Dosage of Metakaolin in High Performance Concrete

摘要

This article deals with optimal dosage of metakaolin as addition in high performance concrete. The main criteria for assessing the optimal dosage of metakaolin were compressive strength, rheological behaviour and economic benefits. Metakaolin was added to the mixture of high performance concrete in the range from 0 to 25% of cement weight. The comparison of metakaolin and microsilica, which is often used by concrete producers due to its excellent properties are also performed in this article. The experiments demonstrated that the use of metakaolin as addition in high performance concrete affects positively the compressive strength and rheological behaviour. While the compressive strength increased especially at the lower doses of metakaolin and it remained unchanged at the higher doses, changes in rheological behaviour were most obvious at the higher doses. From this point of view, it is possible to recommend higher doses of metakaolin.