A comparative analysis of concrete samples without chemical additives and three concrete samples with additives was carried out The first sample contains the liquid additive, the other two contain the powder additive. The article aims at finding out the effectiveness of additives influence on the physical and mechanical properties of concrete and the basis for the application areas of modified types of concrete. By means of laboratory tests, the physical and mechanical properties of concrete mixtures are determined. To determine the strength characteristics of concrete samples, the IM-1250M testing machine was used. The tests were carried out under the same temperature and humidity conditions. According to the results of the experiments, the samples with the multifunctional additive "D-5" showed the best characteristics of concrete, and the samples with the dolomite flour additive were the cheapest. As a result of the experimental analysis, the effects of three additives on the strength characteristics of concrete and water resistance were determined. Cemplast and D-5 additives are highly effective modifiers of concrete and mortar. They can increase the strength by 20-40% at the age of 28 days at dosages of 1.6-6% with a decrease in water-cement ratio and a decrease of cement amount by 20%. Additives highly increase the workability of the mixture, air entrainment and water resistance. While using the chemical additives an early set of the concrete design strength is observed for the construction time reducing in 7 days.

A comparative analysis of concrete without additives and concrete samples containing molybdenum wastes was carried out. The purpose of the work is to identify the effectiveness of the metallurgical waste influence on the physicomechanical properties of concrete, the transportation from the storage site to the concrete plant, and the substantiation of their application areas. This will solve a twofold problem: to solve the problem of industrial waste (by improving the environmental status on the example of North Ossetia-Alania) and expand the range of additives used in the production of concrete. By conducting laboratory tests the physical and mechanical properties of concrete mixtures are determined. To determine the strength characteristics of concrete samples, the IM-1250M testing machine was used. The tests were carried out under the same temperature and humidity conditions. According to the results of the experiments, the samples with molybdenum-scheelite waste showed a higher result of the physicomechanical properties of concrete. As a result of experimental analysis, the influence of metallurgical industry wastes on the strength characteristics of concrete and water resistance, as well as the safety of their use in concrete mixtures, was determined. The use of waste from the metallurgical industry will save natural material, and at the same time clear large areas of these dumps. The use of waste from the metallurgical industry will save natural material and reduce transportation costs, as there are concrete plants near the dumps, which are economically feasible. Thanks to that use it is possible to clear the large territories of these dumps.

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