Journal Articles Applied Rheology Year : 2013

Assessment of penetrometry technique for measuring the yield stress of muds and granular pastes

Abstract

We discuss the possibility of using penetrometry technique for measuring the yield stress of concentrations made of grains immersed in a colloidal phase, such as concrete or muds. In that aim we used model materials made by suspending glass beads at different concentrations in a kaolin-water paste. We then show that a uniform shear stress develops along the object (plate or cylinder) beyond the entrance length. This shear stress plotted versus the object velocity exhibits a shape similar to the flow curve of the material determined from rheometry. For materials exhibiting the typical flow curve of a simple yield stress fluid, i.e. at bead concentrations smaller than 30 %, the stress associated with an inflection point located at low velocities of this curve appears to correspond to the material yield stress. At larger concentrations of beads the suspensions have a more complex behaviour likely affected by its granular nature at a local scale and the possibility of migration or frictional effects, so that neither conventional rheometry nor penetrometry provide relevant data. We conclude by describing two practical penetrometry techniques for precisely measuring the yield stress of simple pastes.

Domains

Materials
No file

Dates and versions

hal-00946074 , version 1 (13-02-2014)

Identifiers

Cite

M. Tikmani, J. Boujlel, Philippe Coussot. Assessment of penetrometry technique for measuring the yield stress of muds and granular pastes. Applied Rheology, 2013, 23 (3), ⟨10.3933/applrheol-23-34401⟩. ⟨hal-00946074⟩
101 View
0 Download

Altmetric

Share

More