75504 2712-8172 Magazine of Civil Engineering 18 8 140 2025
RAR RUS 14001-14001 57194440967 0000-0003-4153-1046 Don State Technical University Nesvetaev Grigory nesgrin@yandex.ru
Rostov-on-Don, Russian Federation
 56056531000 0000-0002-9133-8546 Don State Technical University Chepurnenko Anton anton_chepurnenk@mail.ru
Rostov-on-Don, Russia
 54950122700 0000-0002-5205-1446 Don State Technical University Yazyev Batyr ps62@yandex.ru
Rostov-on-Don, Russia
 57196034514 0000-0002-2341-9811 Don State Technical University Koryanova Yulia koryanova.yi@mail.ru
Rostov-on-Don, Russian Federation
 Modulus of elasticity of concrete at an early age Introduction. The assessment of the risk of early crack formation during hardening of massive monolithic reinforced concrete structures due to temperature gradients predetermines the relevance of studies aimed at increasing the reliability of methods for calculating temperature fields and stresses. When developing technological regulations for concreting, modeling methods are used to assess the risk of early crack formation, the implementation of which requires equations for changing the strength and deformation properties of concrete over time. Highly mobile and self-compacting concrete mixtures with modifiers, which are widely used in concreting the above structures, predetermine the relevance of clarifying known and identifying new patterns of change in the properties of concrete in the early period of hardening, in particular, obtaining equations for changing the E-modulus from prescription factors and temperature conditions. Purpose of the study: obtaining equations for changes in the early and subsequent periods of hardening of the E-modulus of concrete from highly mobile and self-compacting concrete mixtures depending on the prescription factors and temperature conditions during hardening. Methods. Analysis of known approaches to assessing changes in the E-modulus of concrete over time. Modeling using a three-component structural model "matrix – contact zone – aggregate." Experimental studies of the E-modulus depending on the compressive strength limit in the early and subsequent hardening periods of concrete from highly mobile and self-compacting concrete mixtures. Results: Equations are proposed that describe the change in time of the E-modulus of concretes from highly mobile and self-compacting concrete mixtures depending on the compressive strength limit, taking into account the maturity index. The possibility of using the equation EN 1992-1-1 for the change in E-modulus from compressive strength limit for the specified concretes is shown. 10.34910/MCE.140.1 693.547 E-modulus of concrete compressive strength degree of maturity of concrete massive monolithic reinforced structure https://engstroy.spbstu.ru/article/2025.140.1/
RAR RUS 14002-14002 JSC Research Center of Construction, Research Institute of Concrete and Reinforced Concrete (NIIZHB) named A.A. Gvozdev Arleninov Petr arleninoff@gmail.com
Moscow, Russian Federation
 High-strength concrete behavior in post-limit conditions The objects of study were specimens of various shapes and aspect ratios made of high-strength modified concrete B90–B100 with a modified elastic modulus of 55,000 MPa. This modulus significantly exceeds the normative values specified in the building code SP 63.13330 when the concrete is loaded beyond its ultimate state. The need for this study stems from insufficient research on the deformation characteristics of high-strength concretes in extreme states (after reaching the ultimate load – with or without subsequent unloading), as well as the inapplicability of classical microcracking theories (Berg, Winter) to describe their behavior, which requires the development of new evaluation methods. Since high-strength concretes fail brittly, the research methods included two approaches to loading specimens – loading by stresses (standard method) and additionally by deformations up to the peak failure load with subsequent unloading and holding (from 1 hour to 8 days); the elastic modulus was determined according to GOST 24452 before and after loading, while microcrack development was monitored using ultrasonic testing methods (through-transmission and surface sounding). Based on the research results, it was established that during short-term holding (1 hour), the elastic modulus increased by 40–71 % (reaching 73,602–101,192 MPa) – this is explained by crack closure during specimen compression and the inertia of the stress relaxation process, while strength decreased by 20 %. After holding ≥1 day, the elastic modulus (49,684–57,683 MPa) and strength approached the initial values (±6 %), despite visible damage to specimens after initial peak load attainment. At the same time, the ultrasonic wave travel time and Poisson’s ratio (0.21–0.26) remained practically unchanged up to 90 % of the failure load, which does not correspond to classical microcracking development models. The main conclusions of the work: high-strength concretes retain nearly linear deformation behavior even after reaching the ultimate state. These results cast doubt on existing theoretical models describing crack formation processes and emphasize the importance of accounting for stress relaxation in structural assessments, as well as the necessity for comprehensive research on high-strength concretes. 10.34910/MCE.140.2 624.044.2 elastic modulus limit state descending branch high-strength concrete microcracks https://engstroy.spbstu.ru/article/2025.140.2/
RAR RUS 14003-14003 0000-0002-2262-7424 Federal Technological University of Parana Ferreira Elizamary Otto elizamaryotto@gmail.com
Parana, Brazil
 0000-0003-2168-4301 Federal Technological University of Parana Maia Alessandra Tourinho alessandra.tourinho@gmail.com
Parana, Brazil
 0000-0002-9941-999X Federal Technological University of Parana Mazer Wellington wmazer@utfpr.edu.br
Parana, Brazil
 Durability of ultra-high-performance concrete with silica fume and rice husk ash This study analyzed the behavior of Ultra-high performance concrete (UHPC) with two different pozzolans: silica fume and rice husk ash. The use of UHPC as a structural repair material has become common, making it necessary to evaluate its behavior in these situations. The study was conducted by determining compressive strength, assessing permeability and porosity, and assessing its behavior against sulfate attack and exposure to high temperatures. The compressive strength of the concretes was greater than 130 MPa. Regarding porosity and permeability, the concrete composed of silica fume exhibits approximately 20 % lower water absorption than those molded with rice husk ash. Analyzing sulfate attack, the concrete composed of rice husk ash exhibited approximately 50 % lower sulfate penetration than the silica fume composites. The performance of the materials, when subjected to temperatures of 200 and 300 °C, showed reductions in mechanical strength of approximately 26 and 36 %, respectively. At a temperature of 400 °C, the spalling phenomenon occurred. Therefore, there is potential for the use of such a composite due to its high mechanical strength and good performance in relevant characteristics, related to low permeability and high durability. 10.34910/MCE.140.3 691.3 ultra-high performance concrete durability silica fume rice husk ash high temperature https://engstroy.spbstu.ru/article/2025.140.3/
RAR RUS 14004-14004 0000-0002-7703-0756 Civil Engineering Department, University of Baghdad Hasan Haider hayder.hasan2001m@coeng.uobaghdad.edu.iq
Baghdad, Iraq
 Civil Engineering Department, University of Baghdad Al-Saidi A’amal dr.aamal.al-saidi@coeng.uobaghdad.edu.iq
Baghdad, Iraq
 Effect of de-sanding (recycling system) process on the piles bearing capacity The technique adopted in this study includes an innovative and unconventional method, which plays an important role in enhancing the bearing capacity of piles, called a recycling system. Full-scale models were conducted on two groups of piles: the first group was constructed without using this system, and the second group was constructed using it. All piles were tested by static load test. 3D finite element in the PLAXIS program was adopted to understand the load-carrying response of piled, several parameters were studied such as the thickness of the filter cake, type of soil, L/D ratio, and separation between the friction and end bearing. The results revealed that using the recycling system significantly increased the pile-bearing capacity, reaching 50 %. The effectiveness of the recycling system in cohesionless soils is more efficient than in cohesive soils. Pile’s bearing capacity improvement ratio reaches 65 and 38 % for sandy and clayey soils, respectively. In addition, the thickness of the filter cake significantly reduces the pile-bearing capacity, which may exceed 40 % if this system is not used. Using the recycling system, the pile bearing capacity was improved by 60–64 % and 85–98 % for friction and end bearing, respectively. 10.34910/MCE.140.4 624 bored pile bentonite finite element bearing capacity recycling system https://engstroy.spbstu.ru/article/2025.140.4/
RAR RUS 14005-14005 0000-0002-8515-8469 Hanoi University of Mining and Geology (HUMG) Nguyen Trong Dung nguyentrongdung@humg.edu.vn
Hanoi, Vietnam
 National Research Moscow State Civil Engineering University Lam Tang lamvantang@gmail.com
Moscow, Russia
 Multiphasic modeling of hydration degree for blended cement pastes by using calorimetry method The evolution of the mechanical properties of concrete depends greatly on the hydration of the component binders such as cement and mineral additives. However, the prediction of the hydration degree of these binders is extremely difficult due to the complex physic-chemical mechanisms at the molecular level. In this article, the author proposes to use a multiphasic model that considers hydration development and chemical interaction between reactions while taking into account temperature and water content effects on reaction kinetics. The main goal of this study is a semi-adiabatic calorimetry test was applied to determine the input parameters by measuring the heat release during hydration. Based on the test results shown the application of three cases of blended cement paste samples is considered to show the efficiency of the model. Overall, thermogravimetric analyses and its derivative are applied to verify the delay effect of pozzolanic reactions on the hydration degree induced by portlandite content in the paste. 10.34910/MCE.140.5 666.97 Multiphasic model hydration degree cement paste mineral additives https://engstroy.spbstu.ru/article/2025.140.5/
RAR RUS 14006-14006 59387781900 0000-0002-5798-3138 University of Kirkuk Almakinachi Wael waelrami@uokirkuk.edu.iq
Kirkuk, Iraq
 57244116300 0000-0002-4198-7505 University of Kirkuk Salahaldin Ali Ihsan ali.ihsan@uokirkuk.edu.iq
Kirkuk, Iraq
 Performance of reactive powder concrete slender columns exposed simultaneously to eccentric load and elevated temperatures The objective of this study is to examine the impact of elevated temperatures on the structural response of slender columns made of reactive powder concrete (RPC) subjected to eccentric axial loads. Nine RPC column specimens were exposed to a temperature at three different levels: 450 °C, 600 °C, and 750 °C, and to three eccentricities: 50 mm, 100 mm, and 150 mm. The columns underwent fire exposure while being subjected to axial loading equal to 60 % of their ultimate capacity. The outcomes of the experimental tests indicate a noticeable lateral displacement of the RPC columns at high temperatures. The results show that at a constant temperature 750 °C, the mid-height lateral buckling for various eccentricities is significantly higher comparing 50 mm with 100 mm and 150 mm by 59 % and 81 %, respectively. While this rate becomes 36 % and 35 % for 600 °C. At 750 °C, the lateral mid-height buckling is found to be significantly greater when compared to 450 °C and 600 °C by 106 % and 69 %, respectively (for 50 mm eccentricity). While the ratio becomes 48 % and 46 % (for 100 mm eccentricity), one of the main findings in the research is that a low eccentricity value 50 mm, which has a high load, gives higher buckling for each elevated temperature. The mode of failure regarding the column depended on the eccentricity value where the high eccentric loaded columns showed prolonged ductile behavior, while the least eccentric loaded columns showed a brittle type of failure. 10.34910/MCE.140.6 69 fire eccentric loads RPC buckling of columns uniaxial moment slender columns https://engstroy.spbstu.ru/article/2025.140.6/
RAR RUS 14007-14007 0000-0001-5049-8888 Kutateladze Institute of Thermal Physics Lemanov Vadim lemanov@itp.nsc.ru
Novosibirsk, Russian Federation
 Kutateladze Institute of Thermal Physics Fedorenko Viktor vitya.fedorenko.335@mail.ru
Novosibirsk, Russian Federation
 Kutateladze Institute of Thermal Physics Sharov Konstantin sharov@itp.nsc.ru
Novosibirsk, Russian Federation
 Diverging flow in Y-junctions: laminar, transitional and turbulent This investigation is aimed at determining flow regimes in Y-junctions with flow division. Air velocity and velocity pulsations are measured using a hot-wire anemometer in a wide range of Reynolds numbers Re = 400–6000. A junction with diameter d = 6 mm is chosen as the object of study for the inlet and two outlet channels: a symmetrical arrangement of the outlet channels with an angle of 50 º between them. A long tube with diameter d = 6 mm and length l/d = 333 is connected to the junction inlet. Two techniques of the flow regime diagnostics have been developed. For the inlet channel of the junction, the critical Reynolds number is Re = 2000 (puff-type vortex structures appear for the first time). For two outlet channels, a significant increase in velocity pulsations occurs at lower Reynolds numbers Re = 1640–1660. By analogy with diagnostics of the flow movement in a round tube, the following classification of flow regimes in a junction is proposed: laminar flow at Re < 1640–1660, transitional flow at Re = 1660–2800, and turbulent flow at Re > 3000. The obtained data can be used to clarify the range of data for laminar, transitional, and turbulent flow regimes in round Y-junctions with flow division. 10.34910/MCE.140.7 532.559.3 Y-junctions diverging flow hydraulic resistance laminar-turbulent transition critical Reynolds number velocity fluctuation https://engstroy.spbstu.ru/article/2025.140.7/
RAR RUS 14008-14008 55101174500 0000-0001-8650-2375 Peter the Great St. Petersburg Polytechnic University Sharapov Dmitry sharapov.dm@gmail.com
St. Petersburg, Russian Federation
 B-6662-2019 57204916380 0000-0002-6877-8420 Peter the Great Saint Petersburg Polytechnic University Kozinetc Galina galina4410@yandex.ru
St. Petersburg, Russia
 Peter the Great St. Petersburg Polytechnic University Kozinetc Pavel pavelkozinetc@yandex.ru
St. Petersburg, Russia
 Reliability studies of the frame of the C1 shipping opening This article presents a comprehensive computational study of the metal frame of the caisson gate of the C1 shipping opening, part of the St. Petersburg flood protection system. The relevance of this study stems from the need to ensure the strength, stability, and safe operation of this unique 120-meter-long structure, which supports the segmental caisson gate during its movement from the dry dock to the structure's span. The frame is distinguished by its cantilever structure of variable thickness and reinforced with stiffeners. The aim of the study was to develop an adequate spatial computational model of the frame and caisson gate and analyze their stress-strain state for a stationary position in a dry dock. The study was conducted using the finite element method, taking into account constant static loads, including the structures' own weight and hydrostatic pressure. The paper presents the developed spatial finite element model and describes the adopted boundary conditions and loads. Permissible stresses and deflections are determined. The calculations yielded stress and displacement fields. It was determined that the maximum equivalent stresses in the frame do not exceed permissible values. The maximum frame deflection is also within acceptable limits. An analysis of the dynamic characteristics of the structure was conducted. The natural frequencies of vibration were determined for the caisson gate. A stability analysis was performed, showing that the safety factor for the first positive buckling mode exceeds the minimum required. Based on the obtained results, a conclusion was reached that the calculated stresses and deformations comply with regulatory requirements and provide the necessary safety and stability margins. To monitor the condition of the structure during operation, it is recommended to install vibration sensors at critical points, as well as conduct further research. 10.34910/MCE.140.8 532.517 Caisson gate frame shipping opening C1 Neva Bay dry dock calculated stresses calculated deflections https://engstroy.spbstu.ru/article/2025.140.8/
RAR RUS 14009-14009 0000-0003-2372-6544 Kutateladze Institute of Thermal Physics Nizovtsev Mikhail nizovtsev@itp.nsc.ru
Novosibirsk, Russia
 Kutateladze Institute of Thermal Physics Sterlygov Alexei sterlyagov@itp.nsc.ru
Novosibirsk, Russia
 Determining the temperature of soil under a building with a ventilated basement This work is aimed at computational comparative studies of natural changes in soil temperature and under a building with a ventilated basement in Norilsk. In contrast to conventional projects, it was planned to locate a small part of the building directly on the ground, which could lead to additional thawing of the soil. Laboratory data on soil samples in the thawed and frozen state, taken from boreholes at the construction site, and the results of soil temperature measurements at a depth of about 14 m were used to perform calculations. When forming the boundary conditions of the calculation model on the outer surface of the soil, the radiation balance for the conditions of Norilsk was considered. It was found that the radiation balance from May to August is positive and leads to soil heating, and in the rest, most part of the year, it is negative and causes soil cooling. New results obtained demonstrate that a decrease in the moisture content of the surface soil layers reduces the influence of phase transitions on the thermal-inertial properties of the soil, which leads to an increase in the thickness of the active soil layer (where annual temperature fluctuations are observed), an increase in the depth of thawing in the summer-autumn period, and a decrease in the soil temperature under the active layer. The temperature distributions over the depth of soil under different sections of the building with a ventilated basement and in the immediate vicinity of the building in a long-term operation cycle after completion of its construction were calculated. According to calculation results, the maximum depth of soil thaw under a building with a ventilated basement decreased by 12 % compared to natural conditions, reaching 1.1 m. It is shown that for multi-story buildings with ventilated basements, individual structural elements with insulation can be located directly on the ground surface, and additional thawing of the soil will not occur under them. However, for this case, the absence of additional thawing of soil should be confirmed by a heat engineering calculation taking into account the ratio of surface areas of the ventilated basement and the structural elements located on the ground, as well as the features of their insulation. 10.34910/MCE.140.9 624.139 permafrost soil freezing and thawing soil moisture radiation balance building with ventilated basement calculation model https://engstroy.spbstu.ru/article/2025.140.9/
RAR RUS 14010-14010 0000-0001-8567-5880 Materials Engineering Department, Faculty of Engineering, Mustansiriyah University Abdulrehman Mohammed aljaraah_muhammad@yahoo.com
Baghdad, Iraq
 57201032483 0000-0002-6573-4449 Wasit University Goaiz Hussam hussam@uowasit.edu.iq
El'-Kut, Iraq
 Materials Engineering Department, Faculty of Engineering, Mustansiriyah University Salman Ali ali.eng2017@uomustansiriyah.edu.iq
Baghdad, Iraq
 National Center for construction laboratories Motair Mohammed mqmr2020@gmail.com
Baghdad, Iraq
 The durability of white cement by using additives White cement mortar suffers from the appearance of cracks when it is used in the facades of buildings, and these cracks affect its durability and shelf life. Therefore, three additives were suggested to be used with white cement mortar to reduce shrinkage, taking into consideration that they do not negatively affect other cement properties. A type of water-soluble polymer, Polyvinylpyrrolidone (PVP), as well as two types of steel fibers (hooked fibers and straight fibers) and they were all used in proportions 0 %, 1 %, 2 %, and 3 % of the weight of cement. A set of physical and mechanical tests were carried out in addition to dry shrinkage test such as setting time, compressive strength, flexural strength, and water absorption. It was found through these tests that all the additives reduced the dry shrinkage and the best results were obtained when using steel fibers with hooked ends by 3 % where the dry shrinkage was decreased by 75 %. The same type of fiber gave the highest flexural strength, with an increase of 16 % by using the same ratio. As for the use of 1 % straight steel fibers, it achieved the highest value in the compressive strength test, with an increase of 5 %. As for PVP, it reduced the water absorption by 6 % when it was used by 3 %. 10.34910/MCE.140.10 Durability dry shrinkage white cement steel fiber PVP https://engstroy.spbstu.ru/article/2025.140.10/