Influence of mineral additives on the rheological and strength properties of fine-grained concrete

Abstract

The paper considers 4 types of mineral additives for concrete - metakaolin, silica fume, wollastonite and zeolite - and their influence on the rheological properties and strength of fine-grained concrete, in which part of the cement is replaced by a mineral additive. It is shown that the replacement of 5-10% of cement with active mineral additives with a specific surface area 1.5 times or more greater than the specific surface area of cement (metakaolin, silica fume) leads to a decrease in the flowability of the mixture in proportion to the increase in the amount of additive in the system. When replacing 10% of cement with additives, the specific surface of which relative to cement is in the range of 0.88-1.2 (wollastonite, zeolite), on the contrary, increases the flowability of the mixture. The strength of all samples with mineral additives at 28 days of age was greater than that of the control composition. An increase in strength by 1.7-1.76 times is noted for compositions with the replacement of 10% cement with metakaolin, wollastonite or zeolite.