On the behaviour of compacted bentonite under thermal gradients

This paper presents an experimental and modelling study of bentonite behaviour under thermal gradients. The variables measured have been the temperature during the heating process, the final water content and the change of diameter after heating. The change of diameter and the water content after some months have been measured as well. The test has been simulated with CODE_BRIGHT, a numerical code which has the capability to solve the non isothermal multiphase transport in deformable porous media. The results of the study show that the thermo-hydraulic behaviour after the heating process can be properly simulated. The thermo-hydro-mechanical and the long term behaviour could not, however, be reproduced with the same precision.

► Some bentonite samples of 38 mm diameter × 78 mm height are tested under thermal gradients.
► Temperature is measured continuously and the water content and shape at the end.
► The test is modelled with a finite element code.
► The thermo-hydraulic processes can be modelled properly.
► The mechanical processes and the long term behaviour cannot be reproduced with the same precision.