75504 2712-8172 Magazine of Civil Engineering 5 105 2021 1-169
RAR RUS 10501-10501 6504446571 0000-0001-6981-7420 Jordan University of Science and Technology Al-Rousan Rajai rzalrousan@just.edu.jo
Irbid, Jordan
 The impact of depth on shear behavior of strengthened beams The main aim of this work is to investigate the influence of the beam's depth on the behavior of the externally-strengthened-with-CFRP beams, having shear deficiency. The Nonlinear Finite Element Analysis (NLFEA) has been utilized to construct and validate study models, which had been subjected to load till failure aiming to monitor their performance. Also, the cracking's first appearance, the increase rate of cracking according to loadings, and ductility were all put to observation. The NLFEA results indicated that strengthening the RC beams with externally-bonded CFRP enhanced the beams' shear capacity, in accordance to the study parameters. The strips of CFRP enhanced the beam's ultimate load by 15–19 %. In the NLFEA modelled beams, it had been noticed that the more the beam's depth, the less the shear span-to-depth ratio; as that ratio was 2.7 at a depth of 225 mm, where the ratio became 1.2 at a depth of 450 mm. The depth, of strengthened and control beams, was more influential on the beam's ultimate load than the resultant deflections. Also, the attained findings pointed out that the RC beam's depth had affected the cracking angle; as it was: 33°, 44°, 50°, and 54° at a beam's shear span-to-depth ratio of: 2.7, 1.9, 1.5, and 1.2, respectively. Had a shear crack exceeded the length of a CFRP strip, the stirrup would fail to get to its yield strength. In this case, the influence of the beams' depth is limited. Finally, the obtained NLFEA results were evaluated by comparing them to well-known shear strength models. 10.34910/MCE.105.1 reinforced concrete beam depth shear flexural strength fiber reinforced polymer nonlinear finite element analysis https://engstroy.spbstu.ru/article/2021.105.1/
RAR RUS 10502-10502 https://orcid.org/0000-0002-6232-6642 Stellenbosch University Babafemi Adewumi John ajbabafemi@sun.ac.za
Stellenbosch, South Africa
 Obafemi Awolowo University Akinola Olayemi Temilorun akinolaolayemi@ymail.com
Ile-Ife, Nigeria
 School of Architecture, Building and Civil Engineering, Loughborough University Kolawole John Temitope j.t.kolawole@lboro.ac.uk
Loughborough, UK
 International University of Business Agriculture and Technology Paul Suvash Chandra suvashpl@iubat.edu
Dhaka, Bangladesh
 57191381045 0000-0002-3021-8591 University of Asia Pacific Miah Md. Jihad jihad.miah@uap-bd.edu
Dhaka, Bangladesh
 Effect of sawdust ash and laterite on the electrical resistivity of concrete This study is an experimental research aimed at evaluating the electrical resistivity of concrete containing laterite and sawdust ash (SDA). Laterite was used to partially replace the sand in concrete while SDA partially replaced cement as a supplementary cementitious material. Cylindrical samples of Ø100 by 200 mm were used to evaluate the singular and combined influences of water-binder ratio, SDA and laterite on the electrical resistivity of concrete as a measure of durability. The sawdust ash content of 0, 10, 20 and 30% by weight of cement was considered while an optimum 30 % laterite content was examined and water-binder ratios of 0.35, 0.50 and 0.65. Additionally, some samples were cured in 1 %, 3 % and 5 % of sodium chloride salt (NaCl) to simulate the marine environment. The electrical resistivity test was conducted using the four-electrode method (Wenner’s Method) in accordance with ASTM C1202. The results of the investigations revealed that the resistivity of concrete generally increases with age at all replacement levels with optimum performance at a water-binder ratio of 0.50. Also, the results show that an increase in the sawdust ash content reduces the resistivity of concrete while the addition of laterite at 30% increases the electrical resistivity of concrete at increased water content. Chloride ion exposure generally reduces the ER of concrete while laterite reduces the impact of the chloride ion. 10.34910/MCE.105.2 laterite sawdust ash electrical resistivity durability water-cement ratio laterized concrete https://engstroy.spbstu.ru/article/2021.105.2/
RAR RUS 10504-10504 56548386400 https://orcid.org/0000-0002-4023-7382 Wasit University Abid Sallal sallal@uowasit.edu.iq
Wasit-Kut, Iraq
 57213170866 0000-0002-2134-3032 Wasit University Ali Sajjad sajad_alzuhery@yahoo.com
El'-Kut, Iraq
 57201032483 0000-0002-6573-4449 Wasit University Goaiz Hussam hussam@uowasit.edu.iq
El'-Kut, Iraq
 57210861969 0000-0002-9379-5935 Wasit University Al-Gasham Thaar thaar@uowasit.edu.iq
El'-Kut, Iraq
 0000-0003-1403-4992 Wasit University Kadhim Ahmed alkadhum.wasit@gmail.com
El'-Kut, Iraq
 Impact resistance of steel fiber-reinforced self-compacting concrete Among the adopted test methods to evaluate the impact resistance of materials and structural members is the drop-weight impact test. The ACI 544-2R repeated drop-weight impact testing technique was used in this research to evaluate the impact resistance of Self-Compacting Concrete (SCC) reinforced with micro-steel fibers. SCC concrete sample were made with two concrete grades and four fiber volumetric contents of 0, 0.5, 0.75 and 1.0 %. Another investigated parameter is the shape of the test specimen, where disk specimens (150 mm diameter and 65 mm thickness), 70 mm cubes and 70×70×260 mm beams were tested. The experimental results showed continuous improvement of impact resistance of SCC as the fiber content increased with percentage improvements ranging from 110 to 1200 % compared to the plain SCC. The failure impact resistance of the high strength SCC was higher than that of normal strength SCC regardless of specimen type and fiber content. The test results also showed that the impact resistance of disk specimens were clearly higher than those of cubes and beams and has more uniform variation with fiber content. 10.34910/MCE.105.4 concrete steel fibers self-compacting concrete fiber-reinforced concrete impact https://engstroy.spbstu.ru/article/2021.105.4/
RAR RUS 10505-10505 0000-0002-8769-9875 CECOS University of IT and Emerging Sciences Bashir Muhmmad Tariq tariqbashir@cecos.edu.pk
Peshawar, Pakistan
 0000-0003-4197-4197 Qurtuba University of Science & Information Technology, Department of Civil Engineering Daniyal Muhmmad drmtb@qurtuba.edu.pk
Dera Ismail Khan, Pakistan
 0000-0002-8721-0777 Jouf University, Sakaka, Al-Jouf Alzara Majed arc_majed@hotmail.com
Saudi Arabia
 0000-0003-1324-6598 Jouf University Elkady Mahmoud m.s.h.kady@gmail.com
Sakaka, Al-Jouf, Saudi Arabia
 0000-0002-9062-7493 Jouf University Armghan Ammar aarmghan@ju.edu.sa
Sakaka, Al-Jouf, Saudi Arabia
 Self-sensing cement composite for traffic monitoring in intelligent transport system Self-sensing cement-based composite was used to monitor the flow of traffic volume. Composite material was prepared with numerous percentages of carbon black (CB) and activated granulated ground blast furnace slag (GGBFS). This economical and concrete friendly material having piezo resistive properties helped to detect the wheel pressure induced by the vehicles passing over it. Initially, the pressure sensitivity of different mix designs was investigated in the laboratory and the samples having more sensitivity to applied load were used on the real road test for vehicle detection. Mechanical and microstructural properties of hydrated cement composite filled with CB and GGBFS as an active filler were also explored. Scanning electron microscopy/Electron dispersive spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis were carried out to characterize the microstructure and hydration product development of different specimens at different curing ages. The tested cement composite gives a remarkable response to both compressive and vehicular loading with excellent mechanical and microstructural properties. The results also showed that the self-sensitive cement composite has a great potential to use as a device for traffic monitoring. 10.34910/MCE.105.5 granulated blast furnace slag (GGBFS) carbon black (CB) cement-based composites Piezo resistive properties traffic monitoring https://engstroy.spbstu.ru/article/2021.105.5/
RAR RUS 10506-10506 56882996000 0000-0002-3668-899X Kostroma State University Fedotov Alexander aafedotoff@yandex.ru
Kostroma, Russia
 57189525518 0000-0002-7201-5979 Kostroma State University Vahnina Tatiana t_vachnina@mail.ru
Kostroma, Russia
 16242836100 0000-0002-7295-8934 Kostroma State University Susoeva Irina i.susoeva@yandex.ru
Kostroma, Russia
 Resistance to temperature and humidity changes of construction plywood and thermal-insulation boards Plywood and thermal-insulation boards with phenol-formaldehyde binder (PF), like other composites for construction purposes, must have long-term strength with changing temperature and humidity. The insufficient degree of curing of the phenol-formaldehyde binder reduces the hydrolytic stability of the material. The aim of the study is to increase the long-term strength of materials when exposed to changes in temperature and humidity by improving the structure formation of composites with the introduction of modifying additives in the binder. In the work, the method of cyclic testing of materials “soaking – freezing – thawing – drying” was used. After each cycle, the strength of the samples was determined. Nine modifying additives to the phenol-formaldehyde binder were used – hydrogen peroxide, metal salts, sulfosalicylic acid, dimethylglyoxime. The proportion of additives varied from 0.5 to 1.5 %. Graphic dependences of changes in the strength of PF plywood and thermal-insulation boards from plant waste after cyclic tests are given. Materials on a modified binder have long-term resistance to variable temperature and humidity effects. Plywood on a phenol-formaldehyde binder with the addition of 0.5 % sulfosalicylic acid has, after 15 test cycles, a 2.8 times higher residual strength compared to plywood on an unmodified binder. Thermal-insulation composites from plant waste on a modified binder after cyclic tests have a strength of 9 % higher than plates on an unmodified binder. 10.34910/MCE.105.6 wood composites phenol-formaldehyde binder modification structure temperature humidity strength https://engstroy.spbstu.ru/article/2021.105.6/
RAR RUS 10507-10507 278641 0000-0002-9947-0138 Pharos University in Alexandria El-Nadoury Wegdan wegdanelnadoury@gmail.com
Alexandria, Egypt
 Production of sustainable concrete using sawdust Rapid progression of construction industry rises the demand on building materials. With focusing on developing cost effective, sustainable and eco-friendly buildings, there is a need to find alternative materials to fulfil the constructions’ requirements. This paper presents an experimental study to investigate the applicability of using sawdust and sawdust ash as a green alternative for natural sand and cement respectively in order to lessen both environmental impacts and construction cost. The proposed mixtures incorporate sawdust with 5 %, 10 %, 15 %, 20 %, 25 % and 30 % as partial substitution for each of natural sand and cement. Mechanical properties of proposed mixes were compared to reference mixtures with typical concrete constituents. Physical properties were also investigated. The test results reveal that the optimum percentage of replacement of natural sand for producing sawdust concrete mixture is 10 % to 20 % and the acceptable percent of partial replacement of cement with sawdust ash is up to 15 %. 10.34910/MCE.105.7 mechanical properties aggregate Portland cement building materials sustainability sawdust cost https://engstroy.spbstu.ru/article/2021.105.7/
RAR RUS 10508-10508 57203908512 0000-0003-4690-5094 Universiti Tun Hussein Onn Malaysia Basri Kasbi hf170042@siswa.uthm.edu.my
Johor, Malaysia
 0000-0002-7550-4970 Universiti Tun Hussein Onn Malaysia Zainorabidin Adnan adnanz@uthm.edu.my
Johor, Malaysia
 0000-0002-9166-1159 Universiti Malaysia Sabah Mohamad Habib Musa habibmusa@ums.edu.my
Sabah, Malaysia
 0000-0002-7442-0134 Universiti Malaysia Sabah Musta Baba babamus@ums.edu.my
Sabah, Malaysia
 Determining the peat soil dynamic properties using geophysical methods The small strain dynamic properties of peat soil are a fundamental parameter related to the mechanical behaviour of a structure constructed on peat ground. These parameters are used in evaluation of the dynamic behaviour and seismic design in geotechnical structures. Determination of dynamic properties of peat soil is often done using laboratory-based tests that risk overestimation and underestimation due to sample disturbance. Since geophysical methods are proven to be able to obtain small strain dynamic properties with similar magnitude as the laboratory tests, it has become popular and is increasingly used in practice. Two geophysical methods known as multichannel analysis of surface waves (MASW) and seismic refraction were performed in this study to estimate the small strain maximum shear modulus (Gmax) and maximum elastic modulus (Emax). The results showed the value of Gmax and Emax were ranging from 1.01 to 6.83 MPa and from 3.88 to 10.9 MPa respectively. Correlations were also established to assist in estimating Gmax and Emax on peat soil with bulk density. There appears to be a particularly good link between the Gmax, Emax and bulk density. Overall, the small strain dynamic properties determined shows significant increment with depth which could be governed primarily by the effective stress. Other parameters such as water content, bulk density, organic content and degree of decomposition also could significantly influence the dynamic properties of peat soil. 10.34910/MCE.105.8 peat dynamic properties shear wave velocity shear modulus elastic modulus https://engstroy.spbstu.ru/article/2021.105.8/
RAR RUS 10509-10509 St. Petersburg State University of Architecture and Civil Engineering Kaldar-ool Anay-Khaak oorzhaka-h@mail.ru 56865882600 St. Petersburg State University of Architecture and Civil Engineering Glukhikh Vladimir tehmeh@spbgasu.ru
St. Petersburg, Russia
 57191250155 0000-0002-7796-2350 St. Petersburg State University of Architecture and Civil Engineering Opbul Eres fduecnufce@mail.ru
St. Petersburg, Russia
 Tuvan State University Saaya Svetlana sedip@mail.ru
Kyzyl, Russia
 Stress condition of brick barrel vaults in view of anisotropic properties The subject of our studies are brickwork barrel vaults used in historic buildings and structures. To keep flat-arched vaults in good working order, it is required to perform appropriate theoretical research aimed at studying their stress condition. It is necessary to find elastic constants in a new coordinate system in complex curved objects consisting of bricks and mortared joints. To determine elastic constants, we used brickwork strength characteristics obtained from experiments on the basis of known formulas, studied the elastic modulus of bricks and mortar, found the elastic modulus of brickwork with the help of rheology method and used the elasticity parameters interconnecting elastic constants of cylindrical anisotropic bodies in the principal anisotropy directions in new coordinate systems. When assessing the load-bearing capacity of flat-arched vaults, it is possible to determine primary stress values using elastic constants in new coordinate systems with the help of the finite elements method using computer software. 10.34910/MCE.105.9 barrel vaults brickwork elasticity modulus elasticity constants elasticity parameters orthotropic-anisotropic material cylindrical anisotropy https://engstroy.spbstu.ru/article/2021.105.9/
RAR RUS 10510-10510 “B.E. Vedeneev VNIIG”, JSC Kozhurova Alexandra bagmut_alex@list.ru
St. Petersburg, Russia
 56825663400 0000-0003-4172-7591 “B.E. Vedeneev VNIIG”, JSC Shipilov Alexander a.shipilov@yahoo.com
St. Petersburg, Russia
 Assessment of wave impact on hydraulic structures of the Flood Prevention Facility Complex of St. Petersburg obtained from field observations The article describes an attempt to estimate wave parameters from available data of the average and maximum wave heights impacted to hydraulic structures of the FPFC of St. Petersburg obtained from field observations. The methodology was developed to estimate wave heights of the set repeatability during storms, with application of the Monte Carlo method and method of the inverse transform of Smirnov. Convergence of the empirical and model distributions was checked by using the Kolmogorov-Smirnov criterion. Field data analysis shows some storms that took place within the observed period could be characterized by wave heights (h1 %) exceeding the designed ones. 10.34910/MCE.105.10 wave wave height Gulf of Finland Monte Carlo method field observations https://engstroy.spbstu.ru/article/2021.105.10/
RAR RUS 10511-10511 Riga Technical University Sprince Andina andina.sprince@rtu.lv 57211205458 0000-0003-4280-0025 Riga Technical University Gailitis Rihards rihards.gailitis@rtu.lv
Riga, Latvia
 H-5843-2013 57205122537 0000-0002-8367-7927 Riga Technical University Pakrastins Leonids leonids.pakrastins@rtu.lv 57211205950 0000-0002-6983-3874 Riga Technical University Kozlovskis Tomass tomass.kozlovskis@rtu.lv
Riga, Latvia
 M-6585-2013 6508103761 0000-0002-1196-8004 Peter the Great Saint Petersburg Polytechnic University Vatin Nikolai vatin@mail.ru
Polytechnicheskay, 29
 Long-term properties of cement mortar under compression, tension, and 3-point bending Cement composite long-term property assessment usually is limited to the compression strain state due to the difficulty of performing long-term tests in tension and 3-point bending. This paper shows the difference in long-term properties in compression, tension, and 3-point bending for plain ordinary Portland cement mortar (OPC). The obtained results were compared to reinforced specimen results to determine whether the PVA refibres improve the long-term properties of OPC mortar in various stress-strain conditions. Cylinders, compact tension specimens (CT), and beams – plates were prepared to evaluate material properties and the role of fibre reinforcement in these different stress states. Additionally, to conventional surface-attached strain gauges, 2D-DIC was employed to observe the creep strain of specimens in tension. This paper aim to determine long-term property differences in compression, tension and 3-point bending and, also, to see if low amount PVA fibre incorporation improve long-term properties in previously stated stress-strain states. It was determined that the usage of 1 % of PVA fibres increases creep strains in compression on average by 15 % and reduced by 7 % in tension. It reduces shrinkage strain by 18 % in compression and 8 % in tension. The long-term deflection for the PVA fibre-reinforced specimens are, on average by 55 % higher than for plain OPC mortar specimens in 3-point bending. 10.34910/MCE.105.11 long-term properties creep shrinkage compression tension 3-point bending digital image correlation PVA fibre OPC mortar https://engstroy.spbstu.ru/article/2021.105.11/
RAR RUS 10512-10512 57200287767 Siberian Federal University Koyankin Alexandr KoyankinAA@mail.ru 12795222600 Novosibirsk state University of architecture and construction Mitasov Valery mitassovv@mail.ru A deformed state of the composite frame with phased installation Experimental studies have been carried out to investigate the features of a composite flat frame deformation that arise in the process of its gradual installation and loading. During the first stage only precast elements (columns and beam precast parts) are assembled, which are further loaded with some weight that simulates its own weight in a real structure, the weight of other precast elements and that of monolithic concrete. Thus, at the first stage of existence the load is perceived only by the precast elements of the flat frame. Subsequently, at the second stage, without removing the previously applied load, the monolithic concrete is laid, which, having gained the required strength is included in the deformation process, taking an additional applied load that simulates the weight of floor structures, partitions, curtain walls and operational load. The motivations for conducting experimental research were as follows: the carcass of a composite building (is simulated by a flat double two-story frame in the experiment) in real conditions is built in stages, which is expressed in serial installation of individual components. These design features lead not only to the inclusion of separate parts of composite elements in the deformation process at different times, but also to a significant change in the design scheme as a whole (the formation of continuous beams and floor slabs, an appearance of a rigid junction of beams with columns, an increase in the degree of static indefinability of the system, and so on). Experimental studies of the stress-strain state of composite flat frames were performed, taking into account the phased installation process and changes in the design scheme. Precast parts of experimental flat frames (columns, beam precast parts) are made of heavy concrete, and monolithic beam parts – of light concrete (expanded- clay concrete). The conducted research allows us to state that the phased installation and involvement in the deformation process of both individual elements of the composite carcass and the constituent parts of the elements significantly change the picture of the carcass deformation. 10.34910/MCE.105.12 reinforced concrete compressive strength cracks tensile strength experimental investigations prefabricated-monolithic structures https://engstroy.spbstu.ru/article/2021.105.12/
RAR RUS 10513-10513 National Research Moscow State University of Civil Engineering Kabantsev Oleg ovk531@gmail.com
Moscow, Russia
 6602444316 LLC Research and Production Company “SCAD Soft” Perelmuter Anatoliy avp@scadsoft.com
Kiev, Ukraine
 Plastic behavior particularities of structures subjected to seismic loads For the majority of buildings and structures, the analysis of seismic effects is performed employing the linear-spectral method, and is included into the design regulations of different countries. The linear-spectral analytical method allows for estimating the inelastic deformations in structures by reducing (decreasing) the actual seismic load by means of the coefficient of reduction. The current method of the seismic load reduction corresponds to the elastic-plastic type of structural deformation, with the coefficient of reduction applied to the load-bearing system as a whole. Nonetheless, this deformation pattern is not the only one available. There are structures and structural materials that trigger the elastic-brittle mechanism of transition to the limit state. The constructed buildings and facilities normally contain the structural elements of various deformation patterns (combined structural schemes), and that requires consideration when choosing the calculation method. Employing a universal coefficient of reduction in the design calculations of the combined structural schemes leads to an inaccurate result. Opposite to this, the authors propose herein a solution to the problem of accounting for the joint activity of elastic-plastic and elastic-brittle elements being part of the entire structure based on the energy method. Studied is the combined design model with a single degree of freedom and consisting of elements with different mechanisms of inelastic deformation. Various scenarios of conditions for the joint deformation of heterogeneous elements are analyzed. The general solution to the problem of the coefficient of reduction value for the load-bearing systems made of the elements of different types of inelastic deformation depends on the ratio of stiffness values of the elastic-plastic and elastic-brittle subsystems in structures, as well as on the ratio of bearing capacity of such subsystems. General solutions are obtained to the problem of the maximum permissible value of the coefficient of plasticity for the combined load-bearing system that is responsible for safety of the elastic-brittle sections in structures, and for the system as a whole. When employing the linear-spectral method to calculate the seismic effects for individual parts in structures, it is suggested to use differentiated coefficients of reduction, which is, in fact, complies with the actual performance pattern of structures. 10.34910/MCE.105.13 stress-strain state limit state of structures plastic strain elastic brittle fracture coefficient of reduction https://engstroy.spbstu.ru/article/2021.105.13/
RAR RUS 10514-10514 56826013600 Peter the Great St. Petersburg Polytechnic University Gravit Marina marina.gravit@mail.ru
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
 57197818952 0000-0002-9822-3637 Graz University of Technology Dmitriev Ivan i.i.dmitriev@yandex.ru
Graz, Austria
 Thin-walled compressed steel constructions under fire load The article demonstrates the both theoretical and actual fire resistance limits of the composite I-shaped and box-shaped thin-walled steel structures in compression conditions under the standard fire load. The calculation was based on the Eurocode 3 and finite element modeling of high-temperature fields in SOFiSTiK PC. The experimental tests were carried out on the basis of design data to validate the results of both the calculation and modeling. It is shown that the static part of the calculation of the critical temperature, upon irreversible plastic deformations occur, is solved not completely correctly by means of regulations. In average the calculated critical temperature exceeds the actual one on 50-80 °C. It is shown that the assumption of a critical temperature equals to 350 °C is unreasonably low. The complex graphs of the temperature growth for each steel construction are given according to the paragraphs of normative documents, the finite-element modeling and results of thermocouple indicators for the fire tests. The solution of thermophysical part of calculation according to Eurocode 3 showed good convergence with the results of the experimental data, including the samples with effective fire protection, but strongly depend on the step of calculation. The accurate results were reached only when the time step equals 1 sec. The finite element modeling predicted the correct time to achieve the critical temperature of the tested sample without any additional assumptions. The MBOR-16F material produced by TIZOL JSC was used as a flame protection. This is new material, which has not been previously studied yet. The recommendations on application of the finite element programs are given in the thermophysical part of the fire resistance calculation. 10.34910/MCE.105.14 steel construction thin walled structures cold-formed steel structural design fire fire safety fire protection fire design https://engstroy.spbstu.ru/article/2021.105.14/