Magazine of Civil Engineering

RAR RUS 11601-11601 Sarhad University of Science and Information Technology Rizwan Muhammad rizwan.civil@suit.edu.pk

Peshawar, Pakistan

0000-0003-1275-8380 Department of Civil Engineering, University of Engineering and Technology Peshawar Ahmad Naveed naveed.ahmad@uetpeshawar.edu.pk

UET Peshawar, Pakistan

Department of Civil Engineering, University of Engineering and Technology Peshawar Naeem Khan Akhtar drakhtarnaeem@uetpeshawar.edu.pk

UET Peshawar, Pakistan

Seismic damage mechanism of weak beam-column joint frames The use of old building design codes and improper execution of recent seismic design practices resulted in substandard and vulnerable reinforced concrete building stock, the majority of which is built with weak beam-column joint connections (i.e. joint panels having no transverse reinforcement and built in low strength concrete). In order to understand the seismic response and damage behavior of recent special moment resisting frame (SMRF) structures with the defect of weak beam-column joints, shake table tests were performed on two 1:3 reduced scale two storey and one bay RC frame models. Reference code design and weak beam-column joint frame models were subjected to unidirectional dynamic excitation of increasing intensities using the natural record of 1994 Northridge Earthquake. The input scaled excitation were applied from 5 % to 130 % of the maximum input peak ground acceleration record, to force the test models from elastic to inelastic stage and then to fully plastic incipient collapse stage. The weak beam-column frame experienced flexural cracking of the columns, longitudinal bar-slip in beam members, cover concrete spalling and severe damageability of the joint panels under multiple dynamic excitations. The deficient frame was able to resist only 40 % of the maximum acceleration record as compared to the code design frame, which was able to resist up to130 %. Based on the experimental observations, a drift-based damage scale was developed for different performance limits states that can be employed for the global performance assessment of deficient weak beam-column joint RC frames. 10.34910/MCE.116.1 699.841 reinforced concrete structural concrete special moment resisting frame building frame beam-column joints shake table test progressive collapse https://engstroy.spbstu.ru/article/2022.116.1/

RAR RUS 11602-11602 57190161363 0000-0002-2328-6238 Ogarev Mordovia State University Nizina Tatyana nizinata@yandex.ru Ogarev Mordovia State University Balykov Artemy artbalrun@yandex.ru Ogarev Mordovia State University Volodin Vladimir volodinvv1994@gmail.com 7801669853 0000-0002-3413-247X National Research Mordovia State University Kyashkin Vladimir kyashkin@mail.ru

Saransk, Republic of Mordovia, Russia

Structure and properties of cement systems with additives of calcined clay and carbonate rocks Currently, one of the primary areas of technical progress in the field of construction is creating modern high performance concretes based on modified cement binders using various chemical and mineral additives that allow effective control of the structure formation and properties of material. The stock of the conventional additives for cement systems is failing to meet the increasing demand, which is related to territorial limitations and high cost of the most popular and efficient mineral modifiers (silica fume, metakaolin, fly ash, granulated slag, etc.). In this respect, thermally activated polymineral clays used as individual mineral additives and in complexes with carbonate rocks are promising for many regions of the Russian Federation, including the Republic of Mordovia. The paper presents results of studying the patterns in which mineral additives obtained on the basis of local raw materials of the Republic of Mordovia (calcined polymineral clay, dolomite and thermally activated mixture of clay and limestone) influence the technological characteristics of plasticized cement paste, phase composition and physical-mechanical properties of cement stone. Optimal dosages of mineral additives of calcined clay and thermally activated mixture of clay and limestone were identified: they did not exceed 19 and 12 % by binder weight, respectively. These dosages improved strength characteristics of cement systems in comparison with the control composition without the additives. X-ray powder diffraction established that using the developed mineral additives based on calcined polymineral clay and carbonate rocks increased hydration rate of Portland cement and allowed a targeted guidance of the cement stone phase composition: optimizing the ettringite concentration, reducing the number of the weakest and corrosion-exposed Portlandite crystals, increasing the density and strength of the bulk of calcium hydrosilicates by shifting the balance towards an increased content of highly dispersive low basic phases of C–S–H(I) type instead of high basic C–S–H(II) compounds. All of these factors determined the chemical efficiency of these mineral modifiers in cement systems. 10.34910/MCE.116.2 691.54; 691.3 cements additives calcined clay carbonate rocks mixtures hydration microstructure X-ray diffraction calcium compounds hardening compressive strength optimization https://engstroy.spbstu.ru/article/2022.116.2/

RAR RUS 11603-11603 57189462810 0000-0003-4905-7561 University of Balamand El-Mir Abdulkader abdulkader.elmir@fty.balamand.edu.lb

Kurah, Lebanon

35109560300 0000-0003-4729-5048 Budapest University of Technology and Economics Nehme Salem salem.nehme@epito.bme.hu

Budapest, Hungary

56589936700 0000-0002-2423-451X University of Balamand Assaad Joseph joseph.assaad@balamand.edu.lb

Kurah, Lebanon

Feasibility of concrete mixtures containing coarse and/or fine recycled brick aggregates This paper assesses the feasibility of concrete mixtures containing high replacement rates of fine and/or coarse waste brick aggregates. Three mixture series prepared with different water-to-cement ratios are tested for workability, compressive strength, split tensile strength, modulus of elasticity, water permeability (by capillary or under pressure), and drying shrinkage. Test results showed that the concrete properties remarkably degrade when the coarse natural aggregate fraction (i.e., retained on sieve No. 4) is fully replaced by recycled waste bricks, given their increased porosity that reduces the concrete density and weakens its skeleton. In contrast, the strength and durability remained almost unaltered when the fine natural aggregate fraction was replaced by 50 % recycled waste bricks, and considerably better than equivalent mixtures made using the same amount of recycled fine aggregates derived from hardened waste concrete. 10.34910/MCE.116.3 691.32 brick concrete aggregates durability mechanical properties recycling https://engstroy.spbstu.ru/article/2022.116.3/

RAR RUS 11604-11604 57222578800 0000-0001-6361-7153 University of Technology Al-Hammood Amer 42402@student.uotechnology.edu.iq

Baghdad, Iraq

57202301120 0000-0002-3667-0191 University of Technology Frayyeh Qais 40012@uotechnology.edu.iq

Baghdad, Iraq

57200942887 0000-0001-8287-2782 University of Technology Abbas Waleed waleed.a.abbas@uotechnology.edu.iq

Baghdad, Iraq

Iraqi bentonite as natural pozzolan In this study, Iraqi high-calcium bentonite was used for the first time to prepare natural pozzolan for concrete by the thermal activation method (calcination). Raw bentonite was calcined at 700, 750, 800, 850, 900, and 950°C for 30, 60, 90, and 120 minutes at each temperature. X-ray diffraction and quantitative X-ray diffraction techniques identified the optimal calcination program at 800°C for 90 minutes. In this program, calcination destroyed the crystal structure of bentonite-forming clay minerals, thus converting silicon, aluminium, and iron oxides into chemically reactive amorphous phases. The prepared natural pozzolan achieves a strength activity index of 108.3% at 28 days; additionally, it meets the requirements of the Iraqi specification of pozzolanic materials. The effects of Portland cement replacement with calcined bentonite at 5, 10, 15, 20, 25, and 30% were studied on selected properties of the cementitious binder and concrete. The results indicate that replacement percentage is positively associated with initial and final setting times and negatively correlated with the concrete slump. At seven days, calcined bentonite causes the decline of the compressive strength of concrete, while at 28 days, concretes containing 5, 10, and 15% develop higher compressive strength than the control mix. However, the compressive strength of concretes containing calcined bentonite differs from the control mix by not more than ±9% at 90 days. Calcined bentonite reduces the concrete splitting strength and density properties, and the absorption at 25% substitution or less. 10.34910/MCE.116.4 691.545 concrete bentonite montmorillonite thermal activation calcined clay cementitious materials pozzolan compressive strength strength activity index tensile strength fresh properties water absorption X-ray diffraction quantitative XRD https://engstroy.spbstu.ru/article/2022.116.4/

RAR RUS 11605-11605 St. Petersburg State University of Architecture and Civil Engineering Kaldar-ool Anay-Khaak oorzhaka-h@mail.ru 57191250155 0000-0002-7796-2350 St. Petersburg State University of Architecture and Civil Engineering Opbul Eres fduecnufce@mail.ru

St. Petersburg, Russia

Stress condition of orthotropic vault structure with cylindrical anisotropy This work considers analytical calculation of brickwork barrel vault, material structure of which has a pronounced variability of elastic constants. In normative documents, brickwork is considered as a complex two-component building material with elastoplastic properties. However, there are no clear recommendations that consider the variability of the elastic properties of brickwork. This article considers influence of anisotropic properties of a brickwork three-centered flat-arched vault on its stress condition on the basis of the elasticity theory. The calculation of a flat-arched vault is based on the classic theory of bending a curved curvilinearly-anisotropic beam in view of the properties of brickwork materials with cylindrical anisotropy. We cite a mathematical solution of a differential equation of fourth order in partial derivative with two variables for an anisotropic orthotropic body in polar coordinates for creation of mathematical models describing changes in the vault material elasticity modulus. Based on the solution to the curved orthotropic body anisotropy problem, we obtained correlations between elastic constants in the main anisotropy directions. 10.34910/MCE.116.5 624.074.3:539.3 barrel vaults brickwork anisotropy elasticity modulus elasticity constants stress condition https://engstroy.spbstu.ru/article/2022.116.5/

RAR RUS 11606-11606 55022875800 0000-0002-1708-0233 University of Balamand Arairo Wahib wahib.arairo@balamand.edu.lb

Kurah, Lebanon

0000-0001-6680-494X University of Lorraine Masrouri Farimah Farimah.Masrouri@ensg.inpl-nancy.fr

Vandoeuvre-lès-Nancy, France

0000-0001-9784-2818 University of Lorraine Abdallah Adel adel.abdallah@univ-lorraine.fr

Vandoeuvre-lès-Nancy, France

0000-0001-9271-7153 University of Lorraine Rosin-Paumier Sandrine sandrine.rosin@univ-lorraine.fr

Vandoeuvre-lès-Nancy, France

0000-0002-7163-9915 Advanced Construction Technology Services Sraj Omar omar.sraj@hotmail.com

Jeddah, Saudi Arabia

57202890131 0000-0002-0140-0941 ISSEA-Cnam Lebanon, Maurice Barres Khatib Milad milad.khatib@isae.edu.lb

Beirut, Lebanon

Temperature effects on the design parameters of a geothermal pile In geotechnical engineering, geostructures with thermo-active functions establish direct thermal exchange between the ground and buildings. They can transfer energy from or into the ground to heat or cool a building. However, adapting foundation piles, completely or in part, to produce energy piles results in heat exchange with the soil, which changes the temperature of the soil and could thereby and affects the geotechnical properties and load bearing capacity of the geostructure. Most calculations of the bearing capacities of deep foundations conducted in France are currently based on in-situ testing results using a pressuremeter. Using finite element method to model the pressuremetric behaviour of a compacted soil subjected to thermo-mechanical variations is the main motivation for this work. In this study, several pressuremeter tests were conducted on a compacted illitic soil in a laboratory tank at temperatures between 1° and 40°C. The impact of temperature variation on the limit pressure (Pl), the creep pressure (Pf) and the Ménard pressuremeter modulus (EM) were determined. The results showed a significant decrease for both limit pressure (Pl) and creep pressure (Pf) with the increase of temperature. Numerical simulations of these tests were used to calibrate a bilinear constitutive model, taking into account temperature effects on soil compressibility within a coupled thermo-mechanical framework. Thereafter, a case study of a heat exchanger pile was simulated using the proposed approach. 10.34910/MCE.116.6 624.154 geostructures pressuremeter heat transfer temperature conductivity finite element method https://engstroy.spbstu.ru/article/2022.116.6/

RAR RUS 11607-11607 0000-0002-8557-9925 Research Institute for Physical Chemical Problems of the Belarusian State University Bogdanova Valentina bogdanova@bsu.by

Minsk, Republic of Belarus

0000-0002-6702-7430 Research Institute for Physical Chemical Problems of the Belarusian State University Kobets Olga kobets@bsu.by

Minsk, Republic of Belarus

0000-0002-6241-1281 Research Institute for Physical Chemical Problems of the Belarusian State University Buraya Oksana fhp@bsu.by

Minsk, Republic of Belarus

Ustinov Andrey Peter the Great Saint Petersburg Polytechnic University Zybina Olga ozakata@mail.ru

Polytechnicheskay, 29

Intumescent compounds for fireproofing of polymer pipelines Reducing the rate of fire spread in buildings through the intersections of enclosing building structures with polymer pipelines is achieved by using fire clutches equipped with liners made of expandable materials. In case of a fire, it is ensured that the spread of flame through polymer pipelines is hindered due to formation of a heat-insulating foamed layer. This layer does not allow the polymer low-melting pipelines to heat up to 120°C. Comparative assessment of heat-insulating and mechanical properties of two intumescent composites and their charred products were carried out to clarify the reasons for their heat-insulating efficiency. Composites included the same intumescent system (ammonium polyphosphate / pentaerythritol / dolomite / thermally expanded graphite) and different polymer binders. The research was conducted using the following methods: complex thermal and X-ray analyses, scanning electron microscopy, a number of standard and original techniques. It was established that heat-insulating ability of a charred layer is determined by temperature intervals in which interactions of initial components occur. The best mechanical, heat-insulating and morphological properties of investigated intumescent composites and their charred layers are achieved when temperature ranges referred to formation of organo-mineral framework and volatile thermolysis products are coinciding. For the composites studied in this paper, this temperature range was 350–400 °C. Thanks to this knowledge, it becomes possible to develop new fire-retardant composites with improved properties instead of selecting the components in empirical way. As a result, the general quality of fire-retardant materials may grow and their properties will be sufficient not only to meet the construction requirements, but to properly operate in case of fire as well, practically justifying the predicted effect. 10.34910/MCE.116.7 699.812+691.175 fire clutch thermoformable composite polymer binder intumescent system foaming ability heat-insulating efficiency thermal analysis https://engstroy.spbstu.ru/article/2022.116.7/

RAR RUS 11608-11608 0000-0001-7516-3566 Peter the Great St. Petersburg Polytechnic University Golubev Ivan golubev2m@gmail.com

St.Petersburg, Russia

0000-0002-0455-1462 St. Petersburg State University Vlasov Dmitriy Dmitry.Vlasov@mail.ru

St. Petersburg, Russia

0000-0002-9840-0701 “B.E. Vedeneev VNIIG”, JSC Tsarovtseva Inga in_pilgrim@mail.ru

St. Petersburg, Russia

0000-0002-4291-2695 “B.E. Vedeneev VNIIG”, JSC Mayorova Margarita mayorovama@vniig.ru

St. Petersburg, Russia

0000-0003-0654-8651 LLC "Cribrol" Chipizubov Vitalii cribrol@mail.ru

St. Petersburg, Russia

57204708134 Peter the Great St.Petersburg Polytechnic University Shaposhnikov Nikita shaposhn_no@spbstu.ru

St.Petersburg, Russia

Sorption materials for indoor environment cleaning from microorganisms The article touches upon the problem of working area air pollution by pathogenic microorganisms. The problem’s solution requires increased efficiency of filtration materials. Using thermally expanded graphite and Cribrol® polymer composite material, we analyzed air purification quality of multifunctional rooms in comparison with traditional activated carbon. The filtration materials properties were studied using a set of analytical methods. The air was pumped through tested materials in a volume of 500–2000 liters with the use of PU-1B sampling device depositing microorganisms on the nutrient medium. We showed that activated graphite and Cribrol® are effective in cleaning the air from bacteria (cell sizes do not exceed 1 micron), as well as larger microorganisms (from 3 microns or more). Activated graphite completely trapped microorganisms in all test variants. The filtration capacity of the new materials turned out to be higher than that of traditional activated carbon, which indicates the prospects for their further research and practical application. 10.34910/MCE.116.8 697.94 air cleaning technology indoor environment environmentally friendly technologies pathogenic microorganisms human habitat thermally expanded graphite activated graphite polymer sorbent composite materials air filter air pollution air qualit https://engstroy.spbstu.ru/article/2022.116.8/

RAR RUS 11609-11609 Semnan University Kachooee Ali ali.kachooee@semnan.ac.ir An improved lateral restrained local fuse used in concentric braces The present paper continues a series of the authors’ studies on improving conventional concentrically braced frames (CBFs). In previous works, the authors equipped a CBF with a restrained local fuse to improve its behavior, thus introducing local fuse–auxiliary element concentric braces (LF-AECBs). The mechanism of LF-AECBs with a restricted fuse in the length increased the ductility and energy dissipation capacity of the bracing system by limiting the overall buckling locally to the compressive zone. However, further numerical studies suggested that due to early buckling, now local, the restrained local fuse could not be exploited until the failure. Therefore, this study introduces an improved local fuse–auxiliary element concentric brace (ILF-AECB) to fix the issue. Numerical studies are also done to determine the optimal shape of ILF-AECBs in order to obtain maximum energy dissipation capacity and ductility under cyclic loading. In this article, the results of experimental and numerical studies show that ILF-AECBs with a new formulation delaying the fuse buckling completely succeed in using the full capacity of the local fuse for energy dissipation and ductility. Moreover, the analytical study shows that the frame equipped with ILF-AECB offered much better performance in terms of energy dissipation and reduction of the input demand to the structural elements compared to the similar CBFs. 10.34910/MCE.116.9 624 local fuse concentric bracing ductility capacity energy absorption capacity load bearing capacity steel structures https://engstroy.spbstu.ru/article/2022.116.9/

RAR RUS 11610-11610 0000-0003-2533-9732 National Research Moscow State Civil Engineering University Samarin Oleg samarin-oleg@mail.ru Thermal mode of a room with integrated regulation of microclimate systems An air-conditioned room with automatic regulation of its microclimate systems using complex control algorithms is one of the most complex objects for calculating non-stationary thermal regime, so this mode is still insufficiently studied. At the same time, such facilities are typical for providing internal weather parameters in civil buildings. In this paper, we consider a simplified mathematical formulation and solution to the problem of changing the temperature of internal air in a room equipped with a back-ground supply ventilation system and automated local cooling systems under variable thermal effects. The main equations connecting the most important components of the heat flow in the room are analyzed, given we neglect the heat accumulation of the array of fences in the first approximation. The dependence on time for the deviation of the room air temperature from the setpoint and the expression for the moment of time at which the maximum temperature deviation is observed, when the heat flow changes abruptly and the equipment of local cooling systems is regulated according to the integral law are presented. Calculations were made to confirm the obtained analytical solution using a finite-difference approximation of the differential equations of heat balance and heat transfer, as well as by comparing the solution obtained by the author earlier, taking into account the spread of the temperature wave in fences, on the example of one of the currently existing residential buildings in the climatic conditions of Moscow. It is noted that the estimated value of the largest temperature deviation from the setpoint (dynamic control error) and the time for this deviation in the considered problem statement do not depend on the transmission coefficient of the regulator. The obtained relations are proposed to be used for an approximate assessment of the non-stationary thermal regime of an air-conditioned room served by local cooling systems controlled by the integral law, as well as for determining the required parameters of the regulator, including using multivariate calculations with changes in the parameters of the problem. 10.34910/MCE.116.10 697.1:699.86 microclimate temperature heat balance heat gain regulation integral algorithm transmission coeffi-cient civil engineering building construction industry https://engstroy.spbstu.ru/article/2022.116.10/

RAR RUS 11611-11611 55396780000 0000-0002-9832-5895 Housing and Building National Research Center Khater Hesham Moustafa hkhater4@gmail.com

Cairo, Egypt

0000-0002-8272-4349 Housing and Building National Research Center El Nagar Abdeen abdeenelnagar@yahoo.com

Cairo, Egypt

0000-0003-4186-9135 Housing and Building National Research Center Ezzat Mohamed topaz75@gmail.com

Cairo, Egypt

Processing, characterization and hardening mechanism of one-part geopolymer cement Sustainable development of technologies for the industrial waste utilization for building construction areas are given considerable worldwide attention due to their advantages in reduction of greenhouse gases compared to Portland cement as well as conservation of raw materials resources used in cement production. Therefore, geopolymer materials are introduced, not only for the environmental issue, but also because they can reduce carbon dioxide emission caused by Ordinary Portland Cement (OPC) by 80% to 90% in building construction. In this paper, we aim to produce an eco-friendly one-part geopolymer cement with low carbon dioxide emission as an alternative for traditional cements, as well as to conserve the natural resources. The current work focuses on the utilization of industrial wastes rather than natural raw materials with the just-add-water technique for pre-prepared one-part geopolymer cement, which can be applied in various building industries. In the current paper, different types of activators with various ratios and varying firing temperatures from 500 up to 1000°C are studied. The analysis showed that firing of nix at 800°C using 10 and 20% potassium carbonate results in better mechanical strength reaching 550 and 650 Kg/cm2 after 28 days of hardening. 10.34910/MCE.116.11 691.335 mechanical properties smart materials multifunctional composites engineering properties microstruc-ture imaging https://engstroy.spbstu.ru/article/2022.116.11/

RAR RUS 11612-11612 57777329600 0000-0002-4107-2452 Belarusian-Russian University Maskalkova Yuliya julia43@tut.by

Mogilev, Belarus

0000-0001-8854-5408 Belarusian-Russian University Rzhevutskaya Valeryia valeriarzhevuckaya@gmail.com

Mogilev, Belarus

Size effect of cube specimen on strength of expanded clay fiber-reinforced concrete The object of research is expanded clay concrete reinforced with polymer fiber made of polypropylene. Dispersed reinforcement with polymer fibers is one of the priority directions for modifying lightweight concrete, in particular, expanded clay concrete. The article presents the influence of the binary variability of the key factor (edge size of 100 and 150 mm of cube-shaped specimens) on the values of the compressive cube strength of expanded clay fiber-reinforced concrete. Methods. The article presents the experimental studies of the influence of the reinforcing polypropylene fibers content (1.5 % by cement weight) and edge size of cubes (100 mm or 150 mm) on the compressive cube strength of expanded clay fiber-reinforced concrete. Results. Even distribution of fiber throughout the volume provides the effect of crack stopping, regardless of the fiber and concrete type. However, this effect does not appear at small volumes of concrete (in cubes with dimensions of 100×100×100 mm). The empirical data allowed us to state that tests on 100 mm edge cube specimens may produce incorrect values of compressive cube strength. Therefore, it is recommended to test cubes with an edge of 150 mm or more. Conclusions. The results of testing cubes with an edge of 150 mm and 100 mm of lightweight fiber-reinforced concrete demonstrate fundamentally different effects, and testing cubes with an edge size of 100 mm does not guarantee obtaining correct results. 10.34910/MCE.116.12 691.328.43 lightweight concrete expanded clay concrete fiber reinforced concrete fibers polypropylene fibers compressive strength reference specimens cube size size effect https://engstroy.spbstu.ru/article/2022.116.12/

RAR RUS 11613-11613 Samarkand State University Khalmuradov Rustam rustami@list.ru

Samarkand, Uzbekistan

6506121240 0000-0001-8994-9738 Samarkand State University Khudoynazarov Khayrulla khayrullakhudoynazarov@gmail.com

Samarkand, Uzbekistan

Samarkand State University Nishanov Utkir utkirn1978@mail.ru

Samarkand, Uzbekistan

Elastic-plastic deformation of a round plate reinforced with stiffeners The present paper studies the stress-strain state of a round reinforced with stiffeners plate of elastic-plastic material carried out of a refined theory of the type by S.P. Timoshenko It is believed that plate vibrations are excited by a pulsed load. The relationship between displacement and deformation is assumed to be geometrically non-linear. The plate consists of sheathing and rib reinforcement of a quadrangular cross section. The lining materials of the reinforcing ribs are considered identical and obeying Hooke's law. The cross sections of the ribs are constant and are independent of the radial coordinate. The height of the ribs and their locations are set using a single column function. The number of methods of finite differences the solution to the problem. In this case, deformations, forces, moments, and transverse forces are determined at the centers of the grid elements, and displacement and rotation angles are determined at the grid nodes. Given the location of the ribs, the deflection of the central point and the force calculated, depend on the radial co-ordinate and time. Particularly, it was found that the smallest deflection of the central point is achieved when the rib is located in the middle of the radius of the plate; the location of the ribs near the edge of the plate can lead to a decrease in the load-bearing capacity of the structure compared to an un-reinforced plate. 10.34910/MCE.116.13 624.044 elastoplasticity tensor deformation nonlinear vibrations finite deformation nonlinear equation reinforce plate https://engstroy.spbstu.ru/article/2022.116.13/

RAR RUS 11614-11614 0000-0002-4577-8794 Petersburg State Transport University Belash Tatiana belashta@mail.ru “B.E. Vedeneev VNIIG”, JSC Ivanova Tatyana IvanovaTV@vniig.ru

21, Gzhatskaya St., Saint Petersburg, Russia, 195220

0000-0002-2468-3382 “Vedeneev VNIIG”, JSC Ivashincov Dmitry vniig@vniig.ru

St. Petersburg, Russia

Additional measures protecting buildings from climatic influences The Russian territory is characterised by a great variety of different climatic zones with complex weather conditions. There are a large number of people living in these areas. New towns and cities are being built. Ensuring comfortable conditions for people to live and stay in the buildings of various purposes is of great importance for the implementation of social programmes adopted by the Russian government for the near future. Construction practice has developed a certain approach to the materials and structures that protect buildings from the effects of various climatic factors such as extremely high or low temperatures. However, the dramatic climate change that has been taking place on our planet in recent decades has led to additional research and the search for new structural and architectural solutions. This article presents the results of pre-design and construction solutions for public buildings in hot and harsh climates. Different materials for building envelopes are considered and thermal calculations are carried out. The ETFE membrane system is shown to be a versatile material that can be recommended for different climate zones. Particular attention is paid to additional structural measures such as the introduction of special canopies or enclosed spaces in the form of domed structures, which add a certain architectural expression to both the individual building and the group of buildings as a whole. 10.34910/MCE.116.14 699.8 climatic influences negative and positive temperatures ETFE system dome canopy https://engstroy.spbstu.ru/article/2022.116.14/

RAR RUS 11615-11615 57191249816 0000-0002-8080-9808 Ogarev Mordovia State University Rodin Alexander al_rodin@mail.ru https://orcid.org/0000-0002-2560-0948 Ogarev Mordovia State University Ermakov Anatolij anatoly.ermakov97@mail.ru

Saransk, Respublika Mordoviya, Russia

7801669853 0000-0002-3413-247X National Research Mordovia State University Kyashkin Vladimir kyashkin@mail.ru

Saransk, Republic of Mordovia, Russia

0000-0002-4709-4847 National Research Mordovia State University Rodina Natalya rodina.ng@list.ru

Saransk, Republic of Mordovia, Russia

56662851300 0000-0001-8407-8144 Ogarev Mordovia State University Erofeev Vladimir al_rodin@mail.ru Porous glass ceramics from siliceous rocks with high operating temperature Porous glass-ceramic materials although light weighted have relatively high strength, low thermal and sound conductivity, high corrosion resistance, and are non-combustible, etc. They can be obtained from siliceous rocks, the reserves of which are huge. The article considers the obtaining of porous glass ceramic materials with an operating temperature exceeding 900 °C. The materials are obtained from siliceous rocks, Na2CO3, Al2O3 and KCl. Mechanochemical activation of raw materials was carried out in a planetary ball mill. The resulting charge mixture was annealed at a temperature of 850 °C. Experimental results were obtained by using X-ray diffraction (XRD) and thermal (TA) analysis, scanning electron microscopy (SEM), X-ray microtomography (Micro-CT). Physical-mechanical, thermophysical properties and chemical stability of obtained materials were examined. The main crystalline phase of glass ceramics from the calcite-free charge mixture is anorthoclase and quartz. Apart from that samples with calcite charge mixture contain wollastonite and devitrite. The increased content of Al2O3 in the charge mixture displays nepheline in glass ceramics. Calcite in the charge mixture has a significant effect on the microstructure of porous glass ceramics. The number of open pores in the material increases from ≈ 5 % to > 50 %. The compressive strength of porous glass-ceramic materials derived from siliceous rocks reaches 5.1 MPa. In terms of strength, they are significantly superior to foam glass. The minimum thermal conductivity of glass ceramics is 0.065 W/(m∙°С) at a sample density of 244 kg/m3. Samples withstand temperature drops by 230 °C. The material has a high chemical stability and can be operated at temperatures reaching 920 °C inclusively. The obtained materials can be used as thermal insulation of boiler equipment, melting furnaces, etc. 10.34910/MCE.116.15 681.7.035:552.55 glass ceramic construction material thermal insulation siliceous rocks aluminium oxide compressive strength thermal conductivity thermal analysis https://engstroy.spbstu.ru/article/2022.116.15/