All fresh pastes were rheologically characterized in order to study the
effect of the water and fly ash contents on their viscosity and hence, their
flowability and water demand. All pastes showed a shear thinning behavior.
Fig. 2a and b show the viscosity values vs. w/CSA and w/b contents,
respectively, for all the pastes grouped according to their fly ash
content (0, 15 and 30 wt.%). All the values were taken from the upcurve
at the shear rate of 30 s−1
. Note that the viscosity of an additional