Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-02T23:04:27.606Z Has data issue: false hasContentIssue false
  • English
  • Français

Swelling Pressures of Compacted Bentonite/Sand Mixtures

Published online by Cambridge University Press:  26 February 2011

M. N. Gray ,
S. C. H. Cheung  and
D. A. Dixon
M. N. Gray
Affiliation:
Atomic Energy of Canada Limited, Whiteshell Nuclear Research Establishment, Pinawa, Manitoba ROE ILO, Canada
S. C. H. Cheung
Affiliation:
Atomic Energy of Canada Limited, Whiteshell Nuclear Research Establishment, Pinawa, Manitoba ROE ILO, Canada
D. A. Dixon
Affiliation:
Atomic Energy of Canada Limited, Whiteshell Nuclear Research Establishment, Pinawa, Manitoba ROE ILO, Canada
Get access

Abstract

Compacted bentonitic clay/sand mixtures are being considered for use as buffer materials in the Canadian concept for nuclear fuel waste disposal. This paper describes a laboratory study of the swelling pressures that develop in statically compacted, air-dry specimens of mixtures of sodium bentonite and silica sand as they are saturated with double-distilled, deionized water. The results are interpreted with the aid of scanning electron microscope observations of the soils' structures.

It is shown that the sand acts as an inert filler material, and swelling pressures are controlled by a parameter termed the effective clay dry density, γC, defined as the ratio of the mass of clay to the combined volume of the claq plus voids in the mixture. A threshold value of γC exists below which swelling pressures can be expected to be isotropic. Above the threshold value of γC, pressures parallel to the axis of compaction can be expected to be greatgr than those perpendicular to it. This is related to a change in soil fabric as γC is increased above the threshold value. For the Canadian disposal concept, γC would probably be below the limiting value and swelling pressures of 2.5 MPS or less are expected. The swelling pressures are likely to be isotropic within a saturated buffer mass.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 44: Symposium N – Scientific Basis for Nuclear Waste Management VIII , 1984 , 523
Copyright
Copyright © Materials Research Society 1985

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

[1] Rosinger, E. L. and Dixon, R. S., Atomic Energy of Canada Limited Report, AECL-7793 (1982).Google Scholar
[2] Bird, G. W. and Cameron, D. J., Atomic Energy of Canada Limited Technical Record, TR-145 (1982).Google Scholar
[3] Oscarson, D. W. and Cheung, S. C. H., Atomic Energy of Canada Limited Report AECL-7812 (1983).Google Scholar
[4] Pusch, R., SKBF/KBS Technical Report 80–13, SKBF/KBS, Stockholm, Sweden, 1980.Google Scholar
[5] Wardrop, W. L.and Associates, Atomic Energy of Canada Limited Report, in preparation.Google Scholar
[6] Dixon, D. A., Gray, M. N., and Thomas, A. W., Symposium on Clay Barriers For Isolation of Toxic Chemical Wastes, Stockholm, Sweden. Elsevier Scientific, Publishing Co., Amsterdam, 1984.Google Scholar
[7] Quigley, R. M., Atomic Energy of Canada Limited Report, AECL-7827 (1984).Google Scholar
[8] Talbot, A. N. and Richart, F. E., Bulletin 137, Engineering Experimental Station, University of Illinois, 1923.Google Scholar
[9] Lambe, T. W., Soil Testing for Engineers, John Wiley and Sons, Toronto, 1951.Google Scholar
[10] Neville, A. M., Properties of Concrete, Pitman Publishing, London, 1980.Google Scholar
[11] Lambe, T. W. and Whitman, R. V., Soil Mechanics, John Wiley and Sons, Toronto 1951.Google Scholar
[12] van Olphen, H., An Introduction to Clay Colloid Chemistry, Interscience Publishers, 1963.Google Scholar
[13] Yong, R. N. and Warkentin, B. B., Soil Properties and Behavior, Elsevier Scientific Publishing Co., Amsterdam, 1976.Google Scholar