RHEOLOGICAL INTERPRETATION OF DEPOSITS OF YIELD STRESS FLUIDS

Various industrial or natural slurries are coarse, concentrated suspen sions with a yield stress. Relevant practical methods are needed to de termine the behaviour of such fluids. Here we provide a simple, theore tical approach to describe form of deposits remaining after free surfa ce flow stoppage as a function of fluid characteristics. Thixotropy, i nertial effects and sedimentation are neglected. It is demonstrated th at the flow depth, as a function of the distance from the edge, can be predicted in any direction. Further analysis shows that there is a cl ear difference in the form of deposit edge between materials in which there is a grain-to-grain network of interaction and materials in whic h there is a network of colloidal interaction. These results provide a first order, practical, rheological and structural interpretation of current deposits of pastes, muds, slurries, fresh concrete or magmas.