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Transport Phenomena in Smectite Clay Explained by Considering Microstructural Features

Published online by Cambridge University Press:  10 February 2011

Roland Pusch
Roland Pusch*
Affiliation:
Geodevelopment AB, Clay Technology AB
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Abstract

The microstructure of clays controls their transport properties. This is concluded from comparing microstructural parameter data with the hydraulic conductivity and the ion diffusive transport capacity. Illitic clays contain a number of interacting open voids with a high flow capacity while natural smectite-rich clays are more homogeneous with smaller voids and a lower hydraulic conductivity than illitic clays with the same density. Artificially prepared smectitic clays, like those proposed for embedding canisters with highly radioactive waste, have a higher conductivity than natural clays with the same smectite content because the microstructural homogeneity of the artificial clays is less good.

The anion diffusive transport capacity of smectite-rich clays with high density is much lower than that of clays with low density in contrast to the cation diffusive capacity. This is explained by using quantitative microstructural data.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 506: Symposium – Scientific Basis for Nuclear Waste Management XXI , 1997 , 439
Copyright
Copyright © Materials Research Society 1998

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References

REFERENCES

1 Pusch, R, 1970. Clay microstructure. Document D:70. Nat Swed. Counc. Build. Res., Stockholm.Google Scholar
2 Pusch, R, 1971. Microstructural features of Pre-Quaternary clays. Acta Universitatis Stockholmiensis, Stockholm Contributions in Geology, Vol.XXIV: 1.Google Scholar
3 Pusch, R, 1978. Highly compacted bentonite as buffer substance. SKBF/KBS Technical Report Nr 74. SKB, Stockholm.Google Scholar
4 Pusch, R, Karnland, O, Hökmark, H, 1990. GMM - A general microstructural model for qualitative and quantitative studies of smectite clays. SKB Technical Report TR 90-43, SKB, Stockholm.Google Scholar
5 Pusch, R, Börgesson, L, Erlström, M, 1987. Alteration of isolating properties of dense smectite clay in repository environment as examplified by seven Pre-Quatemary clays. SKB Technical Report TR 87-29, SKB, Stockholm.Google Scholar
6 Pusch, R, Karnland, O, 1988. Geological evidence of smectite longevity. The Sardinian and Gotland cases. SKB Technical Report TR 88-26, SKB, Stockholm.Google Scholar
7 Brandberg, F, Skagius, K, 1991. Porosity, sorption and diffusivity data compiled for the SKB91 study. SKB Technical Report TR 91-16. SKB, Stockholm.Google Scholar
8 Muurinen, A, 1994. Diffusion of anions and cations in compacted sodium bentonite. Technical Research Centre of Finland, VTT Publications Nr 168.Google Scholar
9 Pusch, R, 1973. Influence of salinity and organic matter on the formation of clay microstructure. Proc. Int. Symp. Soil Structure. Chalmers Technical University, Dept. Soil Mech. a. Foundation EngineeringGoogle Scholar