ABSTRACT
The swelling deformation of compacted Na-bentonite using NaCl solution was investigated. A higher concentration resulted in a lower swelling rate. Upon unloading the void ratio increased along the normal consolidation line, however the unloading curves for deionized water (DW) and NaCl solution differed after a threshold void ratio. The unloading curve in DW gradually increased its slope, whereas that in NaCl seemed to reach upper value. It is indicated that the osmotic effect basically dominates the swelling deformation in lower confining stress and the crystalline swelling of montmorillonite controls the limits of volumetric change in saline solution.
