Yield stress and bleeding of fresh cement pastes

We focus in this paper on a potential correlation between yield stress and bleeding. We suggest that the conditions under which a fresh cement paste is able to display a yield stress result from the competition between Brownian motion and colloidal interactions whereas the conditions under which the suspension is stable result from the competition between colloidal interactions and gravity. These competitions highly depend on the solid volume fraction of the system and on the polymer surface coverage. The correlation between yield stress and bleeding is therefore very indirect and difficult to use in practice.