HITEC Influence of temperature on clay-based material behaviour

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F24%3A00382916" target="_blank" >RIV/68407700:21110/24:00382916 - isvavai.cz</a>

Result on the web

<a href="https://www.ejp-eurad.eu/publications/eurad-d78-hitec-influence-temperature-clay-based-material-behaviour" target="_blank" >https://www.ejp-eurad.eu/publications/eurad-d78-hitec-influence-temperature-clay-based-material-behaviour</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

HITEC Influence of temperature on clay-based material behaviour

Original language description

his report presents an overview of Task 3.2 progress in the HITEC work package of the European Joint Programme on Radioactive Waste Management programme. The objectives of this task are focussed around evaluating the behaviour of clay buffer materials at high temperature. The findings are expected to inform the feasibility of designing geological disposal facilities to operate at elevated temperature conditions. The objectives of this work are described, followed by an overview of progress on this task from each project partner. An emphasis is given on materials used, research planned, laboratory setups used and results available to date. Testing is focussed on a range of bentonites including: Mx80, Kunipia-G, FEBEX, BCV, Bara-Kade, PBC. Finally, general conclusions from resulting from this work are also provided, with an emphasis on the impacts for repository design, remaining uncertainties and recommendations for future work. Despite delays resulting from the Covid-19 crisis, substantial progress has been made in the development and construction of a wide range of experimental apparatus within this task. Progress has been made in the development of imaging methodologies and preliminary observations indicate that the uptake of water is sensitive to elevated temperatures. Relationships delineated within Task 3.2 include: (i) the observation of swelling pressure and permeability as a function of temperature for various dry densities, swelling strains, chemical states and conditions and (ii) water retention curves, as function of temperature. For the materials and conditions tested, an influence of elevated temperature on water retention capacity has been observed. Multiple test programmes, in both Ca- and Na-bentonite have also found evidence that, whilst changes to hydraulic permeability are perhaps less significant, swelling pressure can be substantially impacted by elevated temperatures. Further work to consider the mechanisms and consequences of this behaviour for repository design are recommended as a result. The extensive datasets generated by this Task 3.2 will enable the parameterisation, modification and validation of numerical simulations to more accurately represent the thermo-hydro-mechanical behaviour of bentonite at elevated temperatures.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20101 - Civil engineering

Project

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Continuities

R - Projekt Ramcoveho programu EK

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů