Modelling thixotropic behavior of fresh cement pastes from MRI measurements |
| |
Authors: | S. Jarny N. Roussel |
| |
Affiliation: | a Laboratoire d'Études Aérodynamiques (LEA) Université de Poitiers, ENSMA, CNRS, Boulevard Marie et Pierre Curie, Téléport 2, B.P. 30179, 86962 Futuroscope Chasseneuil cedex, France b Division Bétons et Composites Cimentaires, Laboratoire Central des Ponts et Chaussées, 58 boulevard Lefebvre, 75732 Paris cedex 15, France c Laboratoire Analyse des Matériaux et Identification, Institut Navier, 6 et 8 avenue Blaise Pascal, Cité Descartes, Champs sur Marne, 77455 Marne la Vallée cedex 2, France d Université Paris-Est, Institut Navier, 2 allée Kepler, 77420 Champs sur Marne, France |
| |
Abstract: | From MRI measurements we show that in a flowing cement paste thixotropic effects dominate over short time scales while irreversible effects become significant over larger timescales. The steady and transient flows exhibit a yielding behavior which differs from usual yield stress model: the transition from the solid to the liquid regime is abrupt. We propose a simple thixotropic model based on these observations. The validation is done on the steady and transient state on local experimental tests. We build the “local” rheogram which is representative of the intrinsic rheological properties. Comparisons with “apparent” rheograms demonstrate that it is possible to use correction techniques from the literature to have access to the real behavior law of the material from standard measurements but that, in the case of the material studied in this paper, this would nevertheless lead to an underestimation of the yield stress. |
| |
Keywords: | Rheology Cement paste Thixotropy Magnetic resonance imaging Model |
本文献已被 ScienceDirect 等数据库收录! |
|