1 Determining the unsaturated hydraulic conductivity of a compacted sand-bentonite mixture under constant volume and free-swell conditions Y.J. Cui, A.M. Tang, C. Loiseau, P. Delage Université Paris Est, Ecole des ponts, I. Navier Corresponding author Prof. Yu-Jun Cui ENPC/CERMES 6 et 8 avenue Blaise Pascal, Cité Descartes, Champs-sur-Marne, 77455 MARNE-LA-VALLEE CEDEX 2, France. Tel: 33 1 64 15 35 50 Fax: 33 1 64 15 35 62 E-mail: [email protected]