Analytical solutions for bleeding of concrete due to consolidation

The bleeding of cement pastes, cement mortars, and concrete is due primarily to the self-weight consolidation of the granular skeleton formed by the solid constituents thereof. However, the effects of hydration can end this process prematurely. Linear finite- and small-strain analytical solutions of bleeding as a consolidation process that account for the effects of hydration are presented and then validated by comparison with laboratory data for cement pastes and concretes. Contrary to earlier assertions that a finite-strain model is required to model bleeding, the new finite- and small-strain solutions model the bleeding of the relatively shallow specimens analysed equally well. However, further research is necessary to establish whether small-strain solutions can model adequately the bleeding of comparatively deep concrete layers, and methods of determining the values of input parameters for the new solutions are also required. A potential method of determining one of these, the time of set, is discussed briefly. (C) 2010 Elsevier Ltd. All rights reserved.