The flow properties of mortar conform to the Bingham model and mortars require two parameters, the yield stress and plastic viscosity, to be measured in order tomake an unambiguous definition of their rheology. This paper describes the use of commercially available instruments to determine these two parameters. Yield stress and plastic viscosity are affected by the nature and relative proprtions of cement, sand, water and admixtures in complex ways which are, however, broadly similar to the effects seen in fresh concrete. As a result the instruments are potentially useful in quality control, selection of raw materials, formulation of mixes and assessment of the suitability of the mixes for particular applications.
- rheological methods
- flow properties