Influence of calcareous fly ash on rheological properties of cement pastes and mortars

The use of mineral additives allows modifying properties of concrete and results in substantial economic benefits. The research presents the influence of calcareous fly ash volume and degree of activation by grinding on the rheology of cement pastes and mortars. The rheological parameters of cement pastes and mortars were determined using a rheometer Viskomat NT. The results show that due to rheological properties of mixes calcareous fly ash (W) can be used as a cement component, however, after the activation and preferably in the multicomponent cement together with siliceous fly ash (V) or ground granulated blast furnace slag (S). Due to the workability, calcareous fly ash (as a type II additive) should be used after activation by grinding or by separation, preferably in an amount of not more than 20%.