Studying the effect of mineral additives on the properties of heat-resistant concrete on slag-lime binder

This research work is devoted to the study of the effect of mineral additives on the properties of heat-resistant fine-grained slag-lime concrete with fire clay aggregate. To conduct the study, self-decaying ferrochrome slag, mixed with the NaOH water solution, is used as a slag-lime binder. Mineral additives of different nature and chemical composition were introduced in the amount of 10 % and 20 % instead of self-disintegrating ferrochrome slag. As a result of the work it was revealed, that the use of the kaolin and reactive alumina additives allows to obtain heat-resistant concrete with high residual strength and heat resistance. Besides that, kaolin provides an increase of the concrete durability after heat treatment, and the use of reactive alumina allows to receive heat-resistant concrete with the И13 class of the maximum permissible temperature of application. In this regard, the development of kaolin- and reactive-alumina-based complex modifier for slag-lime heat-resistant concrete seems to be relevant. Also, to identify the action mechanisms of mineral additives in the future, it is necessary to conduct research of the phase composition and structure of the modified slag-lime stone using physical and chemical methods of analysis.