Consolidation properties of bentonite-sand mixtures, as reclamation materials, were investigated in the one-dimensional consolidation test. From the relationships between the void ratio of nonclay fraction and consolidation pressure was found the existence of a threshold void ratio at which the frictional resistance becomes dominant during consolidation. The threshold value is slightly greater than the maximum void ratio of sand used for the mixtures.

A new standard, which utilizes values of clay content, dry density, and threshold void ratio, is proposed to clarify the boundary between sandy and clayey soils.

The salt infiltration into the mixtures causes a rapid settlement but greatly reduces the swelling in unloading stage. As long as the void ratio of nonclay fraction is less than the threshold value, however, the influence of salt disappears.