Effect of coarse particle volume fraction on the hydraulic conductivity of fresh cement based material
Résumé
Hydraulic conductivity or permeability isa key parameter that affects the stability of freshcement-based materials. For example, bleeding andwater retention are among the most important issuesgoverned by concrete permeability. Whereas thisparameter is relatively easy to measure at the cementpaste scale, it is difficult to evaluate with the additionof sand or gravel due to the sample size needed toobtain a representative sample. For ordinary permeabilitymeasurement, the test duration is linearlylinked to the sample height. The aim of this study isto relate the concrete permeability to the cement pastepermeability for various aggregate volume fractions inmortar or concrete. The proposed model uses anadaptation of Darcy’s law to compute concretepermeability from measured cement paste permeabilityand mix-design parameters. This model has beensuccessfully tested with kaolin and cement pastes withspherical aggregates (glass beads) and sand.