, 195 5.8.5 Transition from granular to continuous state

, Mock-up imbibition tests and water transfer laws

, Mock-up imbibition tests in the laboratory

. .. Law, 236 6.4.2 Simulation of swelling pressure tests

P. .. Conclusion,

.. .. Overview,

. .. , Contributions of the present work

. .. Perspectives-for-future-work,

, 3.3 Water retention behaviour and water transfer, Contents xii 7.3.2 Macrostructural swelling dependency on the dry density

, Characterisation of the state transition

. .. List-of-references, , p.251

A. , NF P 94-059. Détermination des masses volumiques minimale et maximale des sols non cohérents, 2000.

I. Agnolin and J. N. Roux, Internal states of model isotropic granular packings. I. Assembling process, geometry, and contact networks, Physical Review E -Statistical, Nonlinear, and Soft Matter Physics, vol.76, issue.6, pp.1-27, 2007.
URL : https://hal.archives-ouvertes.fr/hal-00148554

I. Agnolin and J. N. Roux, Internal states of model isotropic granular packings, vol.76, pp.1-22, 2007.
URL : https://hal.archives-ouvertes.fr/hal-00148554

S. S. Agus and T. Schanz, Effect of Shrinking and Swelling on Microstructures and Fabric of a Compacted Bentonite-Sand Mixture, Proceedings of International Conference on Problematic Soils, pp.25-27, 2005.

S. S. Agus, Y. F. Arifin, S. Tripathy, and T. Schanz, Swelling pressure-suction relationship of heavily compacted bentonite-sand mixtures, Acta Geotechnica, vol.8, issue.2, pp.155-165, 2013.

G. D. Aitchison, K. Russam, and B. G. Richards, Engineering concepts of moisture equilibria and moisture changes in soils, p.38, 1965.

M. Al-mukhtar, Y. Qi, J. Alcover, and F. Bergaya, Oedometric and water-retention behaviour of highly compacted unsaturated smectites, Canadian Geotechnical Journal, vol.36, issue.4, pp.675-684, 1999.

E. E. Alonso, A. Gens, and A. Josa, A constitutive model for partially saturated soils, Géotechnique, vol.40, issue.3, pp.405-430, 1990.

E. E. Alonso, C. Hoffmann, and E. Romero, Pellet mixtures in isolation barriers, Journal of Rock Mechanics and Geotechnical Engineering, vol.2, issue.1, pp.12-31, 2010.

,

E. E. Alonso, J. Pereira, J. Vaunat, and S. Olivella, A microstructurally based effective stress for unsaturated soils, Géotechnique, vol.60, issue.12, pp.913-925, 2010.
URL : https://hal.archives-ouvertes.fr/hal-00542292

E. E. Alonso, E. Romero, and C. Hoffmann, Hydromechanical behaviour of compacted granular expansive mixtures: experimental and constitutive study, Géotechnique, vol.61, issue.4, pp.329-344, 2011.

E. E. Alonso, E. Romero, C. Hoffmann, and E. García-escudero, Expansive bentonite-sand mixtures in cyclic controlled-suction drying and wetting, Engineering Geology, vol.81, issue.3, pp.213-226, 2005.

E. E. Alonso, J. Vaunat, and A. Gens, Modelling the mechanical behaviour of expansive clays, Engineering Geology, vol.54, issue.1-2, pp.173-183, 1999.

A. , Evaluation of the feasibility of a geological repository in an argillaceous formation, 2005.

W. Baille, S. Tripathy, and T. Schanz, Swelling pressures and one-dimensional compressibility behaviour of bentonite at large pressures, Applied Clay Science, vol.48, issue.3, pp.324-333, 2010.

R. Baker and S. Frydman, Unsaturated soil mechanics, Critical review of physical foundations. Engineering Geology, vol.106, issue.1-2, pp.26-39, 2009.

A. A. Basma, A. S. Al-homoud, and A. Husein, Laboratory assessment of swelling pressure of expansive soils, Applied Clay Science, vol.9, issue.5, p.32, 1995.

L. S. Bennethum, M. A. Murad, and J. H. Cushman, Modified Darcy's law, Terzaghi's effective stress principle and Fick's law for swelling clay soils, Computers and Geotechnics, vol.20, issue.3-4, pp.245-266, 1997.

X. Bian, Y. Cui, and X. Li, Voids effect on the swelling behaviour of compacted bentonite, 2016.
URL : https://hal.archives-ouvertes.fr/hal-02499281

A. W. Bishop, The principle of effective stress, Teknisk ukeblad, vol.39, pp.859-863, 1959.

J. A. Blatz, Y. J. Cui, and L. Oldecop, Vapour equilibrium and osmotic technique for suction control, Laboratory and Field Testing of Unsaturated Soils, pp.49-61, 2008.

J. A. Blatz, J. Graham, and N. A. Chandler, Influence of suction on the strength and stiffness of compacted sand–bentonite, Canadian Geotechnical Journal, vol.39, issue.5, pp.1005-1015, 2002.

M. D. Bolton, Y. Nakata, and Y. P. Cheng, Micro-and macro-mechanical behaviour of DEM crushable materials, Géotechnique, vol.58, issue.6, pp.471-480, 2008.

L. Börgesson, O. Karnland, and L. E. Johannesson, Modelling of the physical behaviour of clay barriers close to water saturation, Engineering Geology, pp.127-144, 1996.

I. C. Bourg, A. C. Bourg, and G. Sposito, Modeling diffusion and adsorption in compacted bentonite: A critical review, Journal of Contaminant Hydrology, vol.61, issue.1-4, pp.128-134, 2003.

B. Carrier, M. Vandamme, R. J. Pellenq, M. Bornert, E. Ferrage et al., Effect of Water on Elastic and Creep Properties of Self-Standing Clay Films, Langmuir, vol.32, issue.5, pp.1370-1379, 2016.
URL : https://hal.archives-ouvertes.fr/hal-01975527

E. Castellanos, A. Gens, A. Lloret, and E. Romero, Influence of water chemistry on the swelling capacity of a high-density bentonite, Unsaturated Soils, pp.962-972, 2006.

E. Castellanos, M. V. Villar, E. Romero, A. Lloret, and A. Gens, Chemical impact on the hydromechanical behaviour of high-density FEBEX bentonite, Physics and Chemistry of the Earth, vol.33, issue.1, pp.516-526, 2008.

Y. P. Cheng, M. D. Bolton, and Y. Nakata, Crushing and plastic deformation of soils simulated using DEM, Géotechnique, vol.54, issue.2, pp.131-141, 2004.

J. Christoffersen, M. M. Mehrabadi, and S. Nemat-nasser, A micromechanical description of granular material behavior, Journal of applied mechanics, vol.48, issue.2, pp.339-344, 1981.

G. L. Clark, R. E. Grim, and W. F. Bradley, A Study of the Behavior of Montmorillonite upon Wetting, Zeitschrift Für Kristallographie -Crystalline Materials, 97, pp.216-222, 2014.

O. Coussy, J. M. Pereira, and J. Vaunat, Revisiting the thermodynamics of hardening plasticity for unsaturated soils, Computers and Geotechnics, vol.37, issue.1-2, pp.207-215, 2010.
URL : https://hal.archives-ouvertes.fr/hal-00525843

,

O. Coussy, Mechanics of porous continua, vol.1016, 1995.

D. Croney, J. D. Coleman, and W. P. Black, Movement and distribution of water in soil in relation to highway design and performance. Water and Its Conduction in Soils, Highway Res Board, Special Report, issue.40, pp.226-252, 1958.

Y. J. Cui, On the hydro-mechanical behaviour of MX80 bentonite-based materials, Journal of Rock Mechanics and Geotechnical Engineering, vol.9, issue.3, pp.565-574, 2017.
URL : https://hal.archives-ouvertes.fr/hal-01982206

,

Y. J. Cui, A. M. Tang, C. Loiseau, and P. Delage, Determining the unsaturated hydraulic conductivity of a compacted sand-bentonite mixture under constant-volume and free-swell conditions, Physics and Chemistry of the Earth, vol.33, issue.1, pp.462-471, 2008.
URL : https://hal.archives-ouvertes.fr/hal-00343508

Y. J. Cui, M. Yahia-aissa, and P. Delage, A model for the volume change behaviour of heavily compacted swelling clays, Engineering Geology, vol.64, issue.2-3, pp.233-250, 2002.

, , pp.113-115

Y. Cui, C. Loiseau, and P. Delage, Microstructure changes of a confined swelling soil due to suction controlled hydration, Proc 3rd Int Conf on Unsaturated Soils UNSAT, pp.593-598, 2002.

O. Cuisinier and L. Laloui, Fabric evolution during hydromechanical loading of a compacted silt, International Journal for Numerical and Analytical Methods in Geomechanics, vol.28, issue.6, pp.483-499, 2004.
URL : https://hal.archives-ouvertes.fr/hal-01754070

O. Cuisinier and F. Masrouri, Hydromechanical behaviour of a compacted swelling soil over a wide suction range, Engineering Geology, vol.81, issue.3, pp.204-212, 2005.
URL : https://hal.archives-ouvertes.fr/hal-01768451

,

P. Cundall and O. Strack, A discrete numerical model for granular assemblies, Géotechnique, vol.29, issue.1, pp.47-65, 1979.

C. A. Davy, F. Skoczylas, J. D. Barnichon, and P. Lebon, Permeability of macro-cracked argillite under confinement: gas and water testing, Physics and Chemistry of the Earth, pp.667-680, 2007.
URL : https://hal.archives-ouvertes.fr/hal-00155358

F. De-larrard, Concrete mixture proportioning: a scientific approach, 2014.

P. Delage and Y. Cui, L'eau dans les sols non saturés, 2000.

P. Delage and Y. J. Cui, An evaluation of the osmotic method of controlling suction, Geomechanics and Geoengineering, vol.3, issue.1, pp.1-11, 2008.
URL : https://hal.archives-ouvertes.fr/hal-00261634

P. Delage and G. Lefebvre, Study of the structure of a sensitive clay and of its evolution during consolidation, Canadian Geotechnical Journal, vol.21, pp.21-35, 1984.

P. Delage and F. M. Pellerin, Influence de la lyophilisation sur la structure d'une argile sensible du Québec, Clay Minerals, vol.19, pp.151-160, 1984.

P. Delage, M. Audiguier, Y. J. Cui, and M. D. Howat, Microstructure of a compacted silt, Canadian Geotechnical Journal, vol.33, pp.150-158, 1996.

P. Delage, M. D. Howat, and Y. J. Cui, The relationship between suction and swelling properties in a heavily compacted unsaturated clay, Engineering Geology, vol.50, issue.1-2, pp.31-48, 1998.

P. Delage, D. Marcial, X. Ruiz, and Y. J. Cui, Ageing effects in a compacted bentonite: a microstructure approach, Géotechnique, vol.56, issue.5, pp.291-304, 2006.

,

P. Delage, E. Romero, and A. Tarantino, Recent developments in the techniques of controlling and measuring suction in unsaturated soils, Unsaturated Soils: Advances in Geo-Engineering -Proceedings of the 1st European Conference on Unsaturated Soils, E-UNSAT 2008, pp.33-52, 2008.
URL : https://hal.archives-ouvertes.fr/hal-00331841

D. Vecchia, G. Dieudonné, A. C. Jommi, C. Charlier, and R. , Accounting for evolving pore size distribution in water retention models for compacted clays, International Journal for Numerical and Analytical Methods in Geomechanics, vol.39, pp.702-723, 2015.

,

A. C. Dieudonne, G. Della-vecchia, and R. Charlier, Water retention model for compacted bentonites, Canadian Geotechnical Journal, vol.54, issue.7, pp.915-925, 2017.

A. C. Dieudonné, Hydromechanical behaviour of compacted bentonite: from micro-scale analysis to macro-scale modelling, 2016.

D. A. Dixon, Swelling and hydraulic properties of bentonites from Japan, Canada and the USA, Proceedings of the Second International Congress on Environmental Geotechnics (IS-Osaka), vol.1, pp.43-48, 1996.

D. A. Dixon, J. Graham, and M. N. Gray, Hydraulic conductivity of clays in confined tests under low hydraulic gradients, Canadian Geotechnical Journal, vol.36, issue.5, pp.815-825, 1999.

,

J. M. Fleureau, S. Kheirbek-saoud, R. Soemitro, and S. Taibi, Behavior of clayey soils on drying-wetting paths, Canadian Geotechnical Journal, vol.30, issue.2, pp.287-296, 1993.

,

D. G. Fredlund and N. R. Morgenstern, Stress state variables for unsaturated soils, Journal of Geotechnical and Geoenvironmental Engineering, vol.103, 1977.

M. García-gutiérrez, M. Mingarro, T. Missana, P. L. Martín, L. A. Sedano et al., Diffusion experiments with compacted powder/pellets clay mixtures, Applied Clay Science, vol.26, issue.1-4, pp.57-64, 2004.

J. L. Garcia-sineriz, M. V. Villar, M. Rey, and B. Palacios, Engineered barrier of bentonite pellets and compacted blocks: State after reaching saturation, Engineering Geology, vol.192, pp.33-45, 2015.

C. Gatabin, J. Talandier, F. Collin, R. Charlier, and A. C. Dieudonné, Competing effects of volume change and water uptake on the water retention, 2016.

, bentonite/sand mixture, Applied Clay Science, pp.57-62

,

A. Gens, Soil-environment interactions in geotechnical engineering, Géotechnique, vol.60, issue.1, pp.3-74, 2010.

A. Gens and E. E. Alonso, A framework for the behaviour of unsaturated expansive clays, Canadian Geotechnical Journal, vol.29, pp.1013-1032, 1992.

A. Gens, B. Valleján, M. Sánchez, C. Imbert, M. V. Villar et al., Hydromechanical behaviour of a heterogeneous compacted soil: experimental observations and modelling, 2011.

. Géotechnique, , pp.367-386

A. Gens, B. Valleján, M. T. Zandarín, and M. Sánchez, Homogenization in clay barriers and seals: Two case studies, Journal of Rock Mechanics and Geotechnical Engineering, vol.5, issue.3, pp.191-199, 2013.

M. Gouy, Sur la constitution de la charge électrique à la surface d'un électrolyte, Journal de Physique Théorique et Appliquée, vol.9, issue.1, pp.457-468, 1910.

,

S. B. Hendricks, R. A. Nelson, and L. T. Alexander, Hydration Mechanism of the Clay Mineral Montmorillonite Saturated with Various Cations, Journal of the American Chemical Society, vol.62, issue.6, pp.1457-1464, 1940.

C. Hoffmann, E. E. Alonso, and E. Romero, Hydro-mechanical behaviour of bentonite pellet mixtures, Physics and Chemistry of the Earth, vol.32, issue.8-14, pp.832-849, 2007.

,

C. Imbert and M. V. Villar, Hydro-mechanical response of a bentonite pellets/powder mixture upon infiltration, Applied Clay Science, vol.32, issue.3-4, pp.197-209, 2006.

,

C. Imbert, P. Billaud, G. Touzé, and K. D. Dang, Acquisition des paramètres de comportement hydraulique et hydromécanique de base de l'argile MX80 à l'état saturé, 2004.

A. C. Jacinto, M. V. Villar, and A. Ledesma, Influence of water density on the water-retention curve of expansive clays, Géotechnique, vol.62, issue.8, pp.657-667, 2012.

K. L. Johnson, Contact Mechanics, 1985.

C. Jommi, Remarks on the constitutive modelling of unsaturated soils. Experimental Evidence and Theoretical Approaches in Unsaturated Soils, pp.139-153, 1968.

O. Karnland, U. Nilsson, H. Weber, and P. Wersin, Sealing ability of Wyoming bentonite pellets foreseen as buffer material -Laboratory results, Physics and Chemistry of the Earth, vol.33, 2008.

, , pp.472-475

O. Karnland, S. Olsson, and U. Nilsson, Mineralogy and sealing properties of various bentonites and smectite-rich clay materials, SKB Technical Report, 2006.

S. Kaufhold, W. Baille, T. Schanz, and R. Dohrmann, About differences of swelling pressuredry density relations of compacted bentonites, Applied Clay Science, vol.107, pp.52-61, 2015.

L. M. Keller, A. Seiphoori, P. Gasser, F. Lucas, L. Holzer et al., The pore structure of compacted and partly saturated MX-80 bentonite at different dry densities, Clays and Clay Minerals, vol.62, issue.3, pp.174-187, 2014.

N. Khalili, F. Geiser, and G. Blight, Effective Stress in Unsaturated Soils: Review with New Evidence, International Journal of Geomechanics, vol.4, issue.2, pp.115-126, 2004.

H. Komine, Simplified evaluation on hydraulic conductivities of sand-bentonite mixture backfill, Applied Clay Science, vol.26, issue.1-4, pp.13-19, 2004.

,

H. Komine, Theoretical equations on hydraulic conductivities of bentonite-based buffer and backfill for underground disposal of radioactive wastes, Journal of Geotechnical and Geoenvironmental Engineering, vol.134, issue.4, pp.4-497, 2008.

H. Komine, Predicting hydraulic conductivity of sand-bentonite mixture backfill before and after swelling deformation for underground disposal of radioactive wastes, Engineering Geology, vol.114, issue.3-4, pp.123-134, 2010.

H. Komine and N. Ogata, New equations for swelling characteristics of bentonite-based buffer materials, Canadian Geotechnical Journal, vol.40, issue.2, pp.460-475, 2003.

K. P. Kröhn, Modelling the re-saturation of bentonite in final repositories in crystalline rock, 2004.

K. P. Kröhn, New evidence for the dominance of vapour diffusion during the re-saturation of compacted bentonite, Engineering Geology, vol.82, issue.2, pp.127-132, 2005.

,

L. Laloui and M. Nuth, On the use of the generalised effective stress in the constitutive modelling of unsaturated soils, Computers and Geotechnics, vol.36, issue.1-2, pp.20-23, 2009.

,

I. Langmuir, The constitution and fundamental properties of solids and liquids, Journal of the American Chemical Society, vol.39, pp.1848-1906, 1917.

I. Langmuir, The role of attractive and repulsive forces in the formation of tactoids, thixotropic gels, protein crystals and coacervates, The Journal of Chemical Physics, vol.6, issue.12, pp.873-896, 1938.

G. P. Lawrence, Stability of soil pores during mercury intrusion porosimetry, Journal of Soil Science, vol.29, issue.3, pp.299-304, 1978.

H. H. Liu, L. Li, and J. Birkholzer, Unsaturated properties for non-Darcian water flow in clay, Journal of Hydrology, pp.173-178, 2012.

H. Liu, D. Zou, and J. Liu, Particle Shape Effect on Macro-and Micro Behaviours of Monodisperse Ellipsoids, International Journal for Numerical and Analytical Methods in Geomechanics, vol.32, pp.189-213, 2007.

A. Lloret and M. V. Villar, Advances on the knowledge of the thermo-hydro-mechanical behaviour of heavily compacted "FEBEX" bentonite, Physics and Chemistry of the Earth, vol.32, issue.8-14, pp.701-715, 2007.

A. Lloret, M. V. Villar, M. Sanchez, A. Gens, X. Pintado et al., Mechanical behaviour of heavily compacted bentonite under high suction changes, Geotechnique, vol.53, issue.1, pp.27-40, 2003.

P. F. Low, Nature and properties of water in montmorillonite-water systems, Soil Science Society of America Journal, vol.43, issue.4, pp.651-658, 1979.

F. T. Madsen and M. Müller-vonmoos, The swelling behaviour of clays, Applied Clay Science, vol.4, issue.2, pp.90005-90012, 1989.

D. Marcial, Comportement hydromécanique et microstructural des matériaux de barrière ouvragée, Doctoral dissertation, École nationale des ponts et chaussées (France), 2003.

D. Masin and N. Khalili, Swelling phenomena and effective stress in compacted expansive clays, Canadian Geotechnical Journal, vol.53, pp.134-147, 2016.

L. Massat, O. Cuisinier, I. Bihannic, F. Claret, M. Pelletier et al., Swelling pressure development and inter-aggregate porosity evolution upon hydration of a compacted swelling clay, Applied Clay Science, pp.197-210, 2016.
URL : https://hal.archives-ouvertes.fr/hal-01409015

,

J. C. Mayor, J. L. García-siñeriz, E. Alonso, H. J. Alheid, and P. Blumbling, Engineered barrier emplacement experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories, 2005.

A. Meunier, , 2005.

N. Mokni, J. D. Barnichon, P. Dick, and T. S. Nguyen, Effect of technological macro voids on the performance of compacted bentonite/sand seals for deep geological repositories, International Journal of Rock Mechanics and Mining Sciences, vol.88, pp.87-97, 2016.
URL : https://hal.archives-ouvertes.fr/hal-02559827

,

N. Mokni, A. Molinero-guerra, Y. Cui, P. Delage, P. Aimedieu et al., Modelling the long-term hydro-mechanical behaviour of a bentonite pellet/powder mixture with consideration of initial structural heterogeneities, pp.1-61, 2019.

,

A. Molinero-guerra, N. Mokni, P. Delage, Y. J. Cui, A. M. Tang et al., In-depth characterisation of a mixture composed of powder/pellets MX80 bentonite, Applied Clay Science, vol.135, pp.538-546, 2017.
URL : https://hal.archives-ouvertes.fr/hal-01515960

A. Molinero-guerra, P. Aimedieu, M. Bornert, Y. J. Cui, A. M. Tang et al., Analysis of the structural changes of a pellet/powder bentonite mixture upon wetting by X-ray computed microtomography, Applied Clay Science, vol.165, pp.164-169, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01982134

A. Molinero-guerra, Y. J. Cui, N. Mokni, P. Delage, M. Bornert et al., Investigation of the hydro-mechanical behaviour of a pellet/powder MX80 bentonite mixture using an infiltration column, Engineering Geology, pp.18-25, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01982129

A. Molinero-guerra, P. Delage, Y. Cui, N. Mokni, A. M. Tang et al., Water retention properties and microstructure changes of a bentonite pellet upon wetting/drying; application to radioactive waste disposal, pp.1-41, 2019.
URL : https://hal.archives-ouvertes.fr/hal-02879298

A. Molinero-guerra, Y. J. Cui, Y. He, P. Delage, N. Mokni et al., Characterization of water retention, compressibility and swelling properties of a pellet/powder bentonite mixture, Engineering Geology, pp.14-21, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01982177

G. Montes-hernandez, J. Duplay, L. Martinez, and C. Mendoza, Swelling-shrinkage kinetics of MX80 bentonite, Applied Clay Science, vol.22, issue.6, pp.120-120, 2003.

K. Norrish, The swelling of montmorillonite, Discussions of the Faraday Society, vol.18, pp.120-134, 1954.

H. Nowamooz and F. Masrouri, Hydromechanical behaviour of an expansive bentonite/silt mixture in cyclic suction-controlled drying and wetting tests, Engineering Geology, vol.101, issue.3-4, pp.154-164, 2008.

H. Nowamooz and F. Masrouri, Density-dependent hydromechanical behaviour of a compacted expansive soil, Engineering Geology, vol.106, issue.3-4, pp.105-115, 2009.
URL : https://hal.archives-ouvertes.fr/hal-00695842

,

M. Nuth and L. Laloui, Advances in modelling hysteretic water retention curve in deformable soils, Computers and Geotechnics, vol.35, issue.6, pp.835-844, 2008.

,

F. E. O'brien, The Control of Humidity by Saturated Salt Solutions, Journal of Scientific Instruments, vol.25, issue.3, pp.73-76, 1948.

S. Olivella and A. Gens, Vapour transport in low permeability unsaturated soils with capillary effects, Transport in Porous Media, vol.40, pp.219-241, 2000.

B. Palacios, M. Rey, J. L. Garcia-siñeriz, M. V. Villar, J. C. Mayor et al., Engineered Barrier Emplacement Experiment in Opalinus Clay "EB" Experiment. As-built of dismantling operation. Long-term Performance of Engineered Barrier Systems PEBS. European Commission, 7th Euratom Framework Program for Nuclear Research and Training Activities, 2007.

J. M. Pereira, H. Wong, P. Dubujet, and P. Dangla, Adaptation of existing behaviour models to unsaturated states: Application to CJS model, International Journal for Numerical and Analytical Methods in Geomechanics, vol.29, issue.11, pp.1127-1155, 2005.
URL : https://hal.archives-ouvertes.fr/hal-00140210

J. R. Philip and D. A. De-vries, Moisture movements in porous materials under temperature gradients, Transactions, vol.38, issue.2, pp.222-232, 1957.

R. Pusch, Highly Compacted Sodium Bentonite for Isolating Rock-Deposited Radioactive Waste Products, Nuclear Technology, vol.45, issue.2, pp.153-157, 1979.

R. Pusch and R. N. Yong, Microstructure of smectite clays and engineering performance, 2006.

R. Push, The Buffer and Backfill Handbook part 2: Materials and techniques, Sweden: Swedish Nuclear Fuel and Waste Management Co, 2001.

F. Radjai and F. Dubois, Discrete-element modeling of granular materials, 2011.
URL : https://hal.archives-ouvertes.fr/hal-00691805

L. A. Richards, A pressure-membrane extraction apparatus for soil solution, Soil Science, vol.51, issue.5, pp.377-386, 1941.

E. Romero, A microstructural insight into compacted clayey soils and their hydraulic properties, Engineering Geology, vol.165, pp.3-19, 2013.

E. Romero and P. H. Simms, Microstructure investigation in unsaturated soils: A review with special attention to contribution of mercury intrusion porosimetry and environmental scanning electron microscopy, Geotechnical and Geological Engineering, vol.26, pp.705-727, 2008.

E. Romero, G. Della-vecchia, and C. Jommi, An insight into the water retention properties of compacted clayey soils, Géotechnique, vol.61, issue.4, pp.313-328, 2011.

,

E. Romero, A. Gens, and A. Lloret, Water permeability, water retention and microstrucutre of unsaturated compacted boom clay, Engineering Geology, vol.54, pp.117-127, 1999.

, , pp.67-75

E. Romero, . Gens, and . Lloret, Suction effects on a compacted clay under non-isothermal conditions, Géotechnique, vol.53, issue.1, pp.65-81, 2003.

E. Romero, M. V. Villar, and A. Lloret, Thermo-hydro-mechanical behaviour of two heavily overconsolidated clays, Engineering Geology, vol.81, issue.3, pp.255-268, 2005.

,

G. Roquier, Etude théorique des effets de paroi et de desserrement dans les mélanges granulaires, Ecole Nationale Des Ponts et Chaussées, p.614, 2015.

J. Roux, Geometric origin of mechanical properties of granular materials, Physical Review E -Statistical, Nonlinear, and Soft Matter Physics, issue.6, pp.1-35, 2000.
URL : https://hal.archives-ouvertes.fr/hal-00126196

J. Roux and F. Chevoir, Généralités sur la simulation numérique discrète des matériaux granulaires, vol.254, pp.109-138, 2005.

J. Roux, F. Chevoir, and F. Toussaint, Etats de compacité maximale pour les mélanges binaires de grains sphériques : étude par simulation numérique, Bulletin Des Laboratoires Des Ponts et Chaussées, pp.141-152, 2007.

S. Saba, J. D. Barnichon, Y. J. Cui, A. M. Tang, and P. Delage, Microstructure and anisotropic swelling behaviour of compacted bentonite/sand mixture, Journal of Rock Mechanics and Geotechnical Engineering, vol.6, issue.2, pp.126-132, 2014.
URL : https://hal.archives-ouvertes.fr/hal-02611888

S. Saba, Y. Cui, A. M. Tang, and J. Barnichon, Investigation of the swelling behaviour of compacted bentonite-sand mixtures by mock-up tests, Canadian Geotechnical Journal, vol.51, pp.1399-1412, 2014.

N. Saiyouri, P. Y. Hicher, and D. Tessier, Microstructural approach and transfer water modelling in highly compacted unsaturated swelling clays, Mechanics of Cohesive-Frictional Materials, vol.5, pp.41-60, 2000.
URL : https://hal.archives-ouvertes.fr/hal-01007048

N. Saiyouri, D. Tessier, and P. Y. Hicher, Experimental study of swelling in unsaturated compacted clays, Clay Minerals, vol.39, issue.4, pp.469-479, 2004.
URL : https://hal.archives-ouvertes.fr/hal-01006853

M. Sánchez, A. Gens, L. Do-nascimento-guimarães, and S. Olivella, A double structure generalized plasticity model for expansive materials, International Journal for Numerical and Analytical Methods in Geomechanics, vol.29, issue.8, pp.751-787, 2005.

M. Sánchez, A. Gens, M. V. Villar, and S. Olivella, Fully Coupled Thermo-Hydro-Mechanical Double-Porosity Formulation for Unsaturated Soils, International Journal of Geomechanics, 2016.

A. Schneider, Neue dagramme zur bestimmung der relativen luftfeuchtigkeit uber gesattigten wasserigen salzslosungen und wasserigen schwefelsaurelosingen bei verschiedenen temperaturen, Holz als Rohund Werkstoff, vol.18, pp.269-272, 1960.

R. K. Schofield, The pF of water in soil, Trans. of the Third International Congress on Soil Science, vol.2, pp.37-48, 1935.

A. Seiphoori, A. Ferrari, and L. Laloui, Water retention behaviour and microstructural evolution of MX-80 bentonite during wetting and drying cycles, Géotechnique, vol.64, issue.9, pp.721-734, 2014.

P. Sellin and O. X. Leupin, The use of clay as an engineered barrier in radioactive-waste management -A review, Clays and Clay Minerals, issue.6, pp.477-498, 2014.

D. Sheng, A. Gens, D. G. Fredlund, and S. W. Sloan, Unsaturated soils: From constitutive modelling to numerical algorithms, Computers and Geotechnics, vol.35, issue.6, pp.810-824, 2008.

D. Sheng, S. W. Sloan, and A. Gens, A constitutive model for unsaturated soils: Thermomechanical and computational aspects, Computational Mechanics, vol.33, issue.6, pp.453-465, 2004.

G. Sposito and R. Prost, Structure of Water Adsorbed on Smectites. Chemical Reviews, vol.82, issue.6, pp.553-573, 1982.

D. Sun, L. Zhang, J. Li, and B. Zhang, Evaluation and prediction of the swelling pressures of GMZ bentonites saturated with saline solution, Applied Clay Science, pp.207-216, 2015.

H. Sun, D. Ma?ín, J. Najser, V. Nedela, and E. Navrátilová, Bentonite microstructure and saturation evolution in wetting-drying cycles evaluated using ESEM, MIP and WRC measurements, Geotechnique, vol.69, issue.8, pp.713-726, 2019.

T. Sweijen, B. Chareyre, S. M. Hassanizadeh, and N. K. Karadimitriou, Grain-scale modelling of swelling granular materials; application to super absorbent polymers, Powder Technology, vol.318, pp.411-422, 2017.
URL : https://hal.archives-ouvertes.fr/hal-01995021

A. Tang and Y. Cui, Controlling suction by the vapour equilibrium technique at different temperatures and its application in determining the water retention properties of MX80 clay, Canadian Geotechnical Journal, vol.42, issue.1, pp.287-296, 2005.

A. Tang and Y. Cui, Modelling the thermomechanical volume change behaviour of compacted expansive clays, Géotechnique, vol.59, issue.3, pp.185-195, 2009.
URL : https://hal.archives-ouvertes.fr/hal-00377782

,

A. M. Tang, Y. J. Cui, and T. T. Le, A study on the thermal conductivity of compacted bentonites, Applied Clay Science, vol.41, pp.181-189, 2008.
URL : https://hal.archives-ouvertes.fr/hal-00337024

A. Tarantino, A water retention model for deformable soils, Geotechnique, vol.59, issue.9, pp.751-762, 2009.

A. Tarantino, D. Gallipoli, C. E. Augarde, V. De-gennaro, R. Gomez et al., Benchmark of experimental techniques for measuring and controlling suction, Geotechnique, vol.61, issue.4, pp.303-312, 2011.
URL : https://hal.archives-ouvertes.fr/hal-00669323

K. V. Terzaghi, The shearing resistance of saturated soils and the angle between the planes of shear, First international conference on soil Mechanics, vol.1, pp.54-59, 1936.

D. Tessier, Etude expérimentale de l'organisation des matériaux argileux. Hydratation, gonflement et structuration au cours de la dessiccation et de la réhumectation, 1984.

D. Tessier, A. Lajudie, and J. C. Petit, Relation between the macroscopic behavior of clays and their microstructural properties, Applied Geochemistry, vol.7, pp.151-161, 1992.
URL : https://hal.archives-ouvertes.fr/hal-02710118

, , pp.80071-80072

M. Tuller, O. Dani, and L. M. Dudley, Adsorption and capillary condensation in porous media: Liquid retention and interfacial configurations in angular pores, Water Resources Research, vol.35, issue.7, pp.1949-1964, 1999.

T. Ueda, T. Matsushima, and Y. Yamada, Effect of particle size ratio and volume fraction on shear strength of binary granular mixture, Granular Matter, vol.13, issue.6, pp.731-742, 2011.

L. E. Vallejo, Interpretation of the limits in shear strength in binary granular mixtures, Canadian Geotechnical Journal, vol.38, issue.5, pp.1097-1104, 2001.

M. Van-geet, G. Volckaert, and S. Roels, The use of microfocus X-ray computed tomography in characterising the hydration of a clay pellet/powder mixture, Applied Clay Science, vol.29, issue.2, pp.73-87, 2005.

M. T. Van-genuchten, A Closed-form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils1, Soil Science Society of America Journal, 1980.

W. L. Vargas and J. J. Mccarthy, Thermal expansion effects and heat conduction in granular materials, Nonlinear, and Soft Matter Physics, vol.76, issue.4, pp.1-8, 2007.

J. Vaunat and F. Casini, A procedure for the direct determination of Bishop's ? parameter from changes in pore size distribution, Géotechnique, vol.67, issue.7, pp.631-636, 2017.

,

J. Vaunat and A. Gens, Analysis of the hydration of a bentonite seal in a deep radioactive waste repository, Engineering Geology, vol.81, issue.3, pp.317-328, 2005.

M. V. Villar, Investigation of the behaviour of bentonite by means of suction-controlled oedometer tests, Engineering Geology, vol.54, issue.1-2, pp.62-71, 1999.

M. V. Villar, Caracterizacion termo-hidro-mecánica de una bentonita de Cabo de Gata, vol.396, 2000.

M. V. Villar, MX80 bentonite. Thermo-Hydro-Mechanical Characterisation Performed at CIEMAT in the Context of the Prototype Project, Informes Técnicos Ciemat, p.1053, 2005.

M. V. Villar, Water retention of two natural compacted bentonites, Clays and Clay Minerals, vol.55, issue.3, pp.311-322, 2007.

M. V. Villar and A. Lloret, Influence of dry density and water content on the swelling of a compacted bentonite, Applied Clay Science, vol.39, issue.1-2, pp.38-49, 2008.

,

M. V. Villar, P. L. Martín, and J. M. Barcala, Modification of physical, mechanical and hydraulic properties of bentonite by thermo-hydraulic gradients, Engineering Geology, vol.81, issue.3, pp.284-297, 2005.

M. V. Villar, J. L. García-siñeriz, I. Bárcena, and A. Lloret, State of the bentonite barrier after five years operation of an in situ test simulating a high level radioactive waste repository, Engineering Geology, vol.80, issue.3-4, pp.175-198, 2005.

M. V. Villar, Thermo-hydro-mechanical characterisation of a bentonite from Cabo de Gata. A Study Applied to the Use of Bentonite as Sealing Material in High Level Radioactive Waste Repositories, 2008.

G. Volckaert, F. Bernier, E. Alonso, A. Gens, J. Samper et al., Thermal-hydraulic-mechanical and geochemical behaviour of the clay barrier in radioactive waste repositories (model development and validation). Nuclear Science and Technology, vol.722, 1996.

Q. Wang, A. M. Tang, Y. J. Cui, P. Delage, and B. Gatmiri, Experimental study on the swelling behaviour of bentonite/claystone mixture, Engineering Geology, vol.124, issue.1, pp.59-66, 2012.
URL : https://hal.archives-ouvertes.fr/hal-00655761

Q. Wang, A. M. Tang, Y. J. Cui, P. Delage, J. D. Barnichon et al., The effects of technological voids on the hydro-mechanical behaviour of compacted bentonite-sand mixture, Soils and Foundations, vol.53, issue.2, pp.232-245, 2013.
URL : https://hal.archives-ouvertes.fr/hal-00829480

Q. Wang, Y. J. Cui, A. M. Tang, J. D. Barnichon, S. Saba et al., Hydraulic conductivity and microstructure changes of compacted bentonite/sand mixture during hydration, Engineering Geology, vol.164, pp.67-76, 2013.
URL : https://hal.archives-ouvertes.fr/hal-00926873

Q. Wang, A. M. Tang, Y. J. Cui, J. D. Barnichon, and W. M. Ye, A comparative study on the hydro-mechanical behavior of compacted bentonite/sand plug based on laboratory and field infiltration tests, Engineering Geology, vol.162, pp.79-87, 2013.

Q. Wang, A. Minh, Y. Cui, J. Barnichon, and W. Ye, Investigation of the hydro-mechanical behaviour of compacted bentonite / sand mixture based on the BExM model, Computers and Geotechnics, vol.54, pp.46-52, 2013.
URL : https://hal.archives-ouvertes.fr/hal-00926870

L. Warr and J. Berger, Hydration of bentonite in natural waters: Application of "confined volume" wet-cell X-ray diffractometry, Physics and Chemistry of the Earth, vol.32, issue.1-7, pp.247-258, 2007.
URL : https://hal.archives-ouvertes.fr/hal-00137600

A. E. Westman and H. R. Hugill, the Packing of Particles, Journal of the American Ceramic Society, vol.13, issue.10, pp.767-779, 1930.

J. Wiacek, M. Molenda, J. Horabik, and J. Y. Ooi, Influence of grain shape and intergranular friction on material behavior in uniaxial compression: Experimental and DEM modeling, Powder Technology, vol.217, pp.435-442, 2012.

B. Wiebe, J. Graham, G. X. Tang, and D. Dixon, Influence of pressure, saturation, and temperature on the behaviour of unsaturated sand-bentonite, Canadian Geotechnical Journal, vol.35, pp.194-205, 1998.

K. Wieczorek, I. Gaus, J. C. Mayor, K. Schuster, J. L. García-siñeriz et al., In-situ experiments on bentonite-based buffer and sealing materials at the Mont Terri rock laboratory (Switzerland), Swiss Journal of Geosciences, vol.110, issue.1, pp.253-268, 2017.

J. Williams and C. F. Shaykewich, An evaluation of polyethylene glycol (P.E.G.) 6000 and P.E.G. 20,000 in the osmotic control of soil water matric potential, Canadian Journal of Soil Science, vol.49, pp.397-401, 1969.

L. Xu, W. M. Ye, B. Chen, Y. G. Chen, and Y. J. Cui, Experimental investigations on thermohydro-mechanical properties of compacted GMZ01 bentonite-sand mixture using as buffer materials, Engineering Geology, vol.213, pp.46-54, 2016.

W. M. Ye, Y. J. Cui, L. X. Qian, and B. Chen, An experimental study of the water transfer through confined compacted GMZ bentonite, Engineering Geology, vol.108, issue.3-4, pp.169-176, 2009.
URL : https://hal.archives-ouvertes.fr/hal-00418913

S. Yerazunis, S. W. Cornell, and B. Wintner, Dense random packing of binary mixtures of spheres, Nature, issue.4999, p.835, 1965.

Z. G. Yigzaw, O. Cuisinier, L. Massat, and F. Masrouri, Role of different suction components on swelling behavior of compacted bentonites, Applied Clay Science, vol.120, pp.81-90, 2016.
URL : https://hal.archives-ouvertes.fr/hal-01409037

S. Zhao, T. M. Evans, X. Zhou, and S. Zhou, Discrete element method investigation on thermally-induced shakedown of granular materials, Granular Matter, vol.19, issue.1, pp.1-11, 2017.

M. Zhou, S. Caré, D. Courtier-murias, P. Faure, S. Rodts et al., Magnetic resonance imaging evidences of the impact of water sorption on hardwood capillary imbibition dynamics, Wood Science and Technology, vol.52, issue.4, pp.929-955, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01803000