Thermo-mechanical behaviour of a compacted swelling clay

Anh Minh A.M. Tang (1) , Yu-Jun Cui (1) , Nathalie Barnel (2)

1 CERMES - Centre d'enseignement et de recherche en mécanique des sols
2 EDF - EDF

Compacted unsaturated swelling clay is often considered as a possible buffer material for deep nuclear waste disposal. An isotropic cell permitting simultaneous control of suction, temperature and pressure was used to study the thermo-mechanical behaviour of this clay. Tests were performed at total suctions ranging from 9 to 110 MPa, temperature from 25 to 80 °C, isotropic pressure from 0.1 to 60 MPa. It was observed that heating at constant suction and pressure induces either swelling or contraction. The results from compression tests at constant suction and temperature evidenced that at lower suction, the yield pressure was lower, the elastic compressibility parameter and the plastic compressibility parameter were higher. On the other hand, at a similar suction, the yield pressure was slightly influenced by the temperature; and the compressibility parameters were insensitive to temperature changes. The thermal hardening phenomenon was equally evidenced by following a thermo-mechanical path of loading-heating-cooling-reloading.

Mots clés: temperature effects; Radioactive waste disposal; expansive soils; laboratory tests; compressibility; suction; temperature effects.

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Anh Minh A.M. Tang, Yu-Jun Cui, Nathalie Barnel. Thermo-mechanical behaviour of a compacted swelling clay. Geotechnique, 2008, 58 (1), pp.45-54. ⟨10.1680/geot.2008.58.1.45⟩. ⟨hal-00250248⟩