Temperature Influence on the Mechanical Behaviour of a Compacted Bentonite

Abstract The design of high level radioactive waste (HLW) repositories in deep geological media –in which bentonite is proposed as sealing material– leads to the necessity of deepening the study of the behaviour of clays when subjected to hydraulic and thermal changes. The paper presents the results of an experimental study on the effects of temperature on the volumetric behaviour of a compacted bentonite used in FEBEX, which is a project for the study of the near field for a HLW repository according to the Spanish concept. The experimental programme includes swelling under load tests, swelling pressure tests and oedometric compression tests with and without control of suction. The results indicate that temperature reduces the swelling capacity and the swelling pressure and increases the volumetric strains induced by vertical loads due to a reduction of the yielding stress

[1]  F. Huertas,et al.  Project FEBEX-Full-scale Engineered Barriers Experiment for a deep geological repository for high-level radioactive waste in crystalline host rock , 2002 .

[2]  Antonio Gens,et al.  Modelling the mechanical behaviour of expansive clays , 1999 .

[3]  Tomasz Hueckel,et al.  Stress and pore pressure in saturated clay subjected to heat from radioactive waste: a numerical simulation , 1992 .

[4]  James Graham,et al.  Influence of pressure, saturation, and temperature on the behaviour of unsaturated sand-bentonite , 1998 .

[5]  J. Graham,et al.  Effects of temperature on strength and compressibility of sand-bentonite buffer , 1996 .

[6]  Antonio Gens,et al.  A framework for the behaviour of unsaturated expansive clays , 1992 .

[7]  T. Hueckel,et al.  Thermal volume changes of the mineral–water system in low-porosity clay soils , 1988 .

[8]  Y. Cui,et al.  Temperature effects on the volume change behaviour of Boom clay , 2002 .

[9]  I. Towhata,et al.  Volume Change of Clays Induced by Heating as Observed in Consolidation Tests , 1993 .

[10]  J. Graham,et al.  Stress-strain behaviour of reconstituted illitic clay at different temperatures☆ , 1997 .

[11]  Antonio Gens,et al.  Suction effects on a compacted clay under non-isothermal conditions , 2003 .

[12]  Tomasz Hueckel,et al.  Thermoplasticity of Saturated Soils and Shales: Constitutive Equations , 1990 .

[13]  Enrique Romero,et al.  Thermo-hydro-mechanical behaviour of two heavily overconsolidated clays , 2005 .

[14]  S. Miliziano,et al.  A laboratory study on the thermomechanical behaviour of clayey soils , 2000 .