The work is dedicated to research of the thermal stresses state of massive concrete and reinforced concrete structures in construction period. The article examines the results of the analysis of the thermal stress state, which occurs in massive concrete ground slab with thickness of 1 m. The study was conducted with using analytical models, which include the factor of diurnal temperature range in comparison with simplified methods. Authors established that solving the problem of thermal stressed state of the massive foundation slabs in the building period without taking into account the influence temperature changing during the month might not cause to significant deviation of the real diagram of the thermal stresses and elongation deformations in the structures body: error is less than 0.5%.

Concrete is a fundamental material of modern construction due to its reliability, the ability to harden in air and under water, the ability to build structures of any shape and sizes. In particular, it is used in the construction of advanced structures and their parts: nuclear power plants, large hydraulic struc-tures, bridges, massive foundations of multi-storey buildings, etc. This paper is devoted to relevant objective in the field of construction of buildings and structures with a high level of responsibility, the study of thermal crack resistance of massive concrete structures, taking into account the temperature effects during the building period. The calculations are given of the thermal crack resistance of the foundation plate of the reactor department of Leningrad NPP-2 under continuous concreting with one block at full height. It is highlighted that the use of the simplest calculation model, which does not con-sider fluctuations in air temperature during the building period, leads to a significant error of the sur-face insulation thickness that is optimal from the point of view of providing the thermal crack re-sistance of a massive concrete structure.

Energy conservation and improving energy efficiency are priority areas for the development of the global economy. The need to increase the energy efficiency of the engineering equipment of buildings is due to both the requirements to reduce the energy consumption of buildings in general, and the increase in the proportion of energy-consuming climate systems used in modern construction. In large modern office, hotel and residential complexes to achieve the greatest energy efficiency it is necessary to use various technical solutions. The main element of an energy-efficient heating system is regulation. Balancing devices allow to not only balance and tune the system at any time of operational period but also serve as stop valves during reparation and diagnostics. Determination of energy savings bases on the average value heat consumption before and after modernization, depending on the type of installed valves or their combination. The focus of the work is hydraulic calculation of the heating system the authors conduct research on the effect of differently balancing fittings on the hydraulics of the heating system.

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