Squeeze flow coupled with dynamic pressure mapping for the rheological evaluation of cement-based mortars

The squeeze flow test provides relevant information about the macroscopic rheological behavior of mortars. Nevertheless, the identification and characterization of micro and meso physical phenomena is necessary for a more thorough analysis. This work presents an experimental methodology that combines the squeeze flow test with a pressure mapping system for the rheological evaluation of cement-based mortars. Two compositions were analyzed, with and without viscosity modifying cellulose ether based admixture, and the liquid phase migration was quantified to support the interpretation of the results. The developed pressure mapped squeeze flow (PMSF) method allowed for reliable measurement of the evolution of the pressure distribution on the whole area of the squeezed sample, and the results were compared with theoretical models for different flow types and rheological behaviors. The presence of the cellulose ether admixture resulted in more homogeneous flows, which enabled bigger displacements and generated less fluctuations in the pressure distributions.