Skip to Main Content
Book Chapter

The gas permeability, breakthrough behaviour and re-sealing ability of Czech Ca–Mg bentonite

By
Jan Smutek
Jan Smutek
Centre of Experimental Geotechnics, Faculty of Civil Engineering, Czech Technical University in Prague, Thakurova 7, 166 29 Prague 6, Czech Republic
Search for other works by this author on:
Lucie Hausmannova
Lucie Hausmannova
Centre of Experimental Geotechnics, Faculty of Civil Engineering, Czech Technical University in Prague, Thakurova 7, 166 29 Prague 6, Czech Republic
Search for other works by this author on:
Jiri Svoboda
Jiri Svoboda
Centre of Experimental Geotechnics, Faculty of Civil Engineering, Czech Technical University in Prague, Thakurova 7, 166 29 Prague 6, Czech Republic
Search for other works by this author on:
Published:
January 01, 2017

Abstract

The study’s objectives were to test the gas permeability of unsaturated compacted bentonite, the gas-breakthrough behaviour of saturated bentonite, and the re-sealing ability compared with the material’s dry density, hydraulic conductivity and swelling pressure. During the project’s pilot phase, a series of laboratory experiments were conducted on samples of two Czech Ca–Mg bentonites (Bentonite 75 and Cerny Vrch). The testing procedure, employing repeated hydration and gas-breakthrough test phases, simulated conditions within deep geological repositories for radioactive waste, wherein the buffer will be progressively hydrated from the surrounding host rock and loaded with pressure exerted by gases created within the repository.

It was found that the gas permeability of the bentonites tested was affected by dry density and, as with the two materials (FEBEX and MX-80) used for comparison, it correlated well with the accessible void ratio. Gas-breakthrough tests revealed correlations between time to breakthrough and both dry density and sample height. The recorded repeated test breakthrough times on the same samples varied, which implies that the pathways created are complex and differ for repeated gas-injection cycles. However, no systematic deterioration in sample properties was detected, thus indicating the extensive re-sealing ability of the materials tested.

You do not currently have access to this article.
Don't already have an account? Register

Figures & Tables

Contents

Geological Society, London, Special Publications

Radioactive Waste Confinement: Clays in Natural and Engineered Barriers

S. Norris
S. Norris
Radioactive Waste Management, UK
Search for other works by this author on:
J. Bruno
J. Bruno
Amphos 21, Spain
Search for other works by this author on:
M. van Geet
M. van Geet
ONDRAF/NIRAS, Belgium
Search for other works by this author on:
E. Verhoef
E. Verhoef
COVRA, The Netherlands
Search for other works by this author on:
Geological Society of London
Volume
443
ISBN electronic:
9781786203267
Publication date:
January 01, 2017

GeoRef

References

Related

A comprehensive resource of eBooks for researchers in the Earth Sciences

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal