Parameters of hardened concrete with the addition of metakaolin

Abstract

There is currently no known one recipe for a concrete mix that would be suitable in all operating conditions. At present, in addition to the basic ingredients, mineral additives and chemical admixtures can be found in the formulas of concrete mixes. Each intentionally introduced addition to the concrete mix affects the rheological characteristics of the concrete mix as well as the parameters of hardened concrete. The use of mineral additives replacing cement and aggregate in a concrete mix should contribute to environmental protection in a simple and economical way. If, in addition, additives are by-products of industry, they should be managed. Alternatively, one should look for possibilities of their neutralization, eg in the concrete industry. The article applies to laboratory tests of concretes with the addition of 0%, 10%, 20%, 30% metakaolin. The additive was replaced with cement in a concrete mix. The effect of the additive on compressive strength, water absorption and capillary rupture of concretes was investigated. Compressive strength was tested after 14, 28, 56 and 90 days. Water absorption and capillary rupture was tested after 28, 56 and 90 days.