BEACON - Bentonite Mechanical Evolution
Begin of project: June 1, 2017
End of project: May 31, 2022
Status of project: July 1, 2021
The BGR was one among 25 partners from 10 countries who were involved in the EU funded Project „BEACON - Bentonite Mechanical Evolution“, during 2017-2022, focusing mainly on research in constitutive model development, model validation and experimental investigations into the hydro-mechanical behavior of the geotechnical barrier material Bentonite.
Repository concepts in clay and crystalline rock rely on a multi-barrier concept for radionuclide containment. This concept uses bentonite because of its swelling property under water uptake as buffer and backfill material. The project was aimed to improve the state-of-the-art of process- and system-understanding and of the mechanical models used in simulating transient coupled hydro-mechanical processes in bentonite. The main goal here was to develop models to describe the process of homogenization of bentonite given an initial heterogeneous distribution of bentonite properties.
The model development, simulation and experimental activities within the project were also accompanied by knowledge dissemination activities such as training courses and civil society interaction. Experience in past research projects (e.g. B. HE-E (heater test) in Mt. Terri, Task Force on Engineered Barrier Systems (Task Force on EBS), the international project DECOVALEX) was the starting point in the activities of the BGR in the project. The BGR was involved in Work Packages (WPs) 3 and 5.
Figure 1: Bentonite is a heterogeneous material capable of swelling, whose behaviour is treated with the theory of porous media (l). An inherent feature of the newly developed numerical model now represents the micro structure observed in the bimodal pore-size distribution
Source: BGR
In WP3, the BGR developed an improved constitutive model for swelling porous media with a bimodal pore-size distribution (in this context, for Bentonite). The model was used in the simulation of selected lab-scale experiments with the open source code OpenGeoSys and was compared to measurements.
In WP5, the newly developed model was used to simulate two experiments, one each at the laboratory and in-situ scales with the open source code OpenGeoSys. The results were not only compared to measurements, when available, but also compared between participating modelling groups and as a blind-prediction exercise. Thus in BEACON progress was made in the following aspects:
- process understanding in bentonite,
- understanding of bentonite-based geotechnical systems in the repository context,
- evaluation of the long-term evolution of the geotechnical barrier,
- evaluation of the predictive capability of the numerical models and
- identification of topics in bentonite research requiring further investigation in a potential successor to the BEACON project.
Figure 2: BEACON group at Imperial College London
Source: Liliana Gramega
The four-year project was funded by the EU in the Horizon2020 framework - „Euratom research and training programme 2014-2018“ under the Grant Agreement No. 745942 to a total sum of 3.8 Million Euro.
In May 2022 the results of this project were presented at the concluding workshop at Imperial College, London.
Links to publications (public-domain): Beacon – Bentonite Mechanical Evolution (beacon-h2020.eu)
Link to project site: Beacon – Bentonite Mechanical Evolution (beacon-h2020.eu)
