Poromechanical behaviour of hardened cement paste under isotropic loading

Siavash Ghabezloo (1) , Jean Sulem (1) , Sylvine Guédon (2) , Francçois Martineau (2) , Jérémie Saint-Marc (3)

1 CERMES - Centre d'enseignement et de recherche en mécanique des sols
2 LCPC - Laboratoire Central des Ponts et Chaussées
3 CSTJF - Centre scientifique et Technique Jean Feger

The poromechanical behaviour of hardened cement paste under isotropic loading is studied on the basis of an experimental testing program of drained, undrained and unjacketed compression tests. The macroscopic behaviour of the material is described in the framework of the mechanics of porous media. The poroelastic parameters of the material are determined and the effect of stress and pore pressure on them is evaluated. Appropriate effective stress laws which control the evolution of total volume, pore volume, solid volume, porosity and drained bulk modulus are discussed. A phenomenon of degradation of elastic properties is observed in the test results. The microscopic observations showed that this degradation is caused by the microcracking of the material under isotropic loading. The good compatibility and the consistency of the obtained poromechanical parameters demonstrate that the behaviour of the hardened cement paste can be indeed described within the framework of the theory of porous media.

Mots clés: hardened cement paste; poromechanics; effective stress; degradation; triaxial test; bulk modulus; oilwell cement; porosity

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

Siavash Ghabezloo, Jean Sulem, Sylvine Guédon, Francçois Martineau, Jérémie Saint-Marc. Poromechanical behaviour of hardened cement paste under isotropic loading. Cement and Concrete Research, 2008, 38, pp.1424-1437. ⟨10.1016/j.cemconres.2008.06.007⟩. ⟨hal-00315563⟩