AlfaBuild

RAR RUS 2001-2001 0000-0003-1844-2782 Moscow Power Engineering Institute Petrenko Valeriia Fedorovna petrenko.valeri82@gmail.com

Moscow, Russian Federation

The natural frequency of a two-span truss The object of the research is a statically definable truss with two spans and a diamond-shaped lattice. One of the supports is a fixed hinge. The other two are movable. The dependence of the first natural vibration frequency of the truss on its size, mass, and also the number of panels is in analytical form. Methods. The rigidity of a structure with masses concentrated in its nodes is determined by the Maxwell-Mohr formula. The lower analytical estimate of the first frequency is calculated using the Dunkerley formula. Results. The generalization of a series of private solutions for trusses with a sequentially increasing number of panels is made by the induction method. The general terms of the sequence of coefficients are determined from the solution of linear homogeneous recurrent equations. All transformations, including finding the forces in the bars by cutting nodes, are performed in the Maple computer mathematics system. To check the solution, the entire frequency spectrum, including the lowest frequency, is in numerical form. Comparison of the analytical solution with the numerical one shows that the accuracy of the analytical estimate from below is quite high and increases with the number of panels. 10.57728/ALF.20.1 69 Truss Maple Evaluation of natural vibrations Natural vibration frequency Two-span truss The rigidity of the supports https://alfabuild.spbstu.ru/article/2021.20.1/

REV RUS 2002-2002 56352359500 0000-0002-5156-7352 Volgograd State Technical University Korniyenko Sergey Valeryevich svkorn2009@yandex.ru

Volgograd, Russian Federation

Advantages, limitations and current trends in green roofs development. A review The green roof systems (GRS) seek to meet the environment and energy efficiency requirements in buildings, where inadequate performance is provided by the conventional roof systems. Some types of green roof have been commercially launched, but challenges, such as high initial cost, complex maintenance, and application limitations, prevent their widespread use. Most of these challenges can be overcome, but no GRS are likely to overcome all of them at once. This research reviews the advantages and disadvantages of green roofs and discusses the challenges associated with their utilization within buildings. The main consumer properties of green roofs have been systematized. The research makes the capabilities and limitations of the different GRS clearer for both architects and users, and discusses the challenges and promises facing developers and designers. 10.57728/ALF.20.2 69 Green roof Environment Vegetation Urban heat island Heating Cooling Energy efficiency Sustainability Biopositivity https://alfabuild.spbstu.ru/article/2021.20.2/ 2002-A.pdf

RAR RUS 2003-2003 R-6085-2016 57196054199 0000-0002-0840-6828 Peter the Great St.Petersburg Polytechnic University Radaev Anton Evgenevich TW-inc@yandex.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

56434269200 0000-0002-7421-3434 Peter the Great St. Petersburg Polytechnic University Gamayunova Olga Bergeevna gamayunova_os@spbstu.ru 0000-0002-5592-6201 Peter the Great St.Petersburg Polytechnic University Bardina Galina Andreevna

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Optimization of energy efficiency design characteristics for construction projects The organization of construction production determines the high importance of solving problems related to energy efficiency in the development of projects both in the field of construction of new buildings and in the area of reconstruction of existing residential facilities. This circumstance, combined with the limitations of existing scientific developments, determined the practicality of researching to develop tools for determining the characteristics of a constructive solution in the field of energy efficiency of a housing construction object. At the initial stages of the study, a review and comparative analysis of existing scientific developments were carried out, the corresponding vital shortcomings were identified. As part of the intermediate stages of the study, the structure of the procedure has been developed, which involves the sequential formation of analytical models describing the dependence of the value of the specific cost of the thermal insulation material on the importance of the technical characteristics of the material within each individual enclosing structure, followed by the creation and implementation of a fractional-linear optimization model to obtain preliminary (mathematically ideal) values of the technical characteristics of the material, as well as models of integer linear optimization for the formation of the composition of the most preferred samples (variants) of the material. 10.57728/ALF.20.3 69 Residential construction object Enclosing structure Thermal resistance Payback period Optimization model Energy efficiency Thermal insulation material https://alfabuild.spbstu.ru/article/2021.20.3/ 2003-A.pdf

RAR RUS 2004-2004 0000-0003-2031-8131 Azerbaijan University of Architecture and Construction Gasanov Elgiz elgiz-etf@mail.ru

Baku, Azerbaijan

0000-0001-9810-5940 Azerbaijan University of Architecture and Construction Mammadov Ahad ahad.mammadov@azmiu.edu.az

Baku, Azerbaijan

0000-0002-3662-0469 Azerbaijan University of Architecture and Construction Aliyev Hamlet hamlet1188@gmail.com

Baku, Azerbaijan

Deformation sheet piles of coastal protection structures, taking into account the effect of their self-weight The object of research is the design of structures used in hydraulic structures in contact with the soil environment are primarily associated with the mechanical properties of soils. Without this, it is impossible to form the conditions of the contact problem, to raise the question of stresses and deformations arising in structures, and also to determine the regularities of the distribution of reactive pressures. Method. The development of effective engineering methods for calculating dock structures in hydraulic structures, based on real design schemes, most fully reflecting the joint work "structure - foundations" can be solved by the Fuss-Winkler hypothesis. The advantage of this method lies in the fact that by introducing special functions called "functional breakers", proposed by Professor N.M.Gersevanov, made it possible to bring the solution to practical results. Results. The use of this method makes it possible to determine the deformations and forces of the walls of coastal protection structures, dock, chute structures of spillway structures, which are widely used in hydraulic engineering structures, taking into account the effect of their self-weight on lateral loads. 10.57728/ALF.20.4 69 Deformation Winkler-Fuss method Self-weight Soil conditions Hydrostatic water pressure https://alfabuild.spbstu.ru/article/2021.20.4/

RAR RUS 2005-2005 AAA-7620-2022 57190860068 0000-0001-9245-2511 Ogarev Mordovia State University Dergunova Anna Vasilevna anna19811981@mail.ru

Saransk, Russian Federation

A-7827-2017 56662851300 0000-0001-8407-8144 Ogarev Mordovia State University Erofeev Vladimir Trofimovich yerofeevvt@mail.ru

Saransk, Russian Federation

Economic, environmental, and social benefits of green building The object of research is the problem of the introduction of green construction. The main economic, social and ecological advantages of green construction are given. Brief explanations and justification of the need for the construction of green buildings are given. Method. The basis for the development of a calculation formula for determining the comparative economic efficiency of green construction is based on the method of comparing the total reduced costs, taking into account the factor of their different times and areas of application. At the same time, costs are taken into account in the field of creation and supply of environmentally friendly building materials and structures, in the field of construction of energy-efficient construction facilities and in the field of operation of buildings and structures. Results. The conducted research allows us to conclude that the additional costs for the construction of a green building pay off during the first years of operation of the building, bringing considerable profit in the future. And for eco-resistant buildings, plus to the specified economic effect, it is necessary to add a significant improvement in the physiological and social aspects of living in such buildings. 10.57728/ALF.20.5 69 Green building Cost savings Global warming Energy efficiency Environmental friendliness https://alfabuild.spbstu.ru/article/2021.20.5/

RAR RUS 2006-2006 AAB-5421-2022 57195312706 0000-0001-8891-8120 Penza State University Gavrilov Mihail Aleksandrovich gavrilov79@inbox.ru

40, Krasnaya Street, Penza, 440026, Russian Federation

A-7827-2017 56662851300 0000-0001-8407-8144 Ogarev Mordovia State University Erofeev Vladimir Trofimovich yerofeevvt@mail.ru

Saransk, Russian Federation

AAB-4881-2022 57214232767 0000-0001-7976-9792 Ogarev Mordovia State University Afonin Viktor Vasilyevich vvafonin53@yandex.ru

Saransk, Russian Federation

Assessment of the durability of epoxy composites in a model environment mycelial fungi The object of research is to determine the degree of durability of polymer epoxy-based composite samples under the influence of mycellial fungi metabolitic products. Such products have high degree of destructive activity as well as ability to adapt to materials with various chemical compositions. Asbestos-based fillers were used to create durable epoxy-basedpolymer composites. To characterize microbiotic durability rating the following methods were used. Experimental data were used to construct a mathematical model of the durability of epoxy composites. The regression equation is used as an objective function to find the global maximum of the resistance coefficient of the studied composites. The results for composites with fillers are compared with a control sample without filler. The composition of model environment to influence epoxy-based polymer compositions was determined. The realization of planning matrix provides mathematical of durability for modified epoxy-based polymer compositions. The specific effects of micromycete fungi were determined depending on the content and type of filler. Asbestos-based fillers of various nature derived from industrial waste were shown to be effective in creating durable epoxy-based polymer compositions. 10.57728/ALF.20.6 69 Durability coefficient Epoxy composites Planning matrix Regression equation Objective function Global optimization https://alfabuild.spbstu.ru/article/2021.20.6/

RAR RUS 2007-2007 A-7827-2017 56662851300 0000-0001-8407-8144 Ogarev Mordovia State University Erofeev Vladimir Trofimovich yerofeevvt@mail.ru

Saransk, Russian Federation

0000-0003-0588-6341 Ogarev Mordovia State University Ivlev Viktor Ivanovich ivlevvi2010@mail.ru

Saransk, Russian Federation

0000-0001-7573-2546 Ogarev Mordovia State University Yudin Vyacheslav Alexandrovich uva201@mail.ru

Saransk, Russian Federation

Ogarev Mordovia State University Myshkin Anton Vladimirovich yerofeevvt@mail.ru

Saransk, Russian Federation

Ogarev Mordovia State University Sigachev Alexandr Fedorovich siaf@mail.ru

Saransk, Russian Federation

ABE-1858-2021 57208300172 0000-0003-0031-7270 Peter the Great St. Petersburg Polytechnic University Kotliarskaia Irina Leonidovna iravassilek@mail.ru

St. Petersburg, Russian Federation

Ogarev Mordovia State University Beglov Vladimir Ivanovich

Saransk, Russian Federation

Mechanical hysteresis in cured polyester acrylate resin MGF-9 The object of research is the deformation characteristics of the hardened polyester-acrylate resin grade MGF-9, which is a promising basis for polymer composite materials. A curing system consisting of PKOH-2 cyclohexanone peroxide and OK-1 cobalt octoate was used. Method. The study was carried out by the method of a physical experiment using the Shimadzu Autograph AG-X Series universal testing machine in various loading and unloading modes, including a cyclic mode for taking a tension-compression diagram. The mechanical hysteresis was studied when the samples were deformed at a rate of 1 to 10 mm/min. Hysteresis losses were determined depending on the number of cycles, stress, and strain rate. The main factor determining the number of losses is the maximum deformation in the cycle. Results. The complex nature of the change in the effective modulus was revealed, which indicates a change in the molecular structure of the material during deformation and, accordingly, a change in the molecular mechanism of this process. The greatest changes occur in the first cycle, so the preliminary deformation leads to the stabilization of the state of the material. Deformation of the cured resin to varying degrees and in different modes leads to significant changes in its properties due to changes in its molecular structure. The dependences of the effective (conditional) modulus on the degree of deformation during the loading of the sample and its unloading differ significantly. The obtained results on physical and mechanical properties are suitable for use in the design of products for various purposes. 10.57728/ALF.20.7 69 Polyester acrylate resin Composite material Deformation Mechanical hysteresis Strength properties Elastic-plastic properties https://alfabuild.spbstu.ru/article/2021.20.7/ 2007_1(1).pdf

RAR RUS 2008-2008 A-7827-2017 56662851300 0000-0001-8407-8144 Ogarev Mordovia State University Erofeev Vladimir Trofimovich yerofeevvt@mail.ru

Saransk, Russian Federation

0000-0003-0588-6341 Ogarev Mordovia State University Ivlev Viktor Ivanovich ivlevvi2010@mail.ru

Saransk, Russian Federation

0000-0001-7573-2546 Ogarev Mordovia State University Yudin Vyacheslav Alexandrovich uva201@mail.ru

Saransk, Russian Federation

Ogarev Mordovia State University Myshkin Anton Vladimirovich yerofeevvt@mail.ru

Saransk, Russian Federation

Ogarev Mordovia State University Sigachev Alexandr Fedorovich siaf@mail.ru

Saransk, Russian Federation

ABE-1858-2021 57208300172 0000-0003-0031-7270 Peter the Great St. Petersburg Polytechnic University Kotliarskaia Irina Leonidovna iravassilek@mail.ru

St. Petersburg, Russian Federation

Ogarev Mordovia State University Beglov Vladimir Ivanovich

Saransk, Russian Federation

Deformation of composite material based on polyester acrylate resin The object of research is a composite material obtained based on MGF-9 polyester-acrylate resin with quartz sand as a filler. Samples were prepared using a curing system consisting of PKOH-2 cyclohexanone peroxide and OK-1 cobalt octoate. Method. Physical experiment. The compressive strain was performed on a Shimadzu Autograph AG-X universal testing machine. To process the results, differential methods were used: calculation of the effective modulus and the rate of change of mechanical parameters. According to the obtained graphic dependences, an analysis of the change in mechanical parameters was carried out, a comparison was made with samples not filled with quartz sand. Results. The nature of the change in the effective modulus depending on the degree of deformation and the magnitude of mechanical stress during deformation of the composite and pure resin differ significantly, which indicates the difference in the molecular processes occurring in them. It is shown that the hysteresis loss in the composite is usually less than in the resin without filler. As in unfilled samples of polyester acrylate, the greatest change in the state of the material occurs in the first loading cycle. 10.57728/ALF.20.8 69 Polyester acrylate resin Composite material Deformation Hysteresis Mechanical parameters https://alfabuild.spbstu.ru/article/2021.20.8/ 2008.pdf

RAR RUS 2009-2009 57220160973 0000-0001-6095-5667 Ogarev Mordovia State University Zotkina Marina Mihailovna zotkina.mm@yandex.ru

Saransk, Russian Federation

A-7827-2017 56662851300 0000-0001-8407-8144 Ogarev Mordovia State University Erofeev Vladimir Trofimovich yerofeevvt@mail.ru

Saransk, Russian Federation

Resistance of decorative epoxy composites to sea climate The object of research is composite materials based on an epoxy binder with various pigments. The purpose of the research is to substantiate the proposed methodology for analyzing the colour change of protective coatings and to evaluate the decorative properties of epoxy composites used in marine climate conditions. Method. The studied composites were aged in natural and climatic conditions in the coastal strip of the Black Sea of the city of Gelendzhik (Russia) in an open area and under a canopy. Samples were scanned at control points. The resulting images were processed in a software package based on the use of the RGB colometric system, using the compiled C# programming language on the platform .NET. Results. As a result of the tests carried out, the dependences of changes in the RGB codes of composites were established. The compositions most resistant to colour degradation were determined, which are affected by aggressive factors, such as high humidity, ultraviolet radiation, salt fog, precipitation and seasonal temperature fluctuations. 10.34910/ALF.20.9 69 Decorative properties Color RGB code Epoxy compounds Pigment Marine climate https://alfabuild.spbstu.ru/article/2021.20.9/

REV RUS 2010-2010 57274359600 0000-0002-6008-3712 National Heritage Foundation Zivaljevic-Luxor Natasa luxornatasa@gmail.com

Belgrade, Serbia

7004191121 0000-0003-0473-0302 Brandenburg University of Technology Pasternak Hartmut h.pasternak@web.de

Cottbus, Germany

Large-span structures for purposes of heritage sites The object of research is large-span structures for the presentation of archaeological sites in situ - construction of roofs, shelters, and bridges with the aim to provide support in the decision-making process for architects and engineers. Method. We examined existing practices and analyzed their engineering classification looking for a pattern in their application. Contemporary engineering structures at built heritage sites create a sharp contrast between old and new. A presentation of cultural heritage in situ requires an understanding of heritage theory and internationally accepted doctrine, which exceeds common engineering education. Nevertheless, the application of large-span structures, which often takes advantage of state-of-art construction technologies nowadays, is also an aesthetical statement that affects the appearance of the site. Therefore, we gave an overview of the theoretical background of aesthetical issues and the overall ethics of the decision-making process in such sensitive cases. Results. Within the framework of heritage presentation, engineering and architectural issues, and selected case studies, we concluded in favor of the application of large-span structures under certain conditions. 10.57728/ALF.20.10 69 Archaeological site Built heritage Roof Shelter Bridge Aesthetics Heritage Presentation Decision-making Engineering Construction https://alfabuild.spbstu.ru/article/2021.20.10/