Influence of Natural Minerals in the Filler Fraction on Hydration and Propertiesof Mortars

摘要

Natural mineral fillers generally comprise a significant part of the constituencyof cement-based materials. An increased understanding of the interaction between cement and natural mineral fillers is thus considered important. The effect of mineralogy of fillers on the hydration behavior and certain properties of cement-filler mortars has been studied in the present work. The minerals studied were calcite, quartz, orthoclase, albite, anorthite and wollastonite. The results showed that the presence of these minerals generally accelerated the early cement hydration. Calcite and wollastonite tended to reduce the length of the induction period and calcite appeared to increase the hydration rate during the acceleratory period. Anorthite increased the third major heat peak. The other minerals influenced the hydration behavior to a much lesser degree. Possible mechanisms leading to the different hydration kinetics are discussed. The workability of the mortars appeared to be positively influenced by the presence of calcite, wollastonite and anorthite. The presence of the other minerals had little effect on the workability. Wollastonite possess tensile strength enhancement properties for cement-based materials.