Rheological properties for fresh cement paste from colloidal suspension to the three-element Kelvin–Voigt model

Abstract

In the present work, rheological behaviors of fresh cement paste are studied based on multi-disciplinary approaches, i.e., colloidal suspension using attractive van der Waals force, rheology using the Bingham model and Bingham–Papanastasiou model, which are able to describe the behavior of cement pastes before and after yield stress, and finally the continuum mechanics based on Maxwell and Kelvin–Voigt models. To achieve this, the fresh cement paste with different water-to-cement ratios of 0.3 up to 0.6 is prepared. The attractive van der Waals forces are estimated based on the distances between solid cement particles, which vary at every single water-to-cement ratio. The rheology experiments of all water-to-cement ratios are performed using a rheometer. According to our experimental outcomes, the Bingham and Bingham–Papanastasiou models are applied in the modeling of the experimental curves and determination of yield stress and viscosity. Maxwell and the Kelvin–Voigt models are utilized in describing solid-like behavior before yield stress and fluid-like behavior beyond yield stress. It is observed that the increase of water generates a decrease in the viscosity, yield stress, and packing concentration of solids. It also increases the distances between two cement particles in the cement pastes. According to the modeling results, the Bingham–Papanastasiou model is well adapted for the cement paste flow due to its additional modeling parameter, which is known as m. The role of m is understood and described by linking the van der Waals interaction, rheology, and three-element Kelvin–Voigt model as a whole in function of water-to-cement ratio. m is understood as a key parameter in which the distance between particles affects the rheological behavior of fresh cement pastes. Lastly, the two-phase flow simulations have been successfully achieved and compared with the experiments. The conclusion and outlooks are summarized and discussed at the end of the paper.