The aim of this study is to characterise the mass and volume of wet unsaturated granular media for an equilibrium state obtained after a compaction or kneading process. For two mixing processes for powder and water, under constant operating conditions, the dry density is correlated to water content by a characteristic relation. As observed in the dynamic compaction of soils, this phenomenon exists also for the kneading and static compaction of different raw materials. An analytical expression is suggested for modelling the relation between these two parameters. (c) 2005 Elsevier B.V. All rights reserved.