Bleeding of concrete as an ageing consolidation process

Bleeding of concrete results mainly from the self-weight consolidation of the granular skeleton. Simultaneous physical and chemical structural effects provoke the ageing of the skeleton. In addition, the displacements are large and the hydromechanical properties evolve locally with the porosity. All these phenomena are here addressed through an ageing nonlinear model accounting for the sample size effect experimentally observed on the bleeding capacity. The characteristic time scaling of the ageing effect is found to be dependent mainly upon the amount of cement in the mix-design and the temperature. It appears to be a key indicator for assessing the properties of fresh concretes and their evolution in time. (C) 2004 Elsevier Ltd. All rights reserved.