ABSTRACT
The Theological behaviour of plastic clay pastes can be identified using a simple compression test carried out on cylindrical samples. During very slow tests, hardening kinetic of plastic criterion occurs. The centre of sample dries up. In this case, an eulerian formulation of this biphasic flow problem is proposed. Mass balances for both skeleton and fluid are written. The relative speed of the fluid in the moving skeleton is expressed in terms of permeability and fluid pressure gradient satisfying Darcy’s law. The yield point is written in terms of void ratio using the Cam clay model. Total and effective stresses are expressed in terms of the yield point. Finally, a differential equation linking the spatial and temporal derivatives of the void ratio with the drainage parameters and skeleton characteristics is obtained and solved numerically. Several plastometer tests on mineral pastes validate the model and confirm the proposed numerical simulation.
