The Influence of Mineral Admixtures on Rheology of Superplasticized Fresh Mortars
Appears on pages(s):
cement; mineral admixture; mortar; rheology; superplasticizer
The influence of fly ash, ground granulated blast furnace slag, and condensed silica fume on rheological properties of mortars with different cements and different new generation superplasticizers are presented and discussed. Rheological properties of these mortars were studied using Two-point workability test and these mortars can be considered as a model of concrete. The addition of mineral admixtures significantly influences rheological properties of mortars and the nature and range of this influence depend not only on the type, properties and content of mineral admixture but also on the properties of the cement and superplasticizer and interaction of these. The basic influence trends of mineral admixtures on rheology of mortars with polycarboxylate and polyeter superplasticizers are presented. It is concluded that the compatibility of cement and superplasticizer system should be selected taking into account presence and estimated dosage of given mineral admixture. The combined influence of given cement - mineral admixture - superplasticizer system on rheology of fresh concrete should be verified by means of experimentation. Two-point workability test made on mortars enables both selection of optimal cement - mineral admixture - superplasticizer system and collection of data for fresh concrete workability control.