Abstract
When the utilization volume of industrial wastes and by-products in cement plants are increased, it is necessary to control the fluidity of cement containing a large amount of aluminate phase. In my research I investigated the fluidity and the initial hydration of cement containing a large amount of aluminate phase added limestone powder, anhydrite and hemihydrite. Cement clinkers were synthesized from industrial raw materials and reagents by using an electric furnace in laboratory. The aluminate phase contents of clinkers were about 8 mass％ and 12 mass％. Cement pastes were prepared adding polycarboxylate type superplasticizer under water-cement ratio was 0.32. Apparent viscosities of the cement pastes were measured with a concentric-cylinder type rotational viscometer. The fluidity of the cement paste containing aluminate phase of 12 mass％ increased as the amount of hemihydrite increased. On the other hand, it decreased as the amount of anhydrite increased. No matter what kind of gypsum was added, the limestone powder was able to improve the fluidity of cement paste containing a large amount of aluminate phase. These results are not correlated to relation between adsorption of polymer per unit area and apparent viscosity. But the apparent viscosities of the cement pastes were associated with the heat generation rates of the cement pastes. As a result, the fluidity of the cement paste containing aluminate phase of 12 mass％ was improved by adding limestone powder more than 10 mass％ and anhydrite 4 mass％.
