, CEC values have been used to a limited extent to explain the effectiveness of soil stabilization (Nalbantoglu and Tuncer, 2001;Al-Rawas et al, 2002;Nalbantoglu, 2004;Gomez, 2009).…”

“…It can be seen that lime and CFA had the highest and the lowest SSA values, respectively. A higher SSA indicates more reactivity of additive (Nalbantoglu and Tuncer, 2001;Sreekrishnavilasam et al, 2007).…”

Effets de sollicitations hydriques cycliques sur le gonflement d’un sol argileux traité à la chaux

“…Le traitement à la chaux permet aussi de réduire, voire de supprimer, le gonflement des sols argileux (Brandi 1981 ;Nalbantoglu et Tuncer, 2001 ;Rao et Thyagaraj, 2003). Ainsi, le traitement à la chaux pour rait être intéressant pour prévenir le gonflement des sols argileux dans le cadre de leur emploi en terras sement.…”

Behavior of a Lime-Treated Expansive Soil

“…ratio between height increase due to wetting to initial height, of an expansive soil reduced from 34.5% to about 26.5% in specimens mixed with 10% of limestone, and from 34.5% to about 1% in specimens with 10% of hydrated lime. Also, Nalbantoglu & Tuncer (2001) found that the swelling potential was drastically reduced from 20% for the untreated specimen to 1.5% when treated with 2% of lime with no curing time.…”

“…In fact, some researchers have shown that lime treatment may reduce the swelling potential of expansive soils (Holt et al, 2000;Al-Rawas et al, 2005;Panjaitan, 2014, Schanz & Elsawy, 2015, Nalbantoglu & Tuncer, 2001). For instance, Schanz & Elsawy (2015) concluded that the swelling potential, i.e.…”