Influence of Sodium and Lithium Monovalent Cations on Dispersivity of Clay Soil

Parameswaran, T G and Sivapullaiah, P V (2017) Influence of Sodium and Lithium Monovalent Cations on Dispersivity of Clay Soil. In: JOURNAL OF MATERIALS IN CIVIL ENGINEERING, 29 (7).

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Abstract

Exchangeable sodium ions are widely reported to be the principal reason for the dispersivity of soils. From fundamental theoretical considerations, several other factors such as pH, cation exchange capacity, mineralogy, electrolyte concentration, and dissolved salts can affect the attractive/repulsive forces in soils and hence are considered to have a significant role in assessing the dispersivity of soils. To assess the influence of these parameters, a known dispersive soil was treated with sodium hydroxide and lithium hydroxide and the dispersivity was assessed. It was confirmed that the effects of these factors on dispersivity are manifested through the amount of hydration of the adsorbed monovalent cations. Because the inner hydration shell of adsorbed monovalent cations is larger than those of higher-valency ions, dispersivity is related to the presence of monovalent cations alone. It was also established that within the monovalent cations, the size of hydrated ions can vary and can influence the dispersivity of the soil. The dispersivity of soils increased with a reduction in the size of the ions. The increase in repulsive force (causing dispersion) due to the reduction in the size of the cation is explained through diffuse double layer theory. A complete philosophy of dispersion is proposed in light of the current experimental results.

Item Type:	Journal Article
Publication:	JOURNAL OF MATERIALS IN CIVIL ENGINEERING
Additional Information:	Copy right for this article belongs to the ASCE-AMER SOC CIVIL ENGINEERS, 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	25 May 2017 08:52
Last Modified:	25 May 2017 08:52
URI:	http://eprints.iisc.ac.in/id/eprint/57033

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