75504 2712-8172 Magazine of Civil Engineering 8 60 2015 1-82
CHR RUS 3-6 Peter the Great Saint Petersburg Polytechnic University Yakubson Vera engstroy@inbox.ru
Polytechnicheskay, 29
 IX International congress “Energy efficiency. XXI century” The congress “Energy efficiency. XXI century. Engineering methods for reducing the energy consumption in buildings” took place in St. Petersburg on 11 November 2015. The article describes the main reports of the plenary meeting, primarily devoted to the Russian laws in the energy saving field. Furthermore, the summary of reports of the section “Building thermophysics: increasing the energy efficiency of residential and public buildings during the major repairs and reconstruction” is given. 10.5862/MCE.60.1 energy efficiency buildings construction energy saving conference Russian laws building envelope thermophysics major repairs https://engstroy.spbstu.ru/article/2015.60.1/ 01.pdf
RAR RUS 7-19 Peter the Great Saint Petersburg Polytechnic University Nikolskiy Sergey big_panda16@mail.ru
Polytechnicheskay, 29
 Peter the Great Saint Petersburg Polytechnic University Pertseva Olga olya_perceva@mail.ru
Polytechnicheskay, 29
 Peter the Great Saint Petersburg Polytechnic University Ivanova Viktoriia Viktoriaviktoriaaa@mail.ru
Polytechnicheskay, 29
 Substantiation of an express-method for determining the freeze-thaw resistance of cellular materials An express method for determining the freeze-thaw resistance of cellular materials was offered and substantiated in this article. The proposed measurement technology of concrete frost resistance is based on the computation of the value z which is the ratio of the relative decrease of compression resistance R to the relative permanent set ε in the direction which is perpendicular to the pressure. It was found that this ratio is constant for a given composition of the concrete and does not depend on the values of R and ε. It was also proved that the values are not sensitive to the replacement of mechanical thermal cycles. These aspects will decrease the time for determining the freeze-thaw resistance of concrete and reduce the labor intensity of the tests conducted. The proposed method has been implemented on 10 samples of concrete with the following composition: Portland cement 400 (12.3 %), sand (24.7 %), granite macadam of dimensions 5…20 mm (55.6 %), water (7.4 %). Specimen cubes, according to the proposed method, were saturated with water, measured, subjected to alternate freezing and thawing and axial compression to achieve extreme loads. Then the frost resistance for each sample and the mean sample value F were calculated. The resulting value was compared with the freeze-thaw resistance, which was received for the mixture by the basic method. Thus, a new accelerated method for the determination of the freeze-thaw resistance of cellular materials was substantiated. It is highly efficient, simple, and has a low cost. 10.5862/MCE.60.2 freeze-thaw resistance cellular material concrete thermal cycling permanent set compression resistance nondestructive method https://engstroy.spbstu.ru/article/2015.60.2/ 02.pdf
RAR RUS 20-29 Peter the Great Saint Petersburg Polytechnic University Zubkov Sergey svzubkov@mail.ru
Polytechnicheskay, 29
 Peter the Great Saint Petersburg Polytechnic University, PRDI “Venchur” Ulybin Alexey ulybin@mail.ru
Polytechnicheskay, 29
 LLC "OZIS-Venture" Fedotov Sergey fed87@mail.ru
4/1 Vavilovyh St., St. Petersburg, Russia, 195257
 Assessment of the mechanical properties of brick masonry by a flat-jack method The modern Russian methods for defining the mechanical characteristics of brick masonry are based on finding the strength of masonry components (brick and mortar). After getting the results of laboratory tests of components, mechanical characteristics of masonry are calculated using empirical formulae. Those formulae, however, cannot take into consideration the presence of damages and other factors. Obtaining the characteristics (strength and deformation) by a direct flat-jack test of masonry fragments on-site looks promising. A widespread use of FEM requires setting accurate deformation features for modeling domes, arches and thin brick outside layer in multilayer walls. Also accurate deformation characteristics are used for calculating temperature loads. The paper gives the results of practical use for the masonry deformation research by the flat-jack test method. The correlation factors are defined and rigidness coefficients of flat-jacks are obtained in the study. 10.5862/MCE.60.3 masonry testing flat jack brick masonry deformation sensor stiffness of the jack elastic modulus strength of masonry https://engstroy.spbstu.ru/article/2015.60.3/ 03.pdf
RAR RUS 30-37 57189360151 0000-0001-6867-4050 West Pomeranian University of Technology Szczecin Orlovich Romuald orlowicz@yandex.ru
al. Piastów 17, 70-310 Szczecin, Poland
 Branch of RUE Institute BelNIIS – Scientific-technical Centre Derkach Valeriy v-derkatch@yandex.ru
267/2, Moskovskaya str., Brest, 224017 Belarus
 Peter the Great Saint Petersburg Polytechnic University Zimin Sergej zimin_sergei@mail.ru
Polytechnicheskay, 29
 The damage of a stone facing layer at the junction with reinforced concrete floors The article provides an analysis of the technical state of a stone facing layer of two-layer facade walls of monolithic buildings at the junction with reinforced concrete floors. The results of the numerical investigations of the stress-strain state of floor-by-floor supported multilayered walls with a facing layer at temperature influences are given. The analysis of the resistance of the facing layer of the wall to temperature effects, taking into account the deformation characteristics of mortar joints, was carried out. It was shown that the use of high-quality mortars in the facing layer increases the compressive stress on its contact with the slab. 10.5862/MCE.60.4 frame buildings multi-layer wall facing layer mortar type temperature effects https://engstroy.spbstu.ru/article/2015.60.4/ 04.pdf
RAR RUS 38-43 Branch of RUE Institute BelNIIS – Scientific-technical Centre Derkach Valeriy v-derkatch@yandex.ru
267/2, Moskovskaya str., Brest, 224017 Belarus
 Wind load resistance of multilayer walls supported floor-by-floor with a facing layer The article describes a method for checking the ultimate limit state of multilayer walls supported floor-by-floor with a facing layer under wind loads. We have conducted an analysis of the resistance of the multilayer wall structure to wind effects, taking into account the strength and deformation characteristics of the cladding and core layers, and the conditions for securing the masonry wall to the frame structure. It was shown that the use of a base layer for multilayer walls with brick veneer masonry with a low modulus of deformation, and the lack of consolidation of the base layer to the support increase the overlap of bending moments in the facing layer. It was found that the onset of the ultimate limit state of multilayer walls which base layer is made of 300 mm-thick porous concrete blocks is determined by the resistance of the masonry cladding layer to wind loads. Proposals for the design of multilayer walls with supported floor-by-floor with a facing layer of brick were formulated. 10.5862/MCE.60.5 frame buildings multilayer wall cladding layer core layer calculation models ultimate limit state https://engstroy.spbstu.ru/article/2015.60.5/ 05.pdf
RAR RUS 44-55 Poltava National Technical Yuri Kondratiuk University Leshchenko Maryna leshchen_m@mail.ru Poltava National Technical Yuri Kondratiuk University Semko Volodymyr syom@mail.ru Thermal characteristics of the external walling made of cold-formed steel studs and polystyrene concrete The paper proposes to use polystyrene concrete as an insulating material in wall panels made of light gauge studs. It should solve the problem of thermal bridges in such panels. The strength and the heat conductivity factor for polystyrene concrete with the density of 300-1300 kg/m3 were determined. Results showed that by increasing the density of polystyrene concrete by 4.1 times the thermal conductivity is increased by 3.7 times, which is an almost linear relationship. For instance, the strength at a density of 300 kg/m3 is 0.25 MPa, while at a density of 1300 kg/m3 it is already 8.2 MPa, which is 30 times more. For samples of different density, a scattering of deformations under compression was recorded. A full deformability of PSC cubes of 1292 kg/m3 density was on average 1 mm, while for 309 kg/m3 cubes it was 10 mm, indicating a larger deformability of low-density polystyrene concrete. The experimental samples of wall panels were assembled and their heat-transfer resistance was measured in the laboratory. It was found that the presence of thermally conductive inclusions in the wall structure reduces heat resistance up to 50 %. It was proposed to use profiled sheeting as an external wall covering. Besides, it is necessary to design the wall so that the external flange of the sheeting is placed across the heat-conducting inclusions. The gap between the profile and the sheeting is filled with polystyrene concrete and serves as thermal pad. This method of increasing energy efficiency of coldformed steel and polystyrene concrete wall structures is purely structural and does not require additional costs. By increasing the web height of the profiled sheeting, the effect of heat conducting inclusions is reduced in direct proportion – by 40% at 20 mm, by 20% at 40 mm and by 10% at 50 mm. The proposed method is theoretically and experimentally proven. 10.5862/MCE.60.6 buildings construction energy efficiency light-gauge steel stud cold-formed steel polystyrene concrete thermal conductivity strength. https://engstroy.spbstu.ru/article/2015.60.6/ 06.pdf
RAR RUS 56-67 Khakass Technical Institute – branch of Siberian Federal University Portnyagin Denis my4455@yandex.ru Improving the thermal performance of the building envelopes with the use of foam glass-ceramics Recommendations on eliminating the defects of thermal insulation on the basis of the previously carried out thermal imaging surveys were given. Constructive solutions of building envelopes were proposed with regard to modeling thermal fields in ELCUT. A typical solution of thermal insulation of the basement joint is the unit exterior insulation of the basement wall to the level of the facing course bottom. This constructive solution is characterized by a significant thermal bridge, in the direction through the cross-section of the floor slab under the insulation of the wall. The article presents the results of eliminating the thermal bridge by substituting of ceramic or silica bricks for thermal insulation bricks of foamglass. We discussed the roof and parapet joint. The paper also presents the results of heat loss calculation when replacing of the top line of backfills above the level of the coating by the brick thermal insulation made of foamglass. 10.5862/MCE.60.7 energy performance heat loss building envelope foam glass foam glassceramics https://engstroy.spbstu.ru/article/2015.60.7/ 07.pdf
RAR RUS 68-82 15730895100 http://orcid.org/0000-0003-3251-3356 Saint Petersburg State University of Industrial Technologies and Design Gorshkov Alexander alsgor@yandex.ru
St. Petersburg, Russia
 Military Space Academy named after A.F. Mozhaysky Rymkevich Pavel rymkewitch@yandex.ru A diagram method of describing the process of non-stationary heat transfer Heat transfer through the exterior building envelope in real operating conditions is always unsteady. However, in practice, in most cases, steady-state heat transfer is discussed, characterized by the time-constant magnitude of the heat flow rate and temperatures. The steady-state heat transfer equations are greatly simplified. This makes it practical for developing engineering calculation methods. Modes of non-stationary heat transfer also find practical application. However, these methods have a number of problems. The authors proposed a method for solving the modes of unsteady heat transfer, based on probabilistic methods of the general theory of transference. The paper considers the heat flow rate through a flat building envelope consisting of several successive layers. We showed how the order of the layers in the composition of the multi-layer building envelope affects its thermal stability. We obtained an equation for determining the difference between the average times of passage of heat flow through the building envelope at various layers of disposition. 10.5862/MCE.60.8 buildings construction building envelope heat flow rate heat transfer thermal resistance heat resistance thermal stability energy saving energy efficiency https://engstroy.spbstu.ru/article/2015.60.8/ 08.pdf