Introduction. Existing methods of reinforced concrete structures strengthening are very expensive and time-consuming. The development of new strengthening systems allowing to reduce time and cost of works is perspective and relevant task. Modern methods of strengthening with composite materials are insufficiently studied in Russia. Particularly if the behavior of composite materials in the reinforced concrete structures is concerned. The lack of research in this area leads to the overrun of materials and increase in the cost of structures’ strengthening. The aim of this work is to study the relative deformations of composite materials in the longitudinal and transverse directions during the operation of eccentrically compressed flexible reinforced concrete poles.

Materials and methods. The factual basis for the research are the results of experimental studies of the strength and deformability of eccentrically compressed reinforced concrete poles, strengthened with various types of composite external reinforcement. In the most loaded zones of the composite reinforcement, the 2 cm-long strain gauges were glued, capable of detecting changes in relative deformations up to 0.001 mm. In total, the results of operation of 5 poles were used in the analysis. During the experiment, deflections and relative deformations of concrete and composite materials were determined.

Results. In the result of experimental studies, relative deformations of composite materials in the longitudinal and transverse directions were obtained. The measurements were carried out at a stepwise increasing load equal to 10 % of the breaking load. Based on the data obtained, graphs of the dependence of the change in relative deformations on the load levels were plotted for each tested sample. In addition to the readings of strain gauges, deflections of tested samples were obtained during testing and graphically presented.

Discussion and Conclusions. The obtained experimental data on deflections and relative deformations in composite materials made it possible to determine the zones of the most and least strained sections of the composite reinforcement. Based on the analysis of these data, conclusions were drawn about the development of new strengthening systems that can significantly save the amount of composite materials used without reducing their efficiency.

Introduction. People’s growing needs in energy resources in conditions of resource deposits depletion makes it relevant the development of methods of enhancing buildings energy efficiency. The article notes the importance of increasing the level of energy efficiency by selecting a set of measures for the efficient use of energy resources at all stages of the life cycle. The analysis of Rostov-on-Don housing stock and positive trend in housing commissioning capacity growth in Russia point at the need to enhance the energy efficiency of buildings being under construction.

Materials and Methods. Energy efficient methods are as follows: the application of modern thermal insulation materials and "green" building technologies. The latter implies the approach to the design of buildings inferring minimized impact on the environment at all stages of the life cycle - from a building’s design to its elimination - including the application of "green" technologies: Smart Energy Glass windows, recuperators, solar panels.

Results. The results of energy-efficient technologies application were considered on the example of “Ostrovsky” residential compound being under construction in Rostov-on-Don. As a result the planned energy efficiency class B (high) was upgraded to A + (very high), which corresponds to one of the green building criteria.

Discussion and Conclusions. The use of energy efficient measures in construction of residential buildings allows to save considerable amounts of energy and resources at the stage of high-rise buildings operation, resulting in their energy efficiency class enhancement.

Introduction. Concrete is one of the materials most frequently used in construction thus the technologies of its manufacturing are being constantly improved. In our article we will develop the laboratory-made compositions of concrete based on the certain raw materials resources and restrictions existing at the construction site of one of the nuclear power plants in the Republic of Türkiye. One of the results of elaborating the concrete composition design technology is the selfcompacting concrete that fosters sustainable construction due to significant reduction of energy consumption. Self–compacting concrete is a type of concrete that can completely fill in the formwork only by gravity, without need for concrete consolidating by vibration. Its high fluidity and filling capacity are its advantages over conventional concrete. Self-compacting concrete has high fluidity, high water retention capacity, good strength. The aim of the study was to obtain the laboratory-made compositions of concrete based on the certain raw materials resources and restrictions existing at the construction site.

Materials and methods. The list of raw materials potentially meeting the design documentation requirements has been specified. The concrete compositions using various aggregates were selected, the minimum amount of cement was determined, aimed among other things at corrosion resistance improvement.

Results. Based on the restrictions existing at the construction site and according to the results of raw materials analysis including their oxide composition specification, 5 compositions were developed for each of NPP engineering structures.

Discussion and conclusions. The study has completed all the tasks set forth, the main of which are: analysis of the raw materials market, laboratory studies of raw materials, specification of their actual physical and mechanical properties, identification of components meeting the standards and requirements, obtaining the laboratory-made compositions of concrete mixtures classified by their designation. The perspectives for further research are indicated.

Introduction. The credible cost formation mechanism of a construction investment project’s life cycle stages is considered. The cost of the project depends on diverse components: the duly designed project, the cost calculation method, the choice of suppliers and contractors, the construction time frame, etc. All calculations are based on the estimated cost of the project made at the design stage.

Materials and methods. Transition to the input costing method turns to be an advancement in determining the estimated cost of construction at the design stage. The main problem here is the lack of a unified database providing the data on the cost of resources at the current price level for each region. The proposed solution is transferring the functions of replenishing the Federal State Information System of Pricing in Construction (ФГИС ЦС) database from the Ministry of Construction, Housing and Utilities of the Russian Federation to the regions of Russia.

Results. The transition to the input costing method will allow the regions to hold the information on the credible estimated cost of facilities planned to be built in the forthcoming years. The increasing amount of standard design projects will enable solving a number of cost management issues at the design stage. The projects that proved to be successful can be reused many times because all possible errors were debugged, the proposed solutions were tested on the facilities already built. The use of the standard design projects will allow to prepare and verify the project design documentation quicker. The time assigned for designing will reduce and no additional questions will arise in the process of construction. The application of information modeling technologies fosters the projects’ quality enhancement.

Discussion and conclusion. The mechanisms proposed by the authors will enable projects’ quality enhancement, reduce the cost and timing of design works, as well as make it possible to determine the credible cost of construction at the design stage, which is the basis for determining the volume of investment and calculating the cost of a facility at the stages of planning and implementation of the project.

Introduction. The mining of mineral deposits is related to the construction of sophisticated technological complexes on the surface being a liaison between underground operations and above-ground systems. During construction of the mining companies’ buildings and structures of the above-ground technological complexes there arise problems related to the complicated engineering, geological and hydrogeological conditions, as well as emerge difficulties caused by the presence of underground workings (mining, transport, ventilation, auxiliary) affecting the construction and operation of surface facilities. In this article a study was made of the stress-strain state (SSS) of a complex system comprising a mine surface building, a vertical shaft mouth with a ventilation duct under conditions complicated by the presence of subsiding soils and the need of reinforcement thereof.
Materials and methods. In the study there were used: the analysis of existing methods of soil bases reinforcement as applied to the specific engineering and geological conditions of construction, subject to the interdependence of aboveground and underground structures; the mathematical modeling of the system "a vertical shaft mouth with a ventilation duct - a subsiding soil mass reinforced with soil piles - a mine surface building’s foundations"; the study of SSS features on models, determination of the main factors affecting the design decisions on enforcement of soil bases and building foundations receiving a compound combination of operational loads.
Results. It has been found that the above-ground loadbearing structures, foundations and soil bases should be calculated taking into account the interdependence with the vertical shaft and the adjacent ventilation duct, based on the SSS parameters definition. The monolithic concrete mouth lining has a significant impact on the SSS of the foundation slab, increasing rigidity at the points of contact between the slab and the lining. The minimum vertical settlement of the slab is observed above the shaft mouth lining, the maximum - in the central part of the building, in the points of maximum load application.
Discussion and Conclusions. The results of the stress-strain state study of a reinforced soil mass and a vertical shaft mouth lining in interaction with the mine surface building’s foundations are formulated, and recommendations are given on considering the affecting factors when designing such facilities.