Viscosimetry of cement pastes - Analytical and numerical solutions

The paper briefly summarizes theory needed for analytical and numerical solutions applied in viscosimetry of cement pastes. Practical lab or field tests (such as slump-flow tests) are compared with viscosity characterization in a rotational rheometer. Analytical solutions and numerical approaches are verified on experimental data gained on three different mixtures varying in water to binder ratio and in the presence of an additive. It was found that simple analytical estimates are not appropriate in most cases. Numerical models are highly dependent on the constitutive parameters that are extracted from rheometers. Two simple model variants were studied and conclusions on the suitability of the models drawn for the cement pastes. In specific cases (simple cement pastes without additives) the agreement with experimental data was found. For a cement paste with thixotropic additive simple models fail and other more complex model would be appropriate.