Modelling Thixotropic Behavior of Fresh Cement Pastes from MRI Measurements

From MRI measurements, the authors 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 the usual yield stress model: the transition from the solid to the liquid regime is abrupt. A simple thixotropic model is proposed based on these observations. The validation is done on the steady and transient state on local experimental tests. A local rheogram is developed 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.

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  • English

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  • Accession Number: 01099405
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 5 2008 12:19PM