ABSTRACT
The chapter analyzes effectiveness of using complex mineral admixtures in concrete mixtures, including metakaolin, as well as fly ash in self-compacting reaction-powder concretes. Calculated dependences for determining the influence of admixtures in combination with other composition factors on structural features of reaction-powder concretes and their physical and mechanical properties are given. Analysis of calculation methods for selection of aggregates grain size composition providing their required density is presented. The influence of a complex ash-metakaolin admixture on characteristics of cement stone hydration with additional introduction of superplasticizers is described. The effect of fly ash and metakaolin on water demand, compressive strength and flexural strength at different times of reaction-powder concrete hardening is compared with that of microsilica and blast furnace slag admixtures, as well as their composition. To predict the influence of technological factors on the main properties and composition design of reaction-powder concrete containing ash and metakaolin, experimental statistical models were obtained. The chapter provides their analysis and presents examples of possible use. Along with the influence of the studied mineral admixtures on concrete properties during normal hardening, results of tests at various temperatures and heat treatment duration are given.
