Development of a rheological testing protocol for cement paste

This work develops and analyzes the outcome of several practical experiments in order to propose a protocol to measure cement paste properties in a parallel plate rheometer. The observed parameters are: the shear rate, the shear stress, the viscosity and the density. The protocol was developed considering preparation of the cement paste, preservation of the mixture, interval of measurement and shear rate sequence. The rheometer employed was an Anton-Paar rheometer model MCR301 pared with the cross-hatched stainless-steel parallel plates PP25 P2, the preparation protocol of the samples was based on the standard ASTM C305, and the density of the mixture was measured by the procedure UNI EN 1097-7: 2000. The obtained result of each experiment was compared to the theoretical Bingham model, for the confirmation of the cement paste as a Bingham fluid, taking into the consideration the relation among shear stress, dynamic yield stress, plastic viscosity, and shear rate. As the outcome of those experiments we propose a protocol that can be applied to measurement of cement paste rheology properties allowing the reproducibility of the measurements for virtually any cement paste mixture.