Pub Date : 2023-08-24DOI: 10.31675/1607-1859-2023-25-4-161-175
Г.А. Непомнящев, М.М. Титов, G. Nepomnyashchev, M. Titov
Due to the need of the construction industry for the intensification of various technological processes, it is necessary to reduce the time of specifying concrete parameters such as design, stripping, critical strength. It is relevant to develop technologies allowing to accelerate the process of setting the required strength parameters of concrete structures and increase them at specific time intervals.Activation technologies of cement suspensions, concretes and mortars are analyzed. The most promising and less studied directions in the strength properties improvement are identified.The aim of this work is to identify the physical impact on cement-containing materials to accelerate the strength gain in cement paste. A combination of several methods of electrophysical processing is used to develop the method of strength improvement and gain in cement paste. Electrophysical processing is based on electric polarization, electro-hydraulic shock and ultrasonic treatment.The paper proposes the most optimum mode for the water-cement suspension treatment, which provides a multiple increase in the strength gain in the first seven days, compared to the untreated suspension.The proposed electrophysical processing significantly improves the strength of hydrated cement and the best water-cement ratio is obtained to highly increase the concrete strength after seven days.
{"title":"Increasing cement strength properties with electrophysical processing of water-cement suspension","authors":"Г.А. Непомнящев, М.М. Титов, G. Nepomnyashchev, M. Titov","doi":"10.31675/1607-1859-2023-25-4-161-175","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-161-175","url":null,"abstract":"Due to the need of the construction industry for the intensification of various technological processes, it is necessary to reduce the time of specifying concrete parameters such as design, stripping, critical strength. It is relevant to develop technologies allowing to accelerate the process of setting the required strength parameters of concrete structures and increase them at specific time intervals.Activation technologies of cement suspensions, concretes and mortars are analyzed. The most promising and less studied directions in the strength properties improvement are identified.The aim of this work is to identify the physical impact on cement-containing materials to accelerate the strength gain in cement paste. A combination of several methods of electrophysical processing is used to develop the method of strength improvement and gain in cement paste. Electrophysical processing is based on electric polarization, electro-hydraulic shock and ultrasonic treatment.The paper proposes the most optimum mode for the water-cement suspension treatment, which provides a multiple increase in the strength gain in the first seven days, compared to the untreated suspension.The proposed electrophysical processing significantly improves the strength of hydrated cement and the best water-cement ratio is obtained to highly increase the concrete strength after seven days.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"38 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83207250","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 : 2023-08-24DOI: 10.31675/1607-1859-2023-25-4-211-225
Михаил Юрьевич Горский, Евгений Николаевич Симчук, Георгий Фаррухович Кадыров, Алексей Евгеньевич Симчук, Mikhail Y. Gorskii, E. N. Simchuk, G. F. Kadyrov, Aleksei E. Simchuk
The article presents the research results of the temperature influence on the flexural bowl on the road surface determined by falling weight deflectometer testing. The work relevance is conditioned by the high temperature effect of asphalt concrete on test results and the need to take it into account by bringing the results obtained at the actual temperature to a comparable form with the design data, when performing diagnostics of operating highways.Experiments identify the temperature factors that have an impact on the flexural bowl parameters. Temperature dependences are suggested for the flexural bowl on different road surfaces. A falling weight deflectometer is used to simulate the load produced by a moving truck, equipped with deflection meters located at the load center and various distances from it. Together with flexure bowl measurements, the temperatures of air, pavement and asphalt concrete at various depth is determined and dependences of these parameters are plotted.The paper identifies factors that have the greatest influence on the flexural bowl parameters. The results make it possible to bring flexural bowls into a form comparable with design values and subsequently use them to determine the overall bearing capacity of the pavement as well as to assess the condition of individual structural layers, thereby increasing the reliability of repair measures.
{"title":"Temperature effect on flexural bowl determined by falling weight deflectometer testing","authors":"Михаил Юрьевич Горский, Евгений Николаевич Симчук, Георгий Фаррухович Кадыров, Алексей Евгеньевич Симчук, Mikhail Y. Gorskii, E. N. Simchuk, G. F. Kadyrov, Aleksei E. Simchuk","doi":"10.31675/1607-1859-2023-25-4-211-225","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-211-225","url":null,"abstract":"The article presents the research results of the temperature influence on the flexural bowl on the road surface determined by falling weight deflectometer testing. The work relevance is conditioned by the high temperature effect of asphalt concrete on test results and the need to take it into account by bringing the results obtained at the actual temperature to a comparable form with the design data, when performing diagnostics of operating highways.Experiments identify the temperature factors that have an impact on the flexural bowl parameters. Temperature dependences are suggested for the flexural bowl on different road surfaces. A falling weight deflectometer is used to simulate the load produced by a moving truck, equipped with deflection meters located at the load center and various distances from it. Together with flexure bowl measurements, the temperatures of air, pavement and asphalt concrete at various depth is determined and dependences of these parameters are plotted.The paper identifies factors that have the greatest influence on the flexural bowl parameters. The results make it possible to bring flexural bowls into a form comparable with design values and subsequently use them to determine the overall bearing capacity of the pavement as well as to assess the condition of individual structural layers, thereby increasing the reliability of repair measures.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"22 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87264097","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 : 2023-08-24DOI: 10.31675/1607-1859-2023-25-4-143-160
Анатолий Васильевич Мананков, Валентин Михайлович Яковлев, Александр Андреевич Локтюшин, Евгений Яковлевич Горюхин, A. V. Manankov, Valentin M. Yakovlev, Aleksandr A. Loktyushin, Evgeniy Ya. Gorukhin
Silicate materials traditionally occupy an important place in materials science, despite the ever-changing demands. The improvement of materials requires the development of theory. The extensive experience accumulated by technical and experimental mineralogy does not always agree with traditional ideas and, sometimes, does not find an explanation in them at all. Such a situation arises in trying to describe the anomalously high kinetic parameters of diffusion and crystallization in glass and ceramics. The search for a solution to the problem leads to the use of the most general laws of natural science, the theory of oscillations and waves. Under the conditions of nonequilibrium crystallization in artificial silicate systems, the mechanism of spinodal decomposition is found, which is later confirmed in volcanic glasses of the Earth and Moon as well as in tektites. The proposed model of spatially closed dynamic structures takes into account the kinetics of phase transformations, when the formation of segregation products (molecular clusters) and bonds between them is of a resonant nature. As a result, a new class of multifunctional materials with an unusual combination of physical and chemical properties is created. Synthetic metasilicates masters about three dozen new technological applications in medicine (surgery, dentistry), household production, and aerospace equipment, materials science (modifying additives in ceramics, polyethylene, linoleum, asphalt), heatand wear-resistant lining, gold and slag pipelines. The economic efficiency of glass ceramics is shown on the example of the Federal Project The Northern Latitudinal Railway.
{"title":"New opportunities of multifunctional materials","authors":"Анатолий Васильевич Мананков, Валентин Михайлович Яковлев, Александр Андреевич Локтюшин, Евгений Яковлевич Горюхин, A. V. Manankov, Valentin M. Yakovlev, Aleksandr A. Loktyushin, Evgeniy Ya. Gorukhin","doi":"10.31675/1607-1859-2023-25-4-143-160","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-143-160","url":null,"abstract":"Silicate materials traditionally occupy an important place in materials science, despite the ever-changing demands. The improvement of materials requires the development of theory. The extensive experience accumulated by technical and experimental mineralogy does not always agree with traditional ideas and, sometimes, does not find an explanation in them at all. Such a situation arises in trying to describe the anomalously high kinetic parameters of diffusion and crystallization in glass and ceramics. The search for a solution to the problem leads to the use of the most general laws of natural science, the theory of oscillations and waves. Under the conditions of nonequilibrium crystallization in artificial silicate systems, the mechanism of spinodal decomposition is found, which is later confirmed in volcanic glasses of the Earth and Moon as well as in tektites. The proposed model of spatially closed dynamic structures takes into account the kinetics of phase transformations, when the formation of segregation products (molecular clusters) and bonds between them is of a resonant nature. As a result, a new class of multifunctional materials with an unusual combination of physical and chemical properties is created. Synthetic metasilicates masters about three dozen new technological applications in medicine (surgery, dentistry), household production, and aerospace equipment, materials science (modifying additives in ceramics, polyethylene, linoleum, asphalt), heatand wear-resistant lining, gold and slag pipelines. The economic efficiency of glass ceramics is shown on the example of the Federal Project The Northern Latitudinal Railway.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"9 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89535686","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 : 2023-08-24DOI: 10.31675/1607-1859-2023-25-4-199-210
В.М. Картопольцев, А.В. Картопольцев, Алексей Александрович Алексеев, V. Kartopoltsev, Audrey V. Kartopoltsev, А.А. Alekseev
The requirements for the plate-bearing test of bore piles are determined by technical regulations for the construction of pile foundations for bridge abutments. There is no information about the plate-bearing test reliability in the literature. Bridge pile foundations as bridge elements relate to strategic and economically responsible objects of the transport infrastructure in the Russian Federation and must have a high reliability level at the design stage and operation.Purpose: Practical application of the reliability theory for plate-bearing tests to ensure control for construction and economic expenditures.Approach: The probabilistic approach in providing plate-bearing test reliability is conditioned by a random nature of the stress-strain state of soil under the bore pile tip and nonfailure operating probability.Research findings: Probability density functions allow restrictions such as loading stages and time without the reliability reduction of plate-bearing tests and the possibility of using the experimental load–soil settlement relation to substantiate the program requirements and economic feasibility of works.
{"title":"Reliability of plate-bearing tests of pile foundations for bridge abutments","authors":"В.М. Картопольцев, А.В. Картопольцев, Алексей Александрович Алексеев, V. Kartopoltsev, Audrey V. Kartopoltsev, А.А. Alekseev","doi":"10.31675/1607-1859-2023-25-4-199-210","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-199-210","url":null,"abstract":"The requirements for the plate-bearing test of bore piles are determined by technical regulations for the construction of pile foundations for bridge abutments. There is no information about the plate-bearing test reliability in the literature. Bridge pile foundations as bridge elements relate to strategic and economically responsible objects of the transport infrastructure in the Russian Federation and must have a high reliability level at the design stage and operation.Purpose: Practical application of the reliability theory for plate-bearing tests to ensure control for construction and economic expenditures.Approach: The probabilistic approach in providing plate-bearing test reliability is conditioned by a random nature of the stress-strain state of soil under the bore pile tip and nonfailure operating probability.Research findings: Probability density functions allow restrictions such as loading stages and time without the reliability reduction of plate-bearing tests and the possibility of using the experimental load–soil settlement relation to substantiate the program requirements and economic feasibility of works.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"236 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87627076","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 : 2023-08-24DOI: 10.31675/1607-1859-2023-25-4-189-198
Сергей Васильевич Ющубе, Александр Александрович, Тарасов Артем Сергеевич, Устюгов, А.А. Тарасов, А.С. Устюгов, S. V. Yushchube, Aleksandr A. Tarasov, A. S. Ustyugov
The paper studies the pile penetration force in engineering and geological conditions of Tomsk. The pile penetration method allows piles to be penetrated in urban conditions with a large number of historical buildings, which makes this work extremely relevant for Tomsk and other cities.The paper presents experimental data and theoretical calculations of the pile penetration in various districts of Tomsk. Theoretical calculations are based on several regulatory documents. Research results allow assessing the applicability of the proposed methods to engineering and geological conditions of Tomsk as well as identifying factors reducing the reliability this method. Recommendations are given for selecting methods to determine the pile penetration force, depending on the soil conditions at the construction site.
{"title":"Comparison of experimental pile penetration force and calculated by regulatory documents","authors":"Сергей Васильевич Ющубе, Александр Александрович, Тарасов Артем Сергеевич, Устюгов, А.А. Тарасов, А.С. Устюгов, S. V. Yushchube, Aleksandr A. Tarasov, A. S. Ustyugov","doi":"10.31675/1607-1859-2023-25-4-189-198","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-189-198","url":null,"abstract":"The paper studies the pile penetration force in engineering and geological conditions of Tomsk. The pile penetration method allows piles to be penetrated in urban conditions with a large number of historical buildings, which makes this work extremely relevant for Tomsk and other cities.The paper presents experimental data and theoretical calculations of the pile penetration in various districts of Tomsk. Theoretical calculations are based on several regulatory documents. Research results allow assessing the applicability of the proposed methods to engineering and geological conditions of Tomsk as well as identifying factors reducing the reliability this method. Recommendations are given for selecting methods to determine the pile penetration force, depending on the soil conditions at the construction site.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"14 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77902185","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 : 2023-08-24DOI: 10.31675/1607-1859-2023-25-4-176-188
S. V. Yushchube, I. Podshivalov, A. A. Tarasov, A. V. Burmin, V. I. Ustyuzhanin
Purpose: The aim of the work is to determine the bearing capacity of walls and columns of the building during significant movement of its natural-stone foundation on unstable soil.Methodology: The finite-element model of stress-strain state is developed by using Ing+2021 MicroFe software package.Research findings: During 168 years of the long-term service since 1854, the negative effect from soil frost-thawing, frost heave of the rubble foundation, and geotechnical influence of the Tom river, provided a significant fluctuation of the water level during low-water and flood periods. The foundation was considerably settled, that disturbed the spatial rigidity of the historic building.Practical implications: The obtained results can be used to develop recommendations for ensuring necessary spatial rigidity of the brick building via the reinforcement of exterior walls with tensioned steel ties on inter-floor and attic ceilings.
{"title":"The influence of nonuniform movement of rubble foundation on bearing capacity of brick walls of a historic building","authors":"S. V. Yushchube, I. Podshivalov, A. A. Tarasov, A. V. Burmin, V. I. Ustyuzhanin","doi":"10.31675/1607-1859-2023-25-4-176-188","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-176-188","url":null,"abstract":"Purpose: The aim of the work is to determine the bearing capacity of walls and columns of the building during significant movement of its natural-stone foundation on unstable soil.Methodology: The finite-element model of stress-strain state is developed by using Ing+2021 MicroFe software package.Research findings: During 168 years of the long-term service since 1854, the negative effect from soil frost-thawing, frost heave of the rubble foundation, and geotechnical influence of the Tom river, provided a significant fluctuation of the water level during low-water and flood periods. The foundation was considerably settled, that disturbed the spatial rigidity of the historic building.Practical implications: The obtained results can be used to develop recommendations for ensuring necessary spatial rigidity of the brick building via the reinforcement of exterior walls with tensioned steel ties on inter-floor and attic ceilings.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"39 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75649353","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 : 2023-08-24DOI: 10.31675/1607-1859-2023-25-4-129-142
A. A. Krutilin, T. V. Krapchetova, N. A. Inkova, O. K. Pakhomova
Factors affecting the clinker strength are of great interest. The implementation of the dry process attracts attention to the homogeneity of the chemical and mineralogical composition of raw mixes.Purpose: One of the main factors affecting the clinker hydraulic activity is the homogeneity of its chemical and mineralogical compositions. The aim of this work is to study clinkers prepared by different production methods in furnaces using wet and dry processes.Methodology: X-ray fluorescence analysis of chemical composition of mixes; X-ray powder diffraction analysis of clinker mineralogical composition; petrographic analysis of clinker microstructure;Research findings: The clinker structure obtained in drying furnaces is glomeroblastic. Minerals mostly generate clusters alternating with each other. Clinker crystallization is mediumcrystalline, unequigranular. Alite and belite can form both individual grains and aggregates.Research findings: The chemical composition heterogeneity of raw mixes directly affects the clinker mineralogical composition of microstructure, that has a significant impact on its hydraulic activity.
{"title":"The influence of homogeneity of chemical and mineralogical composition of raw mixes on strength properties of Portland clinker","authors":"A. A. Krutilin, T. V. Krapchetova, N. A. Inkova, O. K. Pakhomova","doi":"10.31675/1607-1859-2023-25-4-129-142","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-129-142","url":null,"abstract":"Factors affecting the clinker strength are of great interest. The implementation of the dry process attracts attention to the homogeneity of the chemical and mineralogical composition of raw mixes.Purpose: One of the main factors affecting the clinker hydraulic activity is the homogeneity of its chemical and mineralogical compositions. The aim of this work is to study clinkers prepared by different production methods in furnaces using wet and dry processes.Methodology: X-ray fluorescence analysis of chemical composition of mixes; X-ray powder diffraction analysis of clinker mineralogical composition; petrographic analysis of clinker microstructure;Research findings: The clinker structure obtained in drying furnaces is glomeroblastic. Minerals mostly generate clusters alternating with each other. Clinker crystallization is mediumcrystalline, unequigranular. Alite and belite can form both individual grains and aggregates.Research findings: The chemical composition heterogeneity of raw mixes directly affects the clinker mineralogical composition of microstructure, that has a significant impact on its hydraulic activity.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"4 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87531366","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 : 2023-08-24DOI: 10.31675/1607-1859-2023-25-4-116-128
Денис Александрович Тарасов, Denis A. Tarasov
Purpose: The aim of this work is to develop a method to determine the best geometrical parameters of the flexural thread cross-section providing the lowest potential energy of deformation, thereby meeting the requirements for the minimum weight based on strength and rigidity limitations on the designed element.Methodology/approach: The problem of calculating the best parameters is reduced to nonlinear mathematical programming using the energy criterion. The latter provides to gain the minimum potential energy of deformation of the designed element.Research findings: The proposed methodology allows evaluating the results obtained. The numerical experiment determines the optimum cross-section geometry of flexural thread. The spread in values between proposed methodology and finite element method are insignificant.Practical implications: The proposed method provides the solution of inverse problems in a geometrically nonlinear formulation, including a search for optimum geometrical parameters of elements that combine the operation of beams and flexural thread. The proposed method can be used at the design stage of large-span shells of buildings.
{"title":"Cross-section geometry optimization of flexural thread using energy criterion","authors":"Денис Александрович Тарасов, Denis A. Tarasov","doi":"10.31675/1607-1859-2023-25-4-116-128","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-116-128","url":null,"abstract":"Purpose: The aim of this work is to develop a method to determine the best geometrical parameters of the flexural thread cross-section providing the lowest potential energy of deformation, thereby meeting the requirements for the minimum weight based on strength and rigidity limitations on the designed element.Methodology/approach: The problem of calculating the best parameters is reduced to nonlinear mathematical programming using the energy criterion. The latter provides to gain the minimum potential energy of deformation of the designed element.Research findings: The proposed methodology allows evaluating the results obtained. The numerical experiment determines the optimum cross-section geometry of flexural thread. The spread in values between proposed methodology and finite element method are insignificant.Practical implications: The proposed method provides the solution of inverse problems in a geometrically nonlinear formulation, including a search for optimum geometrical parameters of elements that combine the operation of beams and flexural thread. The proposed method can be used at the design stage of large-span shells of buildings.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"41 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77912432","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 : 2023-08-23DOI: 10.31675/1607-1859-2023-25-4-98-115
D. V. Konin
Steel-reinforced concrete floors with prefabricated reinforced concrete slabs are industrial quickly erectable structures. The use of such structures makes it possible to reduce construction time, save metal, obtain efficient structures without beam projecting up to 20 m for loads produced by buildings and car parks. Codes and foreign norms do not include prefabricated reinforced concrete floor slabs in the operation of combined structures, as designers try to avoid complex connections (welding, bolts) during construction. Of obvious interest is the inclusion of precast slabs in the operation of combined steel and reinforced concrete beam as well as grouted joints between steel and slabs in the absence of additional anchors and connections.Experimental results of structural models and 6×10 m floors with precast slabs are considered to identify the concrete shear. The effective shear deformation up to 0.5 mm is detected even without additional anchors. Simplest anchors significantly increase the joint operation of cast concrete and steel profile. The operation mechanism is determined for steel-concrete and steelconcrete-anchor contact zones, and respective diagrams are plotted for numerical calculations.Floor testing shows that the use of the simplest joining, cast reinforced concrete combining steel and precast elements involves precast slabs at a distance from the beam axis of at least two thicknesses of the floor for two different ways of the beam support.Numerical modelling, including the contact zone operation, shows good agreement with the experimental data. It is recommended to clarify the width of compressed concrete flange in normative documents for the structural analysis.
{"title":"Stress and shear of steel reinforced floors with prefabricated units and steel beams","authors":"D. V. Konin","doi":"10.31675/1607-1859-2023-25-4-98-115","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-98-115","url":null,"abstract":"Steel-reinforced concrete floors with prefabricated reinforced concrete slabs are industrial quickly erectable structures. The use of such structures makes it possible to reduce construction time, save metal, obtain efficient structures without beam projecting up to 20 m for loads produced by buildings and car parks. Codes and foreign norms do not include prefabricated reinforced concrete floor slabs in the operation of combined structures, as designers try to avoid complex connections (welding, bolts) during construction. Of obvious interest is the inclusion of precast slabs in the operation of combined steel and reinforced concrete beam as well as grouted joints between steel and slabs in the absence of additional anchors and connections.Experimental results of structural models and 6×10 m floors with precast slabs are considered to identify the concrete shear. The effective shear deformation up to 0.5 mm is detected even without additional anchors. Simplest anchors significantly increase the joint operation of cast concrete and steel profile. The operation mechanism is determined for steel-concrete and steelconcrete-anchor contact zones, and respective diagrams are plotted for numerical calculations.Floor testing shows that the use of the simplest joining, cast reinforced concrete combining steel and precast elements involves precast slabs at a distance from the beam axis of at least two thicknesses of the floor for two different ways of the beam support.Numerical modelling, including the contact zone operation, shows good agreement with the experimental data. It is recommended to clarify the width of compressed concrete flange in normative documents for the structural analysis.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"12 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75348595","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 : 2023-08-23DOI: 10.31675/1607-1859-2023-25-4-71-83
А.А. Кутуков, Е.Н. Колокольцева, Л.С. Романова, A. A. Kutukov, E. N. Kolokoltseva, L. Romanova
The relevance of the study is due to the problem of preservation of historical and cultural heritage of Russia and the city of Tomsk in particular.Purpose: The aim of the paper is to draw attention to the disturbance of the structural integrity of architectural monuments such as transport vibrations and stray earth currents.Methodology/approach: Field studies of the architectural monument of the Church of St. Alexander Nevsky in Tomsk; the analysis of the city plan in the area of Gertsen and Sovetskaya Streets; measures proposed for the monument protection from negative influences of the urban environment. Originality: The paper proposes protection measures for the Church of St. Alexander Nevsky of the regional importance from vibrations and stray earth currents generated by trams moving in the vicinity of the Church.Practical implications: Recommendations are given for eliminating the negative impact of transport vibrations on architectural monuments on the example of the Church of St. Alexander Nevsky in Tomsk.
{"title":"Engineering problems of restoration. Protection of historic buildings from negative environmental impact","authors":"А.А. Кутуков, Е.Н. Колокольцева, Л.С. Романова, A. A. Kutukov, E. N. Kolokoltseva, L. Romanova","doi":"10.31675/1607-1859-2023-25-4-71-83","DOIUrl":"https://doi.org/10.31675/1607-1859-2023-25-4-71-83","url":null,"abstract":"The relevance of the study is due to the problem of preservation of historical and cultural heritage of Russia and the city of Tomsk in particular.Purpose: The aim of the paper is to draw attention to the disturbance of the structural integrity of architectural monuments such as transport vibrations and stray earth currents.Methodology/approach: Field studies of the architectural monument of the Church of St. Alexander Nevsky in Tomsk; the analysis of the city plan in the area of Gertsen and Sovetskaya Streets; measures proposed for the monument protection from negative influences of the urban environment. Originality: The paper proposes protection measures for the Church of St. Alexander Nevsky of the regional importance from vibrations and stray earth currents generated by trams moving in the vicinity of the Church.Practical implications: Recommendations are given for eliminating the negative impact of transport vibrations on architectural monuments on the example of the Church of St. Alexander Nevsky in Tomsk.","PeriodicalId":45402,"journal":{"name":"Tomsk State University Journal","volume":"6 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79159926","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}
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