75504 2712-8172 Magazine of Civil Engineering 2 118 2023
RAR RUS 11801-11801 0000-0002-4966-9894 Chitkara University Singh Jagdeep jagdeep.singh71717@gmail.com
Rajpura, India
 6701385641 0000-0003-0128-6306 Thapar Institute of Engineering & Technology (Deemed to be University) Siddique Rafat siddique_66@yahoo.com
Patiala, India
 Performance of waste foundry sand concrete in sulfate environment Waste foundry sand is generated by the metal casting industry and has great potential to be used as a construction material. Nearly 70 % of the waste foundry generated is disposed of as a landfill which poses a threat to the surrounding environment. The negative impact of landfill disposal of waste foundry sand on the environment has invited the intentions of research faculty. In this research work, the impact of waste foundry sand as sand replacement on the properties of concrete cured in water as well as sulfate solution were explored. Test results indicate that the compressive strength of concrete cured in sulfate solution decreases with the use of waste foundry sand as partial substitution of natural sand. However, a chloride ion penetration resistance of concrete hikes on the accumulation of waste foundry sand. Up to 56 days, a concrete mixture made up of 15 % waste foundry sand showed optimum strength properties. Ultrasonic pulse velocities through concrete mixtures cured either in water or sulfate solution were almost identical. Energy dispersive spectroscopy analysis showed traces of sulfur in concrete mixtures cured in a sulfate solution. 10.34910/MCE.118.1 691.5 concrete curing compressive strength durability microstructure scanning electron microscopy x-ray diffraction https://engstroy.spbstu.ru/article/2023.118.1/
RAR RUS 11802-11802 57218421564 0000-0003-2238-196X Hanoi University of Civil Engineering Nguyen Ngoc Lam lamnn@huce.edu.vn
Hanoi, Vietnam
 15749118200 0000-0002-3561-9781 National Institute of Applied Sciences of Lyon Georgin Jean Francois jean-francois.georgin@insa-lyon.fr
Villeurbanne, France
 35737585800 0000-0001-9637-7125 National Institute of Applied Sciences of Lyon Prud'Homme Elodie elodie.prudhomme@insa-lyon.fr
Villeurbanne, France
 Long-term strength and porosity of mortars based on ettringite binder Ettringite binder is widely used in mortars for technical applications such as patching mortars, self-leveling screeds, repair mortars thanks to their fast hardening ability and high early strength. However, depending on the amount and types of raw materials used in the composition, the properties of these types of binder have different behaviors at early-age and at long term. In this work, the influence of the nature and dosage of calcium sulfate in ettringite binder on the long-term strength of mortar in different curing conditions was determined. The results showed that the increase of calcium sulfate content in ettringite binder from 10–25 % improves the strength of mortars regardless of the calcium sulfate nature. In all curing conditions (endogenous, drying, outdoor), the strength of ettringite mortars with anhydrite is smaller than that of mortars containing hemihydrate. There is no major difference in the porosity of the mortars in different types of curing conditions before 28 days. However, after 28 days the porosity of mortar in drying condition is about 2–3 % higher than that of the mortars in endogenous and outdoor conditions. 10.34910/MCE.118.2 691.31 ettringite durability long-term porosity strength https://engstroy.spbstu.ru/article/2023.118.2/
RAR RUS 11803-11803 0000-0002-0934-549X National Research Mordovia State University Dudynov Sergey dsergey@mail.ru
Saransk, Russia
 Influence of biological additives on the properties of cement systems The object of the research is cement systems, the materials most commonly used in the construction industry. Since people interact with construction materials all the time, they should only contain harmless components; this requirement applies to modifiers as well. The existing liquefiers are obsolete; there is a need for an alternative composition and production technology. The purpose of the research is, first, to theoretically design the structure of an environmentally friendly plasticizing additive for cement systems based on fragments of natural compounds – lipids and carbohydrates. Secondly, to select a non-pathogenic microbial culture capable of synthesizing this product and the conditions for its fermentation. And finally, to study the properties of cement systems containing the synthesized biomodifier. This paper proposes novel modifiers based on fragments of natural compounds. The production process should be based on biological synthesis running through the cellular structures of microorganisms growing in a synthetic nutrient medium. A non-pathogenic microbial culture was ‘tamed’ to synthesize this product. The authors further designed a synthetic nutrient medium and optimized the fermentation parameters. Ten hours after the onset of fermentation, a fat-like substrate is added to the nutrient medium so that Leuconostoc mesenteroides would be able to synthesize the hypothesized modifier. The output is an efficient glycolipid plasticizer. X-ray diffraction analysis, a plastometer, a flow table, a cone, a viscometer, a versatile press, and an ionometer were used in this research to find the parameters of the synthesized bioadditives and cement systems based on them. The bioplasticizer injection was noted to increase the fluidity of cement mixtures by a factor of 3 to 5. The novel modifiers greatly inhibit early cement hydration when dosed at >0.8 wt.%. However, while inhibiting early structuring, these liquefiers strengthen the material in the long term (3+ months). Injecting these biological additives in the mixture at up to 0.8 wt.% produces a material that is 20÷30 % stronger than the additive-free alternative and absorbs less water while being as resistant to frost. As per our hypothesis, the microbial synthesis did in fact produce efficient cement system modifiers for industrial and residential construction that would be subject to no environmental restrictions. 10.34910/MCE.118.3 691.32:579.66 сoncrete cements mixtures additives microbiological synthesis proteins lipids mechanical properties hydration environmental safety https://engstroy.spbstu.ru/article/2023.118.3/
RAR RUS 11804-11804 57196438866 0000-0002-1035-887X Tambov State Technical University Erofeev Alexander AV.Erofeev@yandex.ru
Tambov, Russia
 57194260987 0000-0002-1410-9520 Tambov State Technical University Gorokhov Timofey gorohowt@yandex.ru
Tambov, Russia
 Method for determining the thermal fluctuation constants of the generalized Zhurkov equation Reliable forecasting of the service life of building materials and products allows you to lay down the costs of repair work in a timely manner, which in modern economic realities is undoubtedly an urgent task. This paper presents the results of a study on the development and comparison with existing methods for determining the thermal fluctuation constants of the generalized Zhurkov equation. A new method is proposed for determining the thermal fluctuation constants of the generalized Zhurkov equation. Practical application of the methodology will make it possible to reliably predict the service life of building materials. The main goal is to develop a method for determining the thermal fluctuation constants of the generalized Zhurkov equation, characterized by higher reliability by reducing the number of operations entailing errors, while increasing the number of experiments conducted under identical conditions (increasing the sample when determining durability under constant operating conditions). To achieve this goal, it is necessary to solve a number of tasks: 1) analyze the main provisions of the thermal fluctuation concept; 2) develop a method for determining the thermal fluctuation constants; 3) to conduct a comparative analysis of the obtained results of determining the thermal fluctuation constants. The object of the study is the constants of thermal fluctuation. The subject of the study is a new method for determining thermal fluctuation constants. The main methods of scientific knowledge used in the development of the methodology are hypothetical (the hypothesis of a linear dependence of the change slope of direct temperatures in the coordinates of the logarithm of durability - stress) and experiment (determination of durability of samples under transverse bending under specified operating conditions). A new method was developed for determining the thermal fluctuation constants of the generalized Zhurkov equation. It allows you to determine constants by plotting only one straight line temperature and one control point at a different temperature. Application of the proposed technique allows increasing the number of samples tested in identical conditions while reducing labor costs for experimental research. An increase in the sample leads to an increase in the accuracy and reliability of predicting the service life of building materials. 10.34910/MCE.118.4 691 construction experimental research forecasting performance durability temperature thermal fluctuation https://engstroy.spbstu.ru/article/2023.118.4/
RAR RUS 11805-11805 55644946900 0000-0002-4508-4733 Universitat Politecnica de Valencia Almerich-Chulia Ana analchu@mes.upv.es
Valencia, Spain
 55644567800 0000-0001-8857-3249 Universitat Politecnica de Valencia Martin-Concepcion Pedro pmartin@mes.upv.es
Valencia, Spain
 54994161700 0000-0002-3721-5369 Universitat Jaume I Molines-Cano Jose M molines@uji.es
Castelló, Spain
 57195312827 0000-0001-9262-7916 Universitat Politecnica de Valencia Moreno-Puchalt Jesica jemopuc@mes.upv.es
Valencia, Spain
 Experimental behavior of novel GFRP reinforcing bars under compressive loads Glass fiber-reinforced polymer (GFRP) bars have been used in RC structures due to their high tensile strength capacity and resistance to corrosion in comparison with steel. However, international standards do not recommend their use in RC structure elements subjected to compressive loads. Currently, there is no standard method to determine the compressive characteristics of FRP bars. This article presents a new type of GFRP bars designed specially to support compressive loads: they have additional winding GFRP layers around the longitudinal fibers. An exhaustive experimental study was carried out to obtain compressive properties of the bars: compressive strength, Young’s modulus and stress-strain relation. After post-processing the experimental results of the study, this paper showed compressive strength between 50% and 60% of tensile strength, which allows employing the bars as internal reinforcement in RC structures. Their obtained Young’s modulus is the same in both tensile and compression, which enables the linear stress-strain relation to be extended to the entire range of deformations. This is most advantageous for structural analysis procedures in the linear elastic regime. Finally, based on the experimental results of failure modes, some limitations about the cross-sectional area or the slenderness were proposed for the use as internal reinforcing in RC structures, which helps the researchers in the design procedure for members reinforced with FRP bars. 10.34910/MCE.118.5 624.07 fiber-reinforced polymer glass fiber-reinforced polymer GFRP bars compression test compressive strength slenderness reinforced concrete mechanical properties https://engstroy.spbstu.ru/article/2023.118.5/ 05.pdf
RAR RUS 11806-11806 57212348775 0000-0002-7168-5786 Peoples’ Friendship University of Russia Gebre Tesfaldet tesfaldethg@gmail.com
Moscow, Russia
 https://orcid.org/0000-0003-2493-7255 Peoples' Friendship University of Russia (RUDN University) Galishnikova Vera galishnikova-vv@rudn.ru
Moscow, Russia
 57197822677 0000-0003-3926-8701 Moscow State University of Civil Engineering (National Research University) Lebed Evgeny evglebed@mail.ru
Moscow, Russia
 Peoples' Friendship University of Russia Tupikova Evgeniya emelian-off@yandex.ru
Moscow, Russia
 Modelling of thin-walled members with restrained torsion considering the section properties Various engineering structures include lightweight or thin-walled beam structures that are used in a complex loading situation which includes restrained torsion of closed or open section. The importance of restrained torsion of thin-walled cross-sections is significant as the deformations and stresses caused by torsion affect the behaviour of the structures with open as well as closed section. The aim of this study is to demonstrate and compare different methods used to develop stiffness matrix for the finite element beam calculation of open and closed thin-walled sections with restrained torsion. The beam stiffness matrices are presented and graphically compared in order to choose the most convenient method for advanced structural analysis of thin-walled 3D beams with restrained torsion. The interpolation functions containing hyperbolic and approximate functions are considered, which satisfy the governing differential equation for torsion, with different value of characteristic number of torsion (θ). Comparing both methods, we can conclude that both are similar for small value of θ and this is commonly considered for open thin-walled section as their value of θ is small. The percentage of error between the results obtained by two methods of element stiffness matrix development for torsion with restrained warping is given graphically. Based on this study, numerical examples are considered and compared with results obtained by different finite element software. The examples include restrained and free torsion which are nonuniform and uniform torsion, respectively. 10.34910/MCE.118.6 69.04 thin-walled structures stiffness matrix open section closed section angle of twist uniformed torsion nonuniform warping https://engstroy.spbstu.ru/article/2023.118.6/
RAR RUS 11807-11807 0000-0002-0317-7296 Moscow Aviation Institute Vartanyan arevshadvartanyan@mail.ru
Moscow, Russia
 0000-0003-4928-9960 National University of Architecture and Construction of Armenia Sarukhanyan Arestak sarukhanyan.arestak@mail.ru
Yerevan, Republic of Armenia
 0000-0001-9093-2271 National University of Architecture and Construction of Armenia Veranyan Gevorg g.g.veranyan@mail.ru
Yerevan, Republic of Armenia
 0000-0002-2315-7233 Shushi University of Technology Tokmajyan Hovhannes tokmadzhyan_hv@mail.ru
Yerevan, Republic of Armenia
 Regularity of natural oscillations characteristics change of tall earth dams A preliminary assessment of the strength of earth dams under dynamic loads is one of the most important tasks associated with the design of such massive hydraulic structures. The present study is devoted to predicting the deformation of earth dams under the influence of strong earthquakes, which are possible in the immediate vicinity of the dam location. Recently, a number of large earthquakes have occurred in the world, which led to severe destruction and indicate high seismic risks associated with the potential instability of existing large earth dams. Under intense seismic impacts, the response of the dam depends on various factors, including its geometric dimensions, as well as the type of structure. A number of existing dams, which were designed and built according to the normative rules of their time, do not take into account modern real operating conditions, in particular, potential seismic loads. This article examines the influence of these factors on the stability and strength of earth dams, taking into account the real properties of the soils of the dam body and the base of the bottom of the hydraulic structure in accordance with the new regulatory requirements. On the basis of the proposed mathematical model, verification calculations for the strength and stability of such earth dams located in the seismic zone were carried out. To assess seismic safety of high earth dams built and operating in regions of complex climatic conditions, including frequent earthquakes, the proof of the method choice capable of reliable and valid results in terms of adopted assessment criteria is required. Correct mathematical model choice ensures, on the basis of computations, strength indices of the hydraulic structure under study. In particular, comparison and analysis of calculated date obtained in case of the plane calculation model and spatial model with the field measurements results and spectral analyses of the Sarsang dam accelerograms showed the suggested calculation models provided reliable strength indices results for the earth dams in the operating reservoirs. The use of more complex models of the physical and mechanical properties of the dams’ soil leads to reliable results that are in good agreement with real field tests. 10.34910/MCE.118.7 627.8 dam oscillation period accelerogram strength characteristics of earth dams hydraulic structure https://engstroy.spbstu.ru/article/2023.118.7/
RAR RUS 11808-11808 0000-0003-3715-5180 Department of Civil Engineering, Qazvin Branch, Islamic Azad University Moradi Hamidreza hamidrezamoradi1360@yahoo.com
Qazvin, Iran
 0000-0001-8385-9272 Department of Civil Engineering, Qazvin Branch, Islamic Azad University Hashemi Seyed Amir Hossein hashemi@qiau.ac.ir
Qazvin, Iran
 Neural prediction of mechanical properties of fiber-reinforced lightweight concrete containing silica fume and nano-silica Experimenting to acquire the optimum result for producing a product in a real environment takes a long time and has various costs. Numerical simulations help save time and improve accuracy in implementing numerous complex tests. The present study exploits neural networks in MATLAB to calculate the mechanical properties of fiber-reinforced lightweight concrete under different fractions of silica fume and Nano silica, steel and polypropylene fibers, cement, and scoria. Concrete specimens were constructed under different mix designs and subjected to 7- and 28-day compressive, tensile, flexural, and initial and ultimate water absorption tests. Then, a multilayer perceptron (MLP) was used as the neural network. Furthermore, 70 % of the specimens were utilized as the training data samples, 15 % were exploited as the validation data samples, and the remaining 15 % were employed as the testing data samples. The MLP was trained for seven inputs, one hidden layer, and 20 neurons. The model training, testing, and overall accuracy were 100 %, 97.3 %, and 99.5 %, respectively, indicating the model is efficient and effective. 10.34910/MCE.118.8 624 artificial neural network lightweight concrete mechanical properties steel fibers polypropylene fibers silica fume nanosilica fiber-reinforced concrete https://engstroy.spbstu.ru/article/2023.118.8/
RAR RUS 11809-11809 Kazan State University of Architecture and Engineering Pimenov Sergey 3.14manon@mail.ru
Kazan, Russia
 0000-0001-9999-6925 Kazan State University of Architecture and Engineering Galautdinov Albert galautdinov89@mail.ru
Kazan, Russia
 Heavy-weight concrete with increased early strength Production process rate is the most important thing in industrial engineering of concrete and reinforced concrete products, which heavily depends on duration of concrete handling strength development. One of the methods of processes’ intensification of concrete structure formation is steam treatment. However, destructive processes developing in concrete in some instances during its long steam treatment at the temperatures above 40°C necessitate reducing its duration. This is achieved through the use of methods of further intensification of concrete structure formation processes, one of which is hydromechanical activation of binder. Research results of joint effect of hydromechanical activation of cement binder and following steam treatment on kinetics of heavy-weight concrete strength development are presented in the paper; special aspects of hydration and structure formation of cement stone are studied. We found an increase in strength development rate of heavy-weight concrete during isothermal warming temperature increment. Technological parameters of steam treatment of concrete based on cement binder under hydromechanical activation are determined for preparing В30–В60 grade concretes using components for В25 heavy-weight concrete. Received results are of substantial interest to construction industry and can be used in prefabricated concrete and reinforced concrete technology, which gives the opportunity to reduce energy intensity of production and end product cost. 10.34910/MCE.118.9 691.32 heavy-weight concrete steam treatment hydromechanical activation isothermal warming https://engstroy.spbstu.ru/article/2023.118.9/
RAR RUS 11810-11810 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers Jurayev Doniyor tohir-zs@mail.ru M-6585-2013 6508103761 0000-0002-1196-8004 Peter the Great Saint Petersburg Polytechnic University Vatin Nikolai vatin@mail.ru
Polytechnicheskay, 29
 55586710000 0000-0002-6498-5043 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers Sultanov Takhirjon tz-sultanov@mail.ru
Tashkent, Republic of Uzbekistan
 S-1676-2017 6507460407 0000-0002-8907-7869 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers Mirsaidov Mirziyod theormir@mail.ru
39, Kori Niyoziy St., Tashkent, Uzbekistan, 100000
 Spatial stress-strain state of earth dams The study is devoted to the stress-strain state (SSS) of various earth dams analyzed using a spatial model. The article provides a detailed review of well-known scientific publications on the SSS assessment of dams. In this article, a mathematical model was developed to assess the SSS of earth dams using a spatial model based on the Lagrange variational equation, considering real geometry, properties of the material, and non-homogeneous design features of structures. A technique was developed for solving spatial problems to assess the SSS of earth dams by the finite element method using the program developed by the authors and the ABAQUS software. The adequacy of the mathematical model and the accuracy of the results obtained were verified by solving test problems. The SSS of the Ghissarak (H = 138.5 m), Sokh (H = 87.3 m), and Pachkamar (H = 70.0 m) earth dams under the action of body forces and hydrostatic water pressure was studied. It was established that the greatest displacements were observed on the crest and in the zone of the dam core; an account for nonhomogeneous design features significantly affects the resulting displacement field in the core zone; a spatial deformed state of the structure occurs near the banks; positive stress (not considered in a plane model) arises in a small area in the upper part of the core near the crest, caused by the crest indentation by the lateral surcharge. 10.34910/MCE.118.10 539.3 earth dam plane and spatial models body forces hydrostatic pressure stress-strain state variational equation core indentation https://engstroy.spbstu.ru/article/2023.118.10/
RAR RUS 11811-11811 0000-0003-0198-6679 Almalik Branch, National University of Science and Technology MISiS Eshmatov Bakhtiyor ebkh@mail.ru
Almalik, Uzbekistan
 6506522453 0000-0001-8114-1187 Tashkent Financial Institute Abdikarimov Rustamkhan rabdikarimov@mail.ru
60A, A.Temur street, Tashkent city, 100000
 0000-0001-9340-4474 McGill University Amabili Marco marco.amabili@mcgill.ca
Montreal, Canada
 M-6585-2013 6508103761 0000-0002-1196-8004 Peter the Great Saint Petersburg Polytechnic University Vatin Nikolai vatin@mail.ru
Polytechnicheskay, 29
 Nonlinear vibrations and dynamic stability of viscoelastic anisotropic fiber reinforced plates Fiber-reinforced plastic composites are one of the most widely used composite materials because they balance well between properties and cost. Despite their widespread use in the aviation and automotive industries, there is currently a lack of effective mathematical models for their calculation under various dynamic loads. The research object of this work is an anisotropic viscoelastic fiber-reinforced simply supported rectangular plate. Two dynamic problems are considered: vibrations of the plate under the influence of a uniformly distributed static load; stability of the plate compressed in one direction. Within the Kirchhoff-Love hypothesis framework, a mathematical model was built in a geometrically nonlinear formulation, taking into account the tangential forces of inertia. By the Bubnov-Galerkin method, based on a polynomial approximation of the deflection and displacement, the problem was reduced to solving systems of nonlinear ordinary integro-differential equations. With a weakly singular Koltunov-Rzhanitsyn kernel with variable coefficients, the resulting system was solved by a numerical method based on quadrature formulas. By using experimental studies, considering the directions of the fibers, the values of the rheological parameters of some plastic materials (KAST-V and EDF) were obtained. The plate's dynamical behavior was investigated depending on the plate's geometric parameters, viscoelastic and inhomogeneous material properties. Results show the importance of taking into account the viscoelastic properties of the material when solving dynamic problems of anisotropic reinforced plates made of composite materials. In particular, when studying the problem of dynamic stability of an anisotropic reinforced plate made of KAST-V, the results obtained in elastic and viscoelastic formulations in some cases differ from each other by more than 20 %. 10.34910/MCE.118.11 69.04 nonlinear vibrations dynamic stability viscoelastic anisotropic fiber-reinforced plate integro-differential equations weakly-singular Koltunov-Rzhanitsyn kernel https://engstroy.spbstu.ru/article/2023.118.11/