Correlating cement characteristics with rheology of paste

The influence of cement characteristics such as cement fineness and clinker composition on the “flow resistance” measured as the area under the shear stress–shear rate flow curve has been investigated. Three different types of plasticizers namely naphthalene sulphonate-formaldehyde condensate, polyether grafted polyacrylate, and lignosulphonate have been tested in this context on 6 different cements. The flow resistance correlated well with the cement characteristic (Blaine·{d·cC3A + [1 − d]·C3S}) where the factor d represents relative reactivity of cubic C3A and C3S while cC3A and C3S represent the content of these minerals. It was found to be either a linear or exponential function of the combined cement characteristic depending on plasticizer type and dosage. The correlation was valid for a mix of pure cement and cement with fly ash, limestone filler (4%), as well as pastes with constant silica fume dosage, when the mineral contents were determined by Rietveld analysis of X-ray diffractograms.