Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-26T08:41:16.344Z Has data issue: false hasContentIssue false

Predicting the properties of bentonite-sand mixtures

Published online by Cambridge University Press:  09 July 2018

L. H. Mollins
Affiliation:
Department of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
D. I. Stewart
Affiliation:
Department of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
T. W. Cousens
Affiliation:
Department of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK

Abstract

One-dimensional swelling tests and hydraulic conductivity tests have been performed at vertical effective stresses up to 450 kPa on Na-bentonite powder and compacted sand/Na-bentonite mixtures (5, 10 and 20% bentonite by weight) to investigate the use of bentonite-improved soils for waste containment. It was found that bentonite powder swells to reach a final state described by a single straight line on a plot of void ratio against the logarithm of vertical effective stress, regardless of preparation technique. Swelling of sand/bentonite mixtures expressed in terms of the clay void ratio show a deviation from bentonite behaviour above a stress which depends on the bentonite content. Hydraulic conductivity data for bentonite and sand/bentonite mixtures indicate an approximately linear relationship between logarithm of hydraulic conductivity and logarithm of void ratio. A design model based on the clay void ratio, and the sand porosity and tortuosity is presented enabling the hydraulic conductivity of a mixture to be estimated.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alther, G., Evans, J.C., Fang, H.-Y. & Witmer, K. (1985) Influence of inorganic permeants upon the permeability of bentonite. Hydraulic Barriers in Soil and Rock, ASTM STP 874, 6473.Google Scholar
Bear, J. (1972). Dynamics of Fluids in Porous Media. America Elsevier publishing Company, Inc. New York, London, Amsterdam.Google Scholar
Casagrande, A. & Fadum, R.E. (1940). Notes on Soil Testing for Engineering Purposes: Soil Mech. Series No. 8, Harvard Graduate School of Engineering.Google Scholar
Cowland, J.W. & Leung, B.N. (1991) A field trial of a bentonite landfill liner. Waste Management and Research, 9, 277291.Google Scholar
Dixon, D.A. & Gray, M.N. (1985) The engineering properties of buffer material-research at Whiteshell Nuclear Research Establishment. Proc. 19th Information Meet. Nuclear Waste Management Program. AECL Technical Report, vol. 3, 513530.Google Scholar
Dixon, D.A, Gray, M.N. & Thomas, A.W. (1985) A study the of compaction properties of potential clay-sand buffer mixtures for use in nuclear fuel waste disposal. Eng. Geol. 21, 247255.Google Scholar
Dunn, R.J. (1985) Laboratory measurement of a fine grained soil fluid conductivity. Eng. Geol. 21, 215223.Google Scholar
Englehardt, W. VON & Tunn, W.L.M. (1955) Flow of Fluids Through Sandstones. Illinois State Geol. Survey - Cir, n 194, 16pp.Google Scholar
Garlanger, J.E, Cheung, F.K. & Tannous, B.S. (1987) Quality control testing for a sand-bentonite liner. Geotechnical Practice .for Waste Disposal, 488-499.Google Scholar
Graham, J., Gray, M.N., Sun, B.C.-C. & Dixon, D.A. (1986) Strength and volume change characteristics of a sand-bentonite buffer. Proc. 2nd Int. Conf. Radioactive Waste Management, Winnipeg, Manitoba, 188-194.Google Scholar
Hoeks, J., Glas, n., Hoekamp, J. & Ryhiner, A.H. (1987) Bentonite liners for isolation of waste disposal sites. Waste Management and Research, 5, 93–105.CrossRefGoogle Scholar
Irmay, S. (1965) Modé1es théoriques d’ écoulement dans. les corps poreux. RILEM Bul n 29, Dec. 1965, 3743.Google Scholar
Oscarson, D.W., Dixon, D.A. & Gray, M.N. (1990) Swelling capacity and permeability of an unprocessed and processed bentonitic clay. Eng. Geol. 28, 281289.Google Scholar
Porter, L.K., Kemper, W.D., Jackson, R.D. & Stewart, B.A. (1960) Chloride diffusion in soils as influenced by moisture content. Proc. Soil Sci. Soc. Amer., 24, 400403.Google Scholar
Schwarzendruber, D. (1962) Non-Darcy flow behaviour in liquid saturated porous media. J. Geophys. Res., 67, 52055213.Google Scholar
Shackleford, C.D. & Daniel, D.E. (1991) Diffusion in saturated soil. I: Background. J. Geotechn. Eng. 117, 467484.CrossRefGoogle Scholar
Terzagni, K. T. (1943). Theoretical Soil Mechanics. Wiley, New York.Google Scholar
Terzaghi, K. & Peck, R.B. (1967). Soil Mechanics in Engineering Practice. A Wiley International Edition.Google Scholar
Wu, J.Y. & Khera, R.P. (1990) Properties of a treatedbentonite/sand mix in contaminant environment. Pp. 47–59 in: Physico-Chemical Aspects of Soil and Related Materials, ASTM STP 1095, (Hoddinott, K.B. & Lamb, R.O., editors.), American Society for Testing and Materials.Google Scholar