Novel procedure for the estimation of swelling pressures of compacted bentonites based on diffuse double layer theory

Bharat, Tadikonda Venkata and Sivapullaiah, Puvvadi Venkata and Allam, Mehter M (2013) Novel procedure for the estimation of swelling pressures of compacted bentonites based on diffuse double layer theory. In: Environmental Earth Sciences, 70 (1). pp. 303-314.

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Abstract

Bentonite clays are proven to be attractive as buffer and backfill material in high-level nuclear waste repositories around the world. A quick estimation of swelling pressures of the compacted bentonites for different clay-water-electrolyte interactions is essential in the design of buffer and backfill materials. The theoretical studies on the swelling behavior of bentonites are based on diffuse double layer (DDL) theory. To establish theoretical relationship between void ratio and swelling pressure (e versus P), evaluation of elliptic integral and inverse analysis are unavoidable. In this paper, a novel procedure is presented to establish theoretical relationship of e versus P based on the Gouy-Chapman method. The proposed procedure establishes a unique relationship between electric potentials of interacting and non-interacting diffuse clay-water-electrolyte systems. A procedure is, thus, proposed to deduce the relation between swelling pressures and void ratio from the established relation between electric potentials. This approach is simple and alleviates the need for elliptic integral evaluation and also the inverse analysis. Further, application of the proposed approach to estimate swelling pressures of four compacted bentonites, for example, MX 80, Febex, Montigel and Kunigel V1, at different dry densities, shows that the method is very simple and predicts solutions with very good accuracy. Moreover, the proposed procedure provides continuous distributions of e versus P and thus it is computationally efficient when compared with the existing techniques.

Item Type:	Journal Article
Publication:	Environmental Earth Sciences
Publisher:	Springer
Additional Information:	Copyright of this article belongs to Springer.
Keywords:	Bentonite Clays; Swelling Pressures; Diffuse Double Layer Theory; Gouy-Chapman Method
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	10 Oct 2013 05:23
Last Modified:	10 Oct 2013 05:23
URI:	http://eprints.iisc.ac.in/id/eprint/47480

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