Rheological models for cement pastes

Shear stress and shear rate data obtained for cement pastes were correlated by means of different rheological models. Pastes were prepared from a commercial Portland cement 325 at different water/cement ratios ranging from 0.34 to 0.42. Tests were performed at 25°C using a rotating coaxial cylinder viscometer. The investigation was accomplished by means of a hysteresis-cycles procedure. On the basis of the goodness of fit, the Herschel-Bulkley model seemed to be very effective for application to cement pastes.