Expanded clay concrete differs from heavy-weight concrete not only by the composition and performance properties, but also by modes of chemical interactions between the components. So, not the primary problem of reinforcement corrosion in heavy-weight concrete under the normal conditions and the correct protective layer, becomes in the major problem in expanded clay concrete. The issue of reinforcement corrosion in expanded clay concrete is considered in this article. The studies on the effect of different compositions on the corrosiveness were conducted. Researchers have proposed various options for expanded clay concrete reinforcement protection from the environmental impact, including those through a variety of chemically active additives. According to the data obtained by experimenting, the diagrams of corroded area size dependence on various factors were presented.The results of the studies conducted are the recommended design and technological measures for the reinforcement protection against corrosion in various fine aggregate-based (natural sand, ash and dry hydroremoval) light-weight expanded clay concrete. Thus, the minimum concrete protective cover for main and distribution reinforcement of external walls must be at least 25 mm. It is necessary to inject additives -reinforcement corrosion inhibitors (sodium nitrite, sodium tetraborate) to the concrete composition. The consumption of cement, and hence, the cement paste content of concrete mixture must be not lower than 220 kg/m 3 , and under the application of the active dry fly ash removal À200 kg/m 3 .

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The paper considers the possibility of using slag concrete in underground construction. Technological parameters for production of slag concrete with the set properties are defined. The influence of the composition of slag concrete used in the conditions of mine construction on the change of physical and mechanical characteristics, durability and stability is determined. The limits of technological parameters of slag concrete preparation are established. The possibilities of combined use of blast-furnace slags and clinkers for concrete in mine construction are substantiated. The chemical composition of blast furnace slag and the possibility of its application in the composition of concrete is described, the interaction of an aggregate - Portland cement with blast furnace slag is studied. The technique for conducting experiments to determine the rate of strength gain of different types of concrete is described. The rate of strength gains of heavy concrete and the rate of strength gain of slag concrete with additives and without additives have been compared. The possibility of application of this slag concrete in the process of concreting with the use of sliding formwork has been studied.

The article discusses the possibility of using coal waste for the preparation of mine concrete. As a result of the research, scientific and prac- tical results were obtained. It has been experimentally proved that when a small fraction of coal, which is a waste of coal mining, is added to mine concrete, the strength of concrete decreases, but with a certain ratio of this strength it is sufficient to ensure the required properties. A series of experi- ments was carried out with the addition of liquid glass to the concrete to control the setting time of the mixture. The properties of coal wastes were determined and the possibility of their use in mine concrete was investigated. It has been established that the introduction of a fine fraction of coal in the optimum quantity into the composition of mine concrete is possible without reducing technological parameters.

The possibility of using expanded clay sand in surface and underground mine construction is considered in the article. As a result of the research, the material properties were studied, its uses were determined. The research has experimentally proven that expanded clay sand can be used as a base for concretes and mortars, which are suitable for mine construction by their properties. In the course of the research, samples of various compositions were made; the structure of the material is shown. Samples were tested to determine several physical and mechanical properties. Based on the experimental data, it was concluded that expanded clay sand can be used for mine construction projects, providing strength and heat performance of structures.