Strength behaviour of lime-treated soils in the presence of sulphate

Abstract

Lime has been used extensively to improve the shear strength of fine-grained soils. It has been recently reported that the presence of sulphate causes abnormal volume changes in lime-stabilized soil. The paper presents the strength behaviour of lime-treated montmorillonitic natural black cotton soil in the presence of varying sulphate contents after curing for periods of up to 365 days. Alteration of soil-lime reactions in the presence of sulphate affects the strength development by cementation. Consequently, the stress-strain behaviour effective stress paths of soil cured with sulphate are similar to those of normally consolidated soil rather than cemented soils. The reduction in shear strength due to a reduction in effective cohesion intercept occurs for lime-treated soil cured with sulphate for long periods. Résumé : La chaux a été abondamment utilisée pour améliorer la résistance des sols à grains fins. On a fait rapport récemment du fait que la présence de sulfate produit des changements anormaux de volume dans le sol stabilisé à la chaux. Cet article présente le comportement en résistance d'un sol organique noir naturel montmorillonitique traité à la chaux en présence de diverses teneurs en sulfate après des périodes de mûrissement allant jusqu'à 365 jours. L'altération des réactions sol-chaux en présence de sulfate affecte le développement de la résistance par cimentation. En conséquence, le comportement contrainte-déformation, les cheminements de contrainte effective du sol mûri avec le sulfate montrent un comportement de sol normalement consolidé plutôt que de sols cimentés. La réduction de la résistance au cisaillement due à la réduction de l'interception cohésion effective se produit pour le sol traité à la chaux mûrissant avec du sulfate pour de longues périodes

Role of gypsum on microstructure and strength of soil

“…However, several attempts have been made to address the effect of sulfate/gypsum on the engineering behaviour of soil treated with other additives such as lime, fly ash, ground-granulated blast furnace and so on. Sivapullaiah et al (2000) studied the strength behaviour of lime-treated montmorillonitic natural black cotton soil in the presence of varying sulfate contents after curing for periods of up to 365 d and reported that decrease in strength occurs after longer periods of curing. Ahmed and Ugai (2011) attributed the rapid deterioration in compressive strength for stabilised soil-gypsum under freeze-thaw action mainly to the change in the calcium sulfate hemihydrate to calcium sulfate hydrate by which the cementation property of recycled gypsum is lost.…”

Use of lime and cement treated soils as pile supported load transfer platform

“…These soils can be used as construction material (Bell, 1996). Although lime stabilizes the soil rapidly after the treatment, the mechanical properties and strength of soil change over a long period of time (Bell, 1996;Sivapullaiah et al, 2000). Kavak and Akyarlı (2007) present the influence of lime treatment on mechanical properties of clays with laboratory and in-situ tests.…”

Effect of Calcium Sulphate on the Geotechnical Properties of Stabilized Clayey Soils

“…For a similar class soil, Kinuthia et al [13] reported that the LL decreases from 73% to 71, 69 and 67% respectively with 1, 2 and 3% CaSO 4 .2H 2 O for 6%L addition. On the other hand, for the same class soil, Sivapullaiah et al [15] observed that the LL increases from 68% up to 70, 73 and 76% respectively with 0.5, 1 and 3% CaSO 4 for 6%L addition due to the chemical interaction between soil, L and CaSO 4 . However, for the RS stabilized with 8%L on curing for 1 day, the LL decreases from 54.9% to 54.2, 53.7 and 52% respectively with 2, 4 and 6% CaSO 4 .2H 2 O (Table 7).…”

“…Furthermore, the magnitude of damage caused by the ettringite depends on the soil nature, the type and the content of additives [3] and the concentration and the type of cation associated with the sulphate anion [13]. Indeed, the effects caused by the presence of different types of sulphates on the geotechnical properties of soils stabilized with additives have been investigated by several researchers [13][14][15][16][17][18][19]. 1 …”