Pub Date : 2022-10-11DOI: 10.37538/2224-9494-2022-3(34)-103-113
V. Kaurkin, A. Kharichkin, A. Iospa
{"title":"APPLICATION OF THE HYDRATION HEAT OF CONCRETE BORED PILES WHEN USING FOUNDATION SOILS ACCORDING TO PRINCIPLE II (ACTIVE METHOD)","authors":"V. Kaurkin, A. Kharichkin, A. Iospa","doi":"10.37538/2224-9494-2022-3(34)-103-113","DOIUrl":"https://doi.org/10.37538/2224-9494-2022-3(34)-103-113","url":null,"abstract":"","PeriodicalId":169749,"journal":{"name":"Bulletin of Science and Research Center of Construction","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133156509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-11DOI: 10.37538/2224-9494-2022-3(34)-45-53
A. V. Eloyan, Jon Karapetyan, G. M. Matevosyan, R. Karapetyan
{"title":"OPTIMAL SUPPORT POSITIONING OF A RECTANGULAR PLATE IN A STABILITY PROBLEM UNDER TEMPERATURE FIELD EXPOSURE","authors":"A. V. Eloyan, Jon Karapetyan, G. M. Matevosyan, R. Karapetyan","doi":"10.37538/2224-9494-2022-3(34)-45-53","DOIUrl":"https://doi.org/10.37538/2224-9494-2022-3(34)-45-53","url":null,"abstract":"","PeriodicalId":169749,"journal":{"name":"Bulletin of Science and Research Center of Construction","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125294050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-11DOI: 10.37538/2224-9494-2022-3(34)-134-143
N. E. Urmanshina, Z. Mukhametzyanov
{"title":"STUDY INTO THE SIGNIFICANCE OF INDIVIDUAL ELEMENTS IN A PILED-RAFT FOUNDATION","authors":"N. E. Urmanshina, Z. Mukhametzyanov","doi":"10.37538/2224-9494-2022-3(34)-134-143","DOIUrl":"https://doi.org/10.37538/2224-9494-2022-3(34)-134-143","url":null,"abstract":"","PeriodicalId":169749,"journal":{"name":"Bulletin of Science and Research Center of Construction","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121273613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-11DOI: 10.37538/2224-9494-2022-2(33)-213-221
V. I. Nikitin
In this article, the meaning and purpose of the second part of the postgraduate course entitled History and Philosophy of Technology were briefly described.What is technology? How one can define its nature and historical purpose? Is technology always beneficial? What constitutes the reality of technical objects, and to what limits does it extend? What is the importance of technology for humankind, and how does it affect every aspect of human life? These and many other questions related to technology, the history of its development, and its increasing influence on the human life sphere are of practical, as well as theoretical and even epistemological, importance. A scientific discipline, the philosophy of technology, which emerged in the second half of the 19th century, seeks answers to these questions.The article addresses the problems that reveal how and on what basis the philosophy of technology emerged, why engineers were at the origin of its development, and what are the main goals and tasks of this philosophical discipline.
{"title":"Philosophy of Technology","authors":"V. I. Nikitin","doi":"10.37538/2224-9494-2022-2(33)-213-221","DOIUrl":"https://doi.org/10.37538/2224-9494-2022-2(33)-213-221","url":null,"abstract":"In this article, the meaning and purpose of the second part of the postgraduate course entitled History and Philosophy of Technology were briefly described.What is technology? How one can define its nature and historical purpose? Is technology always beneficial? What constitutes the reality of technical objects, and to what limits does it extend? What is the importance of technology for humankind, and how does it affect every aspect of human life? These and many other questions related to technology, the history of its development, and its increasing influence on the human life sphere are of practical, as well as theoretical and even epistemological, importance. A scientific discipline, the philosophy of technology, which emerged in the second half of the 19th century, seeks answers to these questions.The article addresses the problems that reveal how and on what basis the philosophy of technology emerged, why engineers were at the origin of its development, and what are the main goals and tasks of this philosophical discipline. ","PeriodicalId":169749,"journal":{"name":"Bulletin of Science and Research Center of Construction","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130500643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-10DOI: 10.37538/2224-9494-2022-2(33)-122-138
M. Mozgolov, E. V. Kozlova
Introduction. The analysis of analytical and computer-assisted calculations of waffle slabs shows that, depending on the established finite-element model and structure geometry, the forces in beams can vary significantly. As a rule, the analytical model is used as a reference when comparing bending moments. Examples available in the literature show that regardless of the slab geometry, the stiffness of individual central orthogonal beams or conditionally selected beams is used in the calculations when determining structural loads.Aim. In this work, the accuracy of resulting forces in the beams of straight waffle slabs was assessed using the stiffness of individual beams in the analytical calculation.Materials and methods. The work was carried out by comparing the bending moments obtained analytically and in the SCAD software by the finite-element method for beams having various stiffnesses in the central zones of straight waffle slabs. 12.0 × 12.0 m slabs square in plan having different aspect ratios of waffle were considered, as well as slabs having square 1.5 × 1.5 m waffles and different aspect ratios of spans. A T-beam-and-girder construction was used in the computer model.Results. The values of bending moments of slabs square in plan having square caissons calculated analytically and using the computer-assisted finite-element method coincide, being a particular case. The bending moments calculated analytically and using the finite-element method for rectangular slabs or slabs having rectangular caissons differ. As the ratio of the span or caisson sides increases, these deviations increase.Conclusions. In the general calculation, using the stiffnesses of individual central orthogonal beams or conditionally selected beams for the analytical determination of forces in the beams of straight waffle slabs leads to erroneous results.
{"title":"Use of analytical method for calculating stiffnesses of straight waffle slabs","authors":"M. Mozgolov, E. V. Kozlova","doi":"10.37538/2224-9494-2022-2(33)-122-138","DOIUrl":"https://doi.org/10.37538/2224-9494-2022-2(33)-122-138","url":null,"abstract":"Introduction. The analysis of analytical and computer-assisted calculations of waffle slabs shows that, depending on the established finite-element model and structure geometry, the forces in beams can vary significantly. As a rule, the analytical model is used as a reference when comparing bending moments. Examples available in the literature show that regardless of the slab geometry, the stiffness of individual central orthogonal beams or conditionally selected beams is used in the calculations when determining structural loads.Aim. In this work, the accuracy of resulting forces in the beams of straight waffle slabs was assessed using the stiffness of individual beams in the analytical calculation.Materials and methods. The work was carried out by comparing the bending moments obtained analytically and in the SCAD software by the finite-element method for beams having various stiffnesses in the central zones of straight waffle slabs. 12.0 × 12.0 m slabs square in plan having different aspect ratios of waffle were considered, as well as slabs having square 1.5 × 1.5 m waffles and different aspect ratios of spans. A T-beam-and-girder construction was used in the computer model.Results. The values of bending moments of slabs square in plan having square caissons calculated analytically and using the computer-assisted finite-element method coincide, being a particular case. The bending moments calculated analytically and using the finite-element method for rectangular slabs or slabs having rectangular caissons differ. As the ratio of the span or caisson sides increases, these deviations increase.Conclusions. In the general calculation, using the stiffnesses of individual central orthogonal beams or conditionally selected beams for the analytical determination of forces in the beams of straight waffle slabs leads to erroneous results. ","PeriodicalId":169749,"journal":{"name":"Bulletin of Science and Research Center of Construction","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130467735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-10DOI: 10.37538/2224-9494-2022-2(33)-173-182
V. Stepanova, T. Mukhamediev, K. Kudyakov, A. Buchkin, E. Yurin
Introduction. Reinforced concrete structures affected by various aggressive environments operate under off-center compression. Fiber-reinforced polymer (FRP) rebars replacing steel reinforcement in these structures are capable of increasing their durability and decreasing operating costs. However, the use of FRP rebars is limited by insufficient previous research into the methods of designing such constructions. The majority of international regulatory technical documents concerning the design of concrete structures reinforced with FRP rebars indicate the necessity of detailed studies into the stress-strain state of these structures under compression.Aim. To study the effect of longitude and shear reinforcement on load-bearing characteristic of stressed concrete samples reinforced with longitudinal glass fiber-reinforced polymer (GFRP) rebars.Materials and methods. The study was carried out using a concrete prism sample with different parameters of longitudinal and shear reinforcement. Five types of GFRP rebars differing in mechanical properties, as well as anchorage were considered. Shear reinforcement of the samples was performed with metal clamps at different pitches. The sample testing was fulfilled using centric compression with static load.Results. The strength values of compressed concrete samples reinforced with GFRP rebars were obtained. An increase of up to 19 % in the strength of compressed concrete samples reinforced with GFRP rebars was found in comparison with non-reinforced samples.Conclusions. The strength of compressed concrete elements increases when reinforced with glass fiber-reinforced polymer rebars. The degree of increase in the strength of such elements depends on the number of longitudinal reinforcements, as well as shear reinforcement pitch. The effect of the type of anchorage of GFRP rebars along with the values of its compression resistance on the strength of compressed concrete elements have not been established.
{"title":"Experimental studies into the strength of compressed concrete elements reinforced with fiber-reinforced polymer rebars","authors":"V. Stepanova, T. Mukhamediev, K. Kudyakov, A. Buchkin, E. Yurin","doi":"10.37538/2224-9494-2022-2(33)-173-182","DOIUrl":"https://doi.org/10.37538/2224-9494-2022-2(33)-173-182","url":null,"abstract":"Introduction. Reinforced concrete structures affected by various aggressive environments operate under off-center compression. Fiber-reinforced polymer (FRP) rebars replacing steel reinforcement in these structures are capable of increasing their durability and decreasing operating costs. However, the use of FRP rebars is limited by insufficient previous research into the methods of designing such constructions. The majority of international regulatory technical documents concerning the design of concrete structures reinforced with FRP rebars indicate the necessity of detailed studies into the stress-strain state of these structures under compression.Aim. To study the effect of longitude and shear reinforcement on load-bearing characteristic of stressed concrete samples reinforced with longitudinal glass fiber-reinforced polymer (GFRP) rebars.Materials and methods. The study was carried out using a concrete prism sample with different parameters of longitudinal and shear reinforcement. Five types of GFRP rebars differing in mechanical properties, as well as anchorage were considered. Shear reinforcement of the samples was performed with metal clamps at different pitches. The sample testing was fulfilled using centric compression with static load.Results. The strength values of compressed concrete samples reinforced with GFRP rebars were obtained. An increase of up to 19 % in the strength of compressed concrete samples reinforced with GFRP rebars was found in comparison with non-reinforced samples.Conclusions. The strength of compressed concrete elements increases when reinforced with glass fiber-reinforced polymer rebars. The degree of increase in the strength of such elements depends on the number of longitudinal reinforcements, as well as shear reinforcement pitch. The effect of the type of anchorage of GFRP rebars along with the values of its compression resistance on the strength of compressed concrete elements have not been established. ","PeriodicalId":169749,"journal":{"name":"Bulletin of Science and Research Center of Construction","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127118104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-10DOI: 10.37538/2224-9494-2022-2(33)-150-160
T. Mukhamediev, S. Maiorov
Introduction. According to experimental data, at a certain design, the strength of eccentrically compressed elements increases due to the work of a composite polymer reinforcement located in a compressed cross-sectional area. However, dependences for calculating the strength of eccentrically compressed elements, represented in acting regulations for the design of concrete structures with a composite polymer reinforcement, appear to be inapplicable for calculating the reinforcement compression stress and, therefore, require refinement.Aim. To develop a methodology for calculating the strength of eccentrically compressed concrete elements with a composite polymer reinforcement, considering the work of the latter in a compressed cross-sectional area.Materials and methods. Considering the work of a reinforcement in the compressed cross-sectional area, the methodology of calculating the strength of eccentrically compressed elements was developed taking into account the positions of current design standards and verified by the data of experimental studies performed by domestic and foreign researchers.Results. The results of methodology reliability tests were obtained using the experimental data of test samples with a carbon, glass, and basalt-plastic reinforcement of various profile types. During the calculation of eccentrically compressed elements using the proposed dependencies for calculating the height of an element compressed cross-sectional area, the accuracy and reliability were established to be comparable with those calculated according to dependencies adopted in current regulations for the design of concrete structures with a composite polymer reinforcement.Conclusions. The proposed dependencies for calculating the height of a compressed cross-sectional area provide the sufficient accuracy of strength calculations for eccentrically compressed concrete elements both with and without taking into account the compression work of a composite polymer reinforcement.
{"title":"Strength calculation of eccentrically compressed concrete elements with a composite polymer reinforcement","authors":"T. Mukhamediev, S. Maiorov","doi":"10.37538/2224-9494-2022-2(33)-150-160","DOIUrl":"https://doi.org/10.37538/2224-9494-2022-2(33)-150-160","url":null,"abstract":"Introduction. According to experimental data, at a certain design, the strength of eccentrically compressed elements increases due to the work of a composite polymer reinforcement located in a compressed cross-sectional area. However, dependences for calculating the strength of eccentrically compressed elements, represented in acting regulations for the design of concrete structures with a composite polymer reinforcement, appear to be inapplicable for calculating the reinforcement compression stress and, therefore, require refinement.Aim. To develop a methodology for calculating the strength of eccentrically compressed concrete elements with a composite polymer reinforcement, considering the work of the latter in a compressed cross-sectional area.Materials and methods. Considering the work of a reinforcement in the compressed cross-sectional area, the methodology of calculating the strength of eccentrically compressed elements was developed taking into account the positions of current design standards and verified by the data of experimental studies performed by domestic and foreign researchers.Results. The results of methodology reliability tests were obtained using the experimental data of test samples with a carbon, glass, and basalt-plastic reinforcement of various profile types. During the calculation of eccentrically compressed elements using the proposed dependencies for calculating the height of an element compressed cross-sectional area, the accuracy and reliability were established to be comparable with those calculated according to dependencies adopted in current regulations for the design of concrete structures with a composite polymer reinforcement.Conclusions. The proposed dependencies for calculating the height of a compressed cross-sectional area provide the sufficient accuracy of strength calculations for eccentrically compressed concrete elements both with and without taking into account the compression work of a composite polymer reinforcement. ","PeriodicalId":169749,"journal":{"name":"Bulletin of Science and Research Center of Construction","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128808233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-10DOI: 10.37538/2224-9494-2022-2(33)-106-121
S. S. Kaprielov, A. Sheynfeld, Al-Omais Dzhalal, A. S. Zaitsev, R. Amirov
Introduction. The article presents a technology of erecting of high-rise building's frame structures made of B60-B100 classes high-strength concretes. This technology includes a complex of processes and considers a number of special features, the most significant of which are connected with the specific character of high-strength concretes and concreting climatic conditions.Aim. To determine the main requirements for the technology of concreting and parameters of curing the monolithic structures of high-rise buildings made of B60-B100 classes high-strength concretes, including at winter periods, at the various stages of their erection.Methods and materials. Studies were carried out on the effect of hardening temperature variations from +5 to +50 °С on the hardening kinetics of B60, B80, and B100 classes concretes. Based on the 15-year experience of the “Moscow-City” construction, the mix proportions of high-strength concretes were optimized, as well as the main technological parameters of concreting and curing the frame structures located at an altitude of up to 370 m were analyzed and summarized.Results. The mix proportions of B60-B100 classes concretes of high-workability and self-compacting mixtures with a cement consumption of 350–480 kg/m3 was optimized using standard materials and MB-type organomineral modifiers. The performed study revealed a regularity between the strength and the temperature-temporal parameter of concrete curing, which is applicable for a preliminary assessment of strength characteristics in high-strength concrete structures on the basis of their temperature measurement results. A systematic approach to concrete curing and the maintenance of building structures as a whole with the vertical division of a high-rise building into four temperature zones led to a reducing the probability of thermal cracks appearance.Conclusions. According to the results of the study, the proposed complex of technological solutions concerning compositions and properties of concrete mixtures and concretes, the technology of concreting, as well as the methods of heating and curing the concrete of structures at the various stages of their erection ensures thermal resistance to cracks at the early stage of concrete hardening, as well as the high quality and assigned rates of construction.
{"title":"A technology of erecting high-rise building frame structures using B60-B100 classes high-strength concretes","authors":"S. S. Kaprielov, A. Sheynfeld, Al-Omais Dzhalal, A. S. Zaitsev, R. Amirov","doi":"10.37538/2224-9494-2022-2(33)-106-121","DOIUrl":"https://doi.org/10.37538/2224-9494-2022-2(33)-106-121","url":null,"abstract":"Introduction. The article presents a technology of erecting of high-rise building's frame structures made of B60-B100 classes high-strength concretes. This technology includes a complex of processes and considers a number of special features, the most significant of which are connected with the specific character of high-strength concretes and concreting climatic conditions.Aim. To determine the main requirements for the technology of concreting and parameters of curing the monolithic structures of high-rise buildings made of B60-B100 classes high-strength concretes, including at winter periods, at the various stages of their erection.Methods and materials. Studies were carried out on the effect of hardening temperature variations from +5 to +50 °С on the hardening kinetics of B60, B80, and B100 classes concretes. Based on the 15-year experience of the “Moscow-City” construction, the mix proportions of high-strength concretes were optimized, as well as the main technological parameters of concreting and curing the frame structures located at an altitude of up to 370 m were analyzed and summarized.Results. The mix proportions of B60-B100 classes concretes of high-workability and self-compacting mixtures with a cement consumption of 350–480 kg/m3 was optimized using standard materials and MB-type organomineral modifiers. The performed study revealed a regularity between the strength and the temperature-temporal parameter of concrete curing, which is applicable for a preliminary assessment of strength characteristics in high-strength concrete structures on the basis of their temperature measurement results. A systematic approach to concrete curing and the maintenance of building structures as a whole with the vertical division of a high-rise building into four temperature zones led to a reducing the probability of thermal cracks appearance.Conclusions. According to the results of the study, the proposed complex of technological solutions concerning compositions and properties of concrete mixtures and concretes, the technology of concreting, as well as the methods of heating and curing the concrete of structures at the various stages of their erection ensures thermal resistance to cracks at the early stage of concrete hardening, as well as the high quality and assigned rates of construction. ","PeriodicalId":169749,"journal":{"name":"Bulletin of Science and Research Center of Construction","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116277751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-08DOI: 10.37538/2224-9494-2022-2(33)-63-73
Z. Beppaev, L. Astvatsaturova, S. A. Kolodyazhny, S. A. Vernygora, V. V. Lopatinsky
Introduction. Construction enterprises can adversely affect the environment during the extraction of natural raw materials, as well as during the reconstruction, overhaul, and demolition of buildings. The manufacturing of construction materials, the actual erection, and maintenance of various buildings and structures comprise highly material- and energy-intensive processes characterized by waste generation, which need to be disposed. In developed countries, recycling wastes as a commercial commodity represents the preferable way of recovering concrete, reinforced concrete, and masonry (brick) waste. In this regard, the disposal of construction waste (including waste from sand-lime brick and brickwork) is becoming increasingly important.Aim. In this work, the grain-size distribution, strength, and bulk density of recycled crushed aggregate from crushed sand-lime bricks (open stone mix) and brickwork (containing mortar) were determined and compared, and the prospects of its use as aggregates in the production of general-purpose concrete were identified.Materials and methods. Recycled crushed aggregate from crushed sand-lime bricks (open stone mix) and brickwork (containing mortar) was used for the studies. The recycled crushed aggregate was tested as per GOST 8269.0-97, its characteristics were evaluated as per GOST 8267-93.Results. This work shows the correlation between the bulk density, grain-size distribution, and crushing capacity of recycled crushed aggregate produced by crushing fragments of brickwork (containing mortar) and sand-lime bricks (open stone mix).Conclusions. It is shown that recycled crushed aggregate obtained by crushing fragments of brickwork (containing mortar) and sand-lime bricks (open stone mix) are suitable (along with crushed stone from sedimentary and metamorphic rocks) for use as a coarse aggregate in the production of general-purpose concrete. It is shown that it is necessary to carry out comprehensive experimental work in order to develop a new GOST, which will improve the recycling of sand-lime bricks, as well as structures and products based on them following the end of their operation lifetime, and allow high-quality ready-to-use construction material to be obtained.
{"title":"Determination of standard characteristics of recycled crushed aggregate from crushed sand-lime brick and prospects of its application","authors":"Z. Beppaev, L. Astvatsaturova, S. A. Kolodyazhny, S. A. Vernygora, V. V. Lopatinsky","doi":"10.37538/2224-9494-2022-2(33)-63-73","DOIUrl":"https://doi.org/10.37538/2224-9494-2022-2(33)-63-73","url":null,"abstract":"Introduction. Construction enterprises can adversely affect the environment during the extraction of natural raw materials, as well as during the reconstruction, overhaul, and demolition of buildings. The manufacturing of construction materials, the actual erection, and maintenance of various buildings and structures comprise highly material- and energy-intensive processes characterized by waste generation, which need to be disposed. In developed countries, recycling wastes as a commercial commodity represents the preferable way of recovering concrete, reinforced concrete, and masonry (brick) waste. In this regard, the disposal of construction waste (including waste from sand-lime brick and brickwork) is becoming increasingly important.Aim. In this work, the grain-size distribution, strength, and bulk density of recycled crushed aggregate from crushed sand-lime bricks (open stone mix) and brickwork (containing mortar) were determined and compared, and the prospects of its use as aggregates in the production of general-purpose concrete were identified.Materials and methods. Recycled crushed aggregate from crushed sand-lime bricks (open stone mix) and brickwork (containing mortar) was used for the studies. The recycled crushed aggregate was tested as per GOST 8269.0-97, its characteristics were evaluated as per GOST 8267-93.Results. This work shows the correlation between the bulk density, grain-size distribution, and crushing capacity of recycled crushed aggregate produced by crushing fragments of brickwork (containing mortar) and sand-lime bricks (open stone mix).Conclusions. It is shown that recycled crushed aggregate obtained by crushing fragments of brickwork (containing mortar) and sand-lime bricks (open stone mix) are suitable (along with crushed stone from sedimentary and metamorphic rocks) for use as a coarse aggregate in the production of general-purpose concrete. It is shown that it is necessary to carry out comprehensive experimental work in order to develop a new GOST, which will improve the recycling of sand-lime bricks, as well as structures and products based on them following the end of their operation lifetime, and allow high-quality ready-to-use construction material to be obtained. ","PeriodicalId":169749,"journal":{"name":"Bulletin of Science and Research Center of Construction","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122119727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-08DOI: 10.37538/2224-9494-2022-2(33)-74-82
A. Buchkin, K. Kudyakov, S. D. Epikhin, S. Khlebnikov
Introduction. The technology of connecting precast reinforced concrete piles using pile joints is a promissing method in construction. According to some previous studies, the use of Leimet ABB+ pile joints provides for a significant reduction in material and labor intensity, as well as the time required for connecting the piles under sufficiently high strength and durability. Currently, the application of this technology is limited due to the insufficient knowledge of mechanical characteristics of pin connections. This article presents the results of strength tests of Leimet ABB+ pile joints for recast reinforced concrete piles.Aim. Experimental testing of the strength parameters of Leimet ABB+ pile joints under compression, tensile, transverse shear, and bending.Methods and materials. Experiments were performed using test samples represented by two fragments of recast reinforced concrete piles of the 1.011.1-10 standard, which were joined by a 4-lock Leimet ABB+ 400 pile joint. Loading tests of the samples were carried out in accordance with the GOST 8829-2018.Results. The qualitative and quantitative destruction parameters of the test samples were obtained. The destruction of all the test samples occurred along the concrete body of piles with no signs of destruction of the metal pin connection. In addition, no signs of concrete indents in the area of the pin connection were observed.Conclusions. Leimet ABB+ 400 pile joints were concluded to be of the uniform strength to the concrete pile body under the considered conditions. The test results of the pile joint strength are applicable when developing design projects.
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