Advance of Reinforced Concrete

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Civil Engineering".

Deadline for manuscript submissions: closed (30 November 2022) | Viewed by 29531

Special Issue Editors

Department of the Transport Systems, Don State Technical University, 344002 Rostov Oblast, Russia
Interests: mechanical properties; finite element analysis; structural analysis; structural dynamics; finite element modeling; mechanical behavior of materials; mechanical testing construction; construction engineering mechanics of materials
Special Issues, Collections and Topics in MDPI journals
Department of Engineering Geology, Bases and Foundations, Don State Technical University, 344000 Rostov-on-Don, Russia
Interests: technology and organization of construction; technology and products from heavy and cellular concrete; quality control; technology and organization of testing of building materials and products; legislation and regulatory and technical documentation in construction
Special Issues, Collections and Topics in MDPI journals
Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344000 Rostov-on-Don, Russia
Interests: building constructions; buildings; structures; materials; products of heavy and aerated concrete; specifications and technical documentation in the construction and quality control in construction
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The special issue is to develop existing theories and gain new knowledge related to the need to obtain improved concrete compositions, reinforced concrete products, and structures. Unique analytical, mathematical, chemical, and experimental methods for studying the structure of concrete, the development of new formulations and technologies, including the activation of various components of concrete and reinforced concrete to improve the characteristics of buildings and structures obtained from these materials, are seen as critical scientific areas. Therefore, articles with numerical experiments, experimental laboratory studies, analysis of the data obtained using mathematical methods, mechanical calculations, deformation calculations, and investigations on concrete structure are welcome.

Prof. Dr. Alexey Beskopylny
Dr. Evgenii Shcherban
Dr. Sergei Stel’makh
Guest Editors

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Published Papers (12 papers)

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Research

20 pages, 6218 KiB  
Article
Composition Component Influence on Concrete Properties with the Additive of Rubber Tree Seed Shells
by Alexey N. Beskopylny, Evgenii M. Shcherban’, Sergey A. Stel’makh, Besarion Meskhi, Alexandr A. Shilov, Valery Varavka, Alexandr Evtushenko, Yasin Onuralp Özkılıç, Ceyhun Aksoylu and Memduh Karalar
Appl. Sci. 2022, 12(22), 11744; https://doi.org/10.3390/app122211744 - 18 Nov 2022
Cited by 38 | Viewed by 2601
Abstract
The growth in the volume of modern construction and the manufacture of reinforced concrete structures (RCSs) presents the goal of reducing the cost of building materials without compromising structures and opens questions about the use of environmentally friendly natural raw materials as a [...] Read more.
The growth in the volume of modern construction and the manufacture of reinforced concrete structures (RCSs) presents the goal of reducing the cost of building materials without compromising structures and opens questions about the use of environmentally friendly natural raw materials as a local or full replacement of traditional mineral components. This can also solve the actual problem of disposal of unclaimed agricultural waste, the features of which may be of interest to the construction industry. This research aimed to analyze the influence of preparation factors on concrete features with partial substitution of coarse aggregate (CA) with rubber tree (RT) seed shells and to determine the optimal composition that can make it possible to attain concrete with improved strength features. CA was replaced by volume with RT seed shells in an amount from 2% to 16% in 2% increments. Scanning electronic microscopy was employed to investigate the structure of the obtained concrete examples. The maximum increase in strength features was observed when replacing coarse filler with 4% RT seed shell by volume and amounted to, for compressive and axial compressive strength (CS) and tensile and axial tensile strength (TS) in twisting, 6% and 8%, respectively. The decrease in strain features under axial compression and under axial tension was 6% and 5%, respectively. The modulus of elasticity increased to 7%. The microstructure of hardened concrete samples with partial replacement of CA with RT seed shells in the amount of 2%, 4% and 6% was the densest with the least amount of pores and microcracks in comparison with the structure of the sample of the control composition, as well as samples with the replacement of CA with RT seed shells in an amount of more than 6%. The expedient effective replacement of CA with RT shells led to a reduction in battered stone of up to 8%. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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20 pages, 8132 KiB  
Article
Normal-Weight Concrete with Improved Stress–Strain Characteristics Reinforced with Dispersed Coconut Fibers
by Evgenii M. Shcherban’, Sergey A. Stel’makh, Alexey N. Beskopylny, Levon R. Mailyan, Besarion Meskhi, Alexandr A. Shilov, Andrei Chernil’nik, Yasin Onuralp Özkılıç and Ceyhun Aksoylu
Appl. Sci. 2022, 12(22), 11734; https://doi.org/10.3390/app122211734 - 18 Nov 2022
Cited by 42 | Viewed by 3377
Abstract
According to the sustainable development concept, it is necessary to solve the issue of replacing fiber from synthetic materials with natural, environmentally friendly, and cheap-to-manufacture renewable resources and agricultural waste. Concrete is the primary material for which fibers are intended. Therefore, the use [...] Read more.
According to the sustainable development concept, it is necessary to solve the issue of replacing fiber from synthetic materials with natural, environmentally friendly, and cheap-to-manufacture renewable resources and agricultural waste. Concrete is the primary material for which fibers are intended. Therefore, the use of vegetable waste in concrete is an essential and urgent task. Coconut fiber has attracted attention in this matter, which is a by-product of the processing of coconuts and makes it relevant. This work aims to investigate the experimental base for the strength properties of dispersed fiber-reinforced concrete with coconut fibers, as well as the influence of the fiber percentage on the mechanical, physical, and deformation characteristics. The samples were made of concrete with a compressive strength at 28 days from 40 to 50 MPa. The main mechanical characteristics such as strength in compression (cubic and prismatic) and tension (axial and bending), as well as the material’s compressive and tensile strains, were investigated. The percentage of reinforcement with coconut fibers was taken in the range of 0% to 2.5% with an increment of 0.25 wt.%. Tests were carried out 28 days after the manufacture. The microstructure of the resulting compositions was investigating using the electron microscopy method. The most rational percentage of coconut fibers was obtained at 1.75%. The increase in mechanical indicators was 24% and 26% for compression and axial compression, respectively, and 42% and 43% for tensile bending and axial tension, respectively. The ultimate strains in compression were raised by 46% and in tension by 51%. The elastic modulus was increased by 16%. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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19 pages, 1540 KiB  
Article
Concrete Strength Prediction Using Machine Learning Methods CatBoost, k-Nearest Neighbors, Support Vector Regression
by Alexey N. Beskopylny, Sergey A. Stel’makh, Evgenii M. Shcherban’, Levon R. Mailyan, Besarion Meskhi, Irina Razveeva, Andrei Chernil’nik and Nikita Beskopylny
Appl. Sci. 2022, 12(21), 10864; https://doi.org/10.3390/app122110864 - 26 Oct 2022
Cited by 14 | Viewed by 2124
Abstract
Currently, one of the topical areas of application of machine learning methods in the construction industry is the prediction of the mechanical properties of various building materials. In the future, algorithms with elements of artificial intelligence form the basis of systems for predicting [...] Read more.
Currently, one of the topical areas of application of machine learning methods in the construction industry is the prediction of the mechanical properties of various building materials. In the future, algorithms with elements of artificial intelligence form the basis of systems for predicting the operational properties of products, structures, buildings and facilities, depending on the characteristics of the initial components and process parameters. Concrete production can be improved using artificial intelligence methods, in particular, the development, training and application of special algorithms to determine the characteristics of the resulting concrete. The aim of the study was to develop and compare three machine learning algorithms based on CatBoost gradient boosting, k-nearest neighbors and support vector regression to predict the compressive strength of concrete using our accumulated empirical database, and ultimately to improve the production processes in construction industry. It has been established that artificial intelligence methods can be applied to determine the compressive strength of self-compacting concrete. Of the three machine learning algorithms, the smallest errors and the highest coefficient of determination were observed in the KNN algorithm: MAE was 1.97; MSE, 6.85; RMSE, 2.62; MAPE, 6.15; and the coefficient of determination R2, 0.99. The developed models showed an average absolute percentage error in the range 6.15−7.89% and can be successfully implemented in the production process and quality control of building materials, since they do not require serious computing resources. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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15 pages, 3160 KiB  
Article
Experimental Study and Modelling on the Structural Response of Fiber Reinforced Concrete Beams
by Vitalijs Lusis, Krishna Kiran Annamaneni, Olga Kononova, Aleksandrs Korjakins, Inga Lasenko, Rengasamy Kannathasan Karunamoorthy and Andrejs Krasnikovs
Appl. Sci. 2022, 12(19), 9492; https://doi.org/10.3390/app12199492 - 22 Sep 2022
Cited by 12 | Viewed by 1596
Abstract
In many structural applications, concretes reinforced with short metal or synthetic fibers (fiber-reinforced concrete (FRC)) have a number of advantages over traditional concretes reinforced with steel rebars reinforcement, such as easier and more economical production, wear resistance, impact resistance, integrity, etc. In the [...] Read more.
In many structural applications, concretes reinforced with short metal or synthetic fibers (fiber-reinforced concrete (FRC)) have a number of advantages over traditional concretes reinforced with steel rebars reinforcement, such as easier and more economical production, wear resistance, impact resistance, integrity, etc. In the present study, several concrete mixes were developed and prismatic FRC specimens were fabricated. Their structural behaviors were studied using bending tests until prisms were fractured. Two types of fibers, namely, steel and polypropylene (PP) and three different concrete matrixes were investigated, testing in total 12 FRC prismatic specimens. Every group of FRC had the same concrete matrix, but different internal fiber architecture. All specimens were tested by Four-Point Bending (4PBT). The analysis was carried out with a goal to determine the workability and flexural tensile strength of all FRC groups, comparing these parameters with fracture modelling results. Single crack formation and opening model were established. Crack is crossing whole stretched part of the prism’s orthogonal crossection. Crack is opening, fibers are bridging the crack and are pulling out. Load bearing curves in the model were compared with experimentally obtained. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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20 pages, 13866 KiB  
Article
Enhanced Performance of Concrete Dispersedly Reinforced with Sisal Fibers
by Alexey N. Beskopylny, Sergey A. Stel’makh, Evgenii M. Shcherban, Levon R. Mailyan, Besarion Meskhi, Alexandr A. Shilov, Nikita Beskopylny and Andrei Chernil’nik
Appl. Sci. 2022, 12(18), 9102; https://doi.org/10.3390/app12189102 - 10 Sep 2022
Cited by 11 | Viewed by 1857
Abstract
The fibers used in concrete are mainly materials that require additional production, which negatively affects their cost and environmental friendliness. Therefore, the issue of the effectiveness of the use of natural fibers, the extraction of which does not require mechanized production, becomes relevant. [...] Read more.
The fibers used in concrete are mainly materials that require additional production, which negatively affects their cost and environmental friendliness. Therefore, the issue of the effectiveness of the use of natural fibers, the extraction of which does not require mechanized production, becomes relevant. One of these materials is sisal fiber. The main purpose of this work was to study the effect of adding sisal fibers on the structure and properties of environmentally friendly concretes with improved characteristics. The tests were carried out in strict accordance with technological recommendations and normative and technical documents. Laboratory samples were made in the form of cubes and prisms of concrete with a compressive strength of 48 MPa and sisal fiber content of 0.25%, 0.5%, 0.75%, 1.0%, 1.25% and 1.5%. The tests were carried out at a concrete age of 15 days. The compressive strength and tensile strength of concrete samples were studied using the method of optical microscopy. The optimal content of fiber reinforcement with sisal fiber was determined as equal to 1%. The increases in the strength characteristics of the obtained fiber-reinforced concrete samples at the optimal dosage of sisal fiber in an amount of 1% by weight of cement were 22% for compressive strength, 27% for axial compressive strength, 33% for tensile strength in bending and 29% for axial strength stretching. The increases in deformation characteristics were 25% for strains in axial compression, 42% for strains in axial tension and 15% for the elastic modulus. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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20 pages, 14467 KiB  
Article
Nanomodified Concrete with Enhanced Characteristics Based on River Snail Shell Powder
by Sergey A. Stel’makh, Evgenii M. Shcherban’, Alexey N. Beskopylny, Levon R. Mailyan, Besarion Meskhi, Nikita Beskopylny, Natal’ya Dotsenko and Maria Kotenko
Appl. Sci. 2022, 12(15), 7839; https://doi.org/10.3390/app12157839 - 04 Aug 2022
Cited by 9 | Viewed by 2622
Abstract
The utilization of aquaculture waste, such as snail shells, is a severe issue. These shells are common in water-sources and are a by-product of sifting sand for masonry and concrete work. Calcium-rich river shells are of great interest for cement building materials. In [...] Read more.
The utilization of aquaculture waste, such as snail shells, is a severe issue. These shells are common in water-sources and are a by-product of sifting sand for masonry and concrete work. Calcium-rich river shells are of great interest for cement building materials. In this regard, the purpose of this article was to develop a nanomodified concrete with improved characteristics based on the powder of snail shells. Experimental studies have confirmed the effectiveness of the use of river shells in concrete without a decrease in strength characteristics and deterioration of other properties. It has been found that the optimal replacement by the snail shell powder that replaced cement is in the amount of 6%. By the nanomodification of concrete with the powdered shells of river snails, it was possible to achieve an increase in compressive strength up to 12%, axial compressive strength—up to 8%, tensile strength in bending—up to 9%, axial tensile strength—up to 11%, elastic modulus—up to 8%. Concrete nanomodification with snail shell powder in the amount of 6% contributed to a reduction of deformations of up to 7%. The study of the microstructure of concrete samples nanomodified with snail shell powder confirmed the obtained dependences of the cement’s properties on the nanomodifier dosage, as well as the most effective dosage of snail shell powder. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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21 pages, 4060 KiB  
Article
Influence of Recipe Factors on the Structure and Properties of Non-Autoclaved Aerated Concrete of Increased Strength
by Sergey A. Stel’makh, Evgenii M. Shcherban’, Alexey N. Beskopylny, Levon R. Mailyan, Besarion Meskhi, Nikita Beskopylny, Natal’ya Dotsenko and Maria Kotenko
Appl. Sci. 2022, 12(14), 6984; https://doi.org/10.3390/app12146984 - 10 Jul 2022
Cited by 7 | Viewed by 1714
Abstract
At present, the load-bearing enclosing structures of buildings and structures are designed and built considering the increasing requirements for energy efficiency and energy saving of such structures. This is due to the need for a thrifty attitude to the energy consumed and the [...] Read more.
At present, the load-bearing enclosing structures of buildings and structures are designed and built considering the increasing requirements for energy efficiency and energy saving of such structures. This is due to the need for a thrifty attitude to the energy consumed and the need to strive for the greening of construction and increase the energy efficiency of buildings and structures. In this regard, one of the most effective and proven building materials is cellular concrete. The purpose of this study was to study the influence of some prescription factors on the structure formation and properties of non-autoclaved aerated concrete with improved characteristics. Standard test methods were used, as well as SEM analysis of the structure of aerated concrete. Non-autoclaved aerated concrete with the replacement of part of the cement with microsilica in an amount from 4% to 16% MS showed higher strength characteristics compared to aerated concrete, where part of the cement was replaced by the addition of granulated blast-furnace slag and a complex additive. The maximum value of compressive strength was recorded for aerated concrete with 16% MS addition. The largest increase in the coefficients of constructive quality was observed in compositions of aerated concrete with the addition of silica fume from 11% to 46% compared with the control composition. The addition of microsilica makes it possible to achieve an improvement in the thermal conductivity characteristics of non-autoclaved aerated concrete (up to 10%). Replacing part of the cement with slag and complex additives does not have a significant effect on thermal conductivity. The obtained dependencies were confirmed by the analysis of the structure formation of the studied aerated concrete at the micro level. An improvement in the microstructure of aerated concrete with the addition of microsilica in comparison with samples of the control composition has been proven. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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20 pages, 6897 KiB  
Article
Enhanced Eco-Friendly Concrete Nano-Change with Eggshell Powder
by Evgenii M. Shcherban’, Sergey A. Stel’makh, Alexey N. Beskopylny, Levon R. Mailyan, Besarion Meskhi, Valery Varavka, Nikita Beskopylny and Diana El’shaeva
Appl. Sci. 2022, 12(13), 6606; https://doi.org/10.3390/app12136606 - 29 Jun 2022
Cited by 13 | Viewed by 3977
Abstract
One of the unifying factors for all countries is the large consumption of chicken, and other, eggs in food and other types of economic activity. After using various types of eggs for their intended purpose, a large amount of waste accumulates in the [...] Read more.
One of the unifying factors for all countries is the large consumption of chicken, and other, eggs in food and other types of economic activity. After using various types of eggs for their intended purpose, a large amount of waste accumulates in the form of eggshells. Currently, this problem exists and needs a non-trivial, original solution. The aim of the work was to fill the scientific gap in the direction of studying the microstructure formation of improved nano-modified environmentally-friendly concrete based on eggshell powder and obtaining a concrete composition for the manufacture of an industrial sample of such a material. An environmentally-friendly concrete was obtained, the characteristics of which were improved relative to standard concrete by modifying it with eggshell powder, for which the optimal dosage was determined. The most effective was the replacement of part of the cement with eggshell powder in the amount of 10%. The maximum increase in strength characteristics ranged from 8% to 11%. The modulus of elasticity increased by 4% compared to the control samples without eggshell powder. The maximum reduction in deformations under axial compression and tension in comparison with the control values ranged from 5% to 10%. The study of the composite’s microstructure nano-modified with eggshell powder, and an analysis of the changes occurring in this microstructure due to nano-modification, confirmed the improvement in characteristics and the optimal dosage of eggshell powder. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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26 pages, 10684 KiB  
Article
Flexural Strength and Stiffness of Donut-Type Voided Slab
by Joo-Hong Chung, Hyung-Suk Jung and Hyun-Ki Choi
Appl. Sci. 2022, 12(12), 5782; https://doi.org/10.3390/app12125782 - 07 Jun 2022
Cited by 3 | Viewed by 1923
Abstract
The voided slab system has been known as an effective technique to replace a heavy reinforced concrete slab system without the decrease in flexural strength. However, according to the previous studies, the flexural capacities such as flexural strength, stiffness and ductility of the [...] Read more.
The voided slab system has been known as an effective technique to replace a heavy reinforced concrete slab system without the decrease in flexural strength. However, according to the previous studies, the flexural capacities such as flexural strength, stiffness and ductility of the voided slabs were practically lower than that of the solid slabs depending on the void shapes and details. Therefore, in this study, an analytical and experimental study were conducted to derive the optimal void shape and details focused on the flexural capacities of voided slabs. Based on a finite element (FE) analysis, a donut-type void shaper, which was a hexahedron with rounded edges and a hole penetrating the center, was suggested as the optimal shape in voided slabs, and an experimental study was conducted to verify flexural capacities of the donut-type voided slab. The flexural strength, stiffness and deflection of the donut-type voided slab were investigated by void shape and fixing method of void shaper as variables. The ductility of voided slab was also evaluated, because ductility is as important as strength for the safe design of slab member. The test results showed that the flexural strength of the donut-type voided slabs was equivalent to 98% and 105% that of the solid RC specimen, and the donut-type voided slab specimens had enough ductility for the flexural member. The stiffness of the donut-type voided slab was decreased about 8~9% compared with the solid slab, but it was improved up to 7% compared to the non-donut-type voided slab. Based on test results, the flexural design method of the donut-type voided slab associated with the void shape and fixing device of void shaper was suggested, and it was confirmed that the donut-type voided slab is one of the efficient alternatives to replace heavy flat plate slabs. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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17 pages, 6994 KiB  
Article
High-Performance Concrete Nanomodified with Recycled Rice Straw Biochar
by Alexey N. Beskopylny, Sergey A. Stel’makh, Evgenii M. Shcherban’, Levon R. Mailyan, Besarion Meskhi, Alla S. Smolyanichenko and Nikita Beskopylny
Appl. Sci. 2022, 12(11), 5480; https://doi.org/10.3390/app12115480 - 28 May 2022
Cited by 15 | Viewed by 2636
Abstract
The development of new and improvement of existing technologies based on the use of waste products from various industries or recyclable materials is a current trend in the construction industry. Including in the composition of binders and concrete by-products of industry, reducing the [...] Read more.
The development of new and improvement of existing technologies based on the use of waste products from various industries or recyclable materials is a current trend in the construction industry. Including in the composition of binders and concrete by-products of industry, reducing the proportion of Portland cement, it is crucial to maintain and improve the resulting products’ mechanical characteristics and life cycle. The main aim of the study was to investigate the influence of biochar additive on the microstructure and properties of the concrete and obtain the composition with improved characteristics due to nanomodification of rice straw recycled biochar. An environmentally friendly technology for concrete manufacture was obtained, using agricultural waste, rice straw, as its components, developing a composition of concrete nanomodified with processed rice straw biochar, identifying the dependences of concrete properties on their nanomodification with processed rice straw coal. It has been established that the most effective dosage is the addition of rice straw biochar in the amount of 6% by weight of cement. The improvement in the properties of concrete was expressed in the increase in its physical and mechanical characteristics and changes in deformability according to the results of the analysis of the stress-strain diagrams. The increase in strength characteristics ranged from 17% to 25%. The modulus of elasticity increased to 14%. The deformation characteristics decreased from 12% to 24%. Introducing a finely dispersed additive of rice straw biochar modified by the electromagnetic method leads to a decrease in cement consumption by up to 10%. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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18 pages, 3136 KiB  
Article
Increasing the Corrosion Resistance and Durability of Geopolymer Concrete Structures of Agricultural Buildings Operating in Specific Conditions of Aggressive Environments of Livestock Buildings
by Evgenii M. Shcherban’, Sergey A. Stel’makh, Alexey Beskopylny, Levon R. Mailyan and Besarion Meskhi
Appl. Sci. 2022, 12(3), 1655; https://doi.org/10.3390/app12031655 - 04 Feb 2022
Cited by 16 | Viewed by 2552
Abstract
The problem of increasing the service life of buildings and structures for agricultural purposes operated in aggressive environments is relevant. The aim and scientific novelty of the work were to determine the relationship between the structure and properties of geopolymer concretes in aggressive [...] Read more.
The problem of increasing the service life of buildings and structures for agricultural purposes operated in aggressive environments is relevant. The aim and scientific novelty of the work were to determine the relationship between the structure and properties of geopolymer concretes in aggressive environments. The properties of various concrete compositions under the influence of a solution of lactic, acetic, and oxalic acids were studied. With an exposure time of 90 days in an aggressive environment, samples of concrete based on a geopolymer binder had up to 6% less loss of strength and up to 10% less weight loss than concrete based on a cement binder. The effectiveness of the developed composition and technological solutions was confirmed, and it was quantitatively expressed in increased compressive strength and tensile strength in bending by 81.0% and 73.5%, respectively. It has been established that raising the heat treatment temperature to 80 °C leads to increased compressive strength for all compositions of geopolymer binders. The most favorable heat treatment conditions are created at 80 °C. The relations of the strength characteristics of geopolymer binders are revealed, which allow a detailed quantitative and qualitative assessment of the influence of the studied factors on the change in the system “composition—hardening conditions—properties” and can be used in the development of production compositions of binders and composites based on them, as well as their regulation—physical, mechanical, and operational characteristics. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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19 pages, 3694 KiB  
Article
Improvement of Strength and Strain Characteristics of Lightweight Fiber Concrete by Electromagnetic Activation in a Vortex Layer Apparatus
by Evgenii M. Shcherban’, Sergey A. Stel’makh, Alexey Beskopylny, Levon R. Mailyan, Besarion Meskhi and Anatoly Shuyskiy
Appl. Sci. 2022, 12(1), 104; https://doi.org/10.3390/app12010104 - 23 Dec 2021
Cited by 16 | Viewed by 1618
Abstract
The relevant problem of choosing effective materials for enclosing structures is compliance with the requirements of increased thermal resistance, reduced mass of buildings and structures, and reduced material consumption, labor intensity, and construction costs. These requirements are satisfied by structures made of lightweight [...] Read more.
The relevant problem of choosing effective materials for enclosing structures is compliance with the requirements of increased thermal resistance, reduced mass of buildings and structures, and reduced material consumption, labor intensity, and construction costs. These requirements are satisfied by structures made of lightweight fiber-reinforced concrete, which are the subject of attention of many scientists and engineers. One of the most rational requirements for industrial use is the activation of untreated components of the concrete mixture. This article is devoted to studying the influence of the activation of fiber-reinforced concrete elements in the vortex layer apparatus on concrete strength and structural characteristics. The effect of the raw component processing time of the concrete mixture on the strength and deformation characteristics of the lightweight fiber-reinforced concrete was studied. The optimal processing time for the cement–sand mortar in the VLA-75-85s was determined. It was shown that the activation of the vortex layer in the apparatus leads to an increase in strength from 27% to 61% and an improvement in the deformation characteristics of lightweight fiber-reinforced concrete by up to 12%. Furthermore, it was found that the use of activation in VLA leads to an increase in the coefficient of constructive quality for all experimentally determined strength characteristics of lightweight fiber-reinforced concrete by up to 27%. Full article
(This article belongs to the Special Issue Advance of Reinforced Concrete)
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