Pub Date : 2021-08-12DOI: 10.34031/2618-7183-2021-4-3-54-60
S. Kuznecov, A. A. Shemali
the problem of protecting buildings and structures from vibrations of natural and artificial nature is im-portant for modern construction. One of such modern methods of protection is seismic pads. The purpose of this work was to study the effect of adding a layer of granular metamaterial under a slab foundation on the vibration of a building under the influence of seismic shear waves (S-waves). To achieve this objective, the finite element method (FEM) was used in combination with Cam-Clay models. The FE model consists of a ten-story superstructure rested on the slab foundation, under which there is a layer of granular metamateri-als. 16 models were created taking into account changes in the values of these parameters (pad thickness; density; cohesion; critical state strength parameter (M); Young's modulus-Poisson's ratio). The dynamic analysis performed using the software package Abaqus/CAE showed the effectiveness of granular met-amaterials in their ability to dissipate seismic energy and significantly reduce vibration transmitted from the ground to the building.
{"title":"MODIFIED CAM-CLAY MODELS FOR DYNAMIC ANALYSIS OF GRANULAR METAMATERIALS IN EARTHQUAKE ENGINEERING","authors":"S. Kuznecov, A. A. Shemali","doi":"10.34031/2618-7183-2021-4-3-54-60","DOIUrl":"https://doi.org/10.34031/2618-7183-2021-4-3-54-60","url":null,"abstract":"the problem of protecting buildings and structures from vibrations of natural and artificial nature is im-portant for modern construction. One of such modern methods of protection is seismic pads. The purpose of this work was to study the effect of adding a layer of granular metamaterial under a slab foundation on the vibration of a building under the influence of seismic shear waves (S-waves). To achieve this objective, the finite element method (FEM) was used in combination with Cam-Clay models. The FE model consists of a ten-story superstructure rested on the slab foundation, under which there is a layer of granular metamateri-als. 16 models were created taking into account changes in the values of these parameters (pad thickness; density; cohesion; critical state strength parameter (M); Young's modulus-Poisson's ratio). The dynamic analysis performed using the software package Abaqus/CAE showed the effectiveness of granular met-amaterials in their ability to dissipate seismic energy and significantly reduce vibration transmitted from the ground to the building.","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"500 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116191308","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 : 2021-08-12DOI: 10.34031/2618-7183-2021-4-3-23-40
S. Zhuykov
the study of the complex influence of weather and climatic factors and their variability on the needs of en-ergy and exergy when creating thermal comfort in a house with various engineering and architectural charac-teristics is carried out. It is confirmed that even for houses with relatively low thermal characteristics built in accordance with regulatory documents, the role of solar radiation in the formation of the heat balance, espe-cially at the beginning and end of the heating season, is important. Studies showed that due to the combined influence of external meteorological factors, with the improvement of the thermal characteristics of houses, the correlation between the energy demand for creating a favorable microclimate and the outdoor air tem-perature significantly worsens. It is determined that in this case, the value of the approximation reliability decreases from 1 (with a linear dependence) to 0.55 and lower (with the maximum possible improved ther-mal characteristics of the house today). This position significantly corrects the operating modes and charac-teristics of the ST. In particular, this makes it necessary to improve the automatic control system of ST. And this, in turn, increases the investment component of the system. A method was developed for calculating exergy needs to create thermal comfort inside the house by taking into account, using the probability theory, the influence of the random nature of meteorological factors within the heating period, on the basis of which, in the conditions of the region, it is shown and calculated that when determining the seasonal exergy needs for the heat supply of the house, the use of a stationary approach leads to an underestimation of the results by 12...28% compared to the dynamic approach
{"title":"EXERGETIC ANALYSIS OF A BUILDING AS A KEY ELEMENT OF A HEAT SUPPLY SYSTEM","authors":"S. Zhuykov","doi":"10.34031/2618-7183-2021-4-3-23-40","DOIUrl":"https://doi.org/10.34031/2618-7183-2021-4-3-23-40","url":null,"abstract":"the study of the complex influence of weather and climatic factors and their variability on the needs of en-ergy and exergy when creating thermal comfort in a house with various engineering and architectural charac-teristics is carried out. It is confirmed that even for houses with relatively low thermal characteristics built in accordance with regulatory documents, the role of solar radiation in the formation of the heat balance, espe-cially at the beginning and end of the heating season, is important. Studies showed that due to the combined influence of external meteorological factors, with the improvement of the thermal characteristics of houses, the correlation between the energy demand for creating a favorable microclimate and the outdoor air tem-perature significantly worsens. It is determined that in this case, the value of the approximation reliability decreases from 1 (with a linear dependence) to 0.55 and lower (with the maximum possible improved ther-mal characteristics of the house today). This position significantly corrects the operating modes and charac-teristics of the ST. In particular, this makes it necessary to improve the automatic control system of ST. And this, in turn, increases the investment component of the system. A method was developed for calculating exergy needs to create thermal comfort inside the house by taking into account, using the probability theory, the influence of the random nature of meteorological factors within the heating period, on the basis of which, in the conditions of the region, it is shown and calculated that when determining the seasonal exergy needs for the heat supply of the house, the use of a stationary approach leads to an underestimation of the results by 12...28% compared to the dynamic approach","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126689811","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 : 2021-08-12DOI: 10.34031/2618-7183-2021-4-3-5-22
S. Plehanova, N. Vingradova
the possibility of obtaining structural and thermal insulation foam concrete of non-autoclave hardening with improved construction and technical characteristics for the device of a thermal insulation layer in the con-struction of road pavement due to three-dimensional dispersed reinforcement with polypropylene fiber is theoretically justified and experimentally confirmed. Based on the results of studies of the influence of technological factors on the properties of foam concrete, the optimal content (up to 0.25% of the cement mass) and the length (12 mm) of reinforcing polypropylene fibers have been established, which allows ob-taining high strength indicators of dispersed-reinforced cement stone for bending (an increase of 12-20%) and compression (an increase of 6-12%) compared with non-reinforced cement stone of non-autoclaved foam concrete. The analysis of the process of structure formation of dispersed reinforced foam concrete from the standpoint of a systematic approach based on multifactorial polynomial models of the influence of the ratio of filler and binder, as well as the number of dispersed reinforcing fibers, which is determined by the optimal conditions for the distribution of solid and gas phases, as well as the reinforcement of adjacent interstitial partitions of foam concrete, linking them into one asociate, which ensures the joint work of the material under various external influences. A method was developed to increase the durability of the road surface and eliminate the influence of the frost heaving effect on the quality of the road surface by intro-ducing the necessary amount of effective thermal insulation layer into the road surface design. The analysis of the regularity of the heat transfer process in the soil mass of the roadbed and multilayer road pavement is carried out. Based on the analysis, the values of the necessary resistance to heat transfer of road pavement for the natural and climatic regions of the country are determined and a method for calculating the value of the thermal insulation (frost-proof) layer of road pavement is proposed. A method was developed for calcu-lating the value of the thermal insulation layer using monolithic fibre foam concrete and a nomogram to de-termine the required value of the thermal insulation layer made of monolithic non-autoclaved structural and thermal insulation fibre foam concrete of classes D600-D1000.
{"title":"OBTAINING A THERMAL INSULATION LAYER FROM MONOLITHIC NON-AUTOCLAVED STRUCTURAL AND THERMAL INSULATION FIBRE FOAM CONCRETE","authors":"S. Plehanova, N. Vingradova","doi":"10.34031/2618-7183-2021-4-3-5-22","DOIUrl":"https://doi.org/10.34031/2618-7183-2021-4-3-5-22","url":null,"abstract":"the possibility of obtaining structural and thermal insulation foam concrete of non-autoclave hardening with improved construction and technical characteristics for the device of a thermal insulation layer in the con-struction of road pavement due to three-dimensional dispersed reinforcement with polypropylene fiber is theoretically justified and experimentally confirmed. Based on the results of studies of the influence of technological factors on the properties of foam concrete, the optimal content (up to 0.25% of the cement mass) and the length (12 mm) of reinforcing polypropylene fibers have been established, which allows ob-taining high strength indicators of dispersed-reinforced cement stone for bending (an increase of 12-20%) and compression (an increase of 6-12%) compared with non-reinforced cement stone of non-autoclaved foam concrete. The analysis of the process of structure formation of dispersed reinforced foam concrete from the standpoint of a systematic approach based on multifactorial polynomial models of the influence of the ratio of filler and binder, as well as the number of dispersed reinforcing fibers, which is determined by the optimal conditions for the distribution of solid and gas phases, as well as the reinforcement of adjacent interstitial partitions of foam concrete, linking them into one asociate, which ensures the joint work of the material under various external influences. A method was developed to increase the durability of the road surface and eliminate the influence of the frost heaving effect on the quality of the road surface by intro-ducing the necessary amount of effective thermal insulation layer into the road surface design. The analysis of the regularity of the heat transfer process in the soil mass of the roadbed and multilayer road pavement is carried out. Based on the analysis, the values of the necessary resistance to heat transfer of road pavement for the natural and climatic regions of the country are determined and a method for calculating the value of the thermal insulation (frost-proof) layer of road pavement is proposed. A method was developed for calcu-lating the value of the thermal insulation layer using monolithic fibre foam concrete and a nomogram to de-termine the required value of the thermal insulation layer made of monolithic non-autoclaved structural and thermal insulation fibre foam concrete of classes D600-D1000.","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123250286","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 : 2021-08-12DOI: 10.34031/2618-7183-2021-4-3-41-53
V. Chepurnenko, K. Hashhozhev, S. Yazyev, A. Avakov
the article is devoted to a newly developed complex finite element that allows modeling concrete-filled steel tubular columns taking into account the compression of the concrete core from the steel tube, as well as ge-ometric nonlinearity. The derivation of the resolving equations, as well as expressions for the elements of the stiffness matrix, is based on the hypothesis of plane sections. The complex testing of the finite element was performed using the program code written by the authors in the MATLAB language and the ANSYS software, as well as the analysis of the effectiveness of the new FE in comparison with the classical methods of modeling CFST-columns in modern software systems. A significant decrease in the order of the system of FEM equations is demonstrated in comparison with the modeling of CFST-structures in a volumetric formu-lation in existing design complexes using SOLID elements for a concrete core with 3 degrees of freedom in each of the nodes, and SHELL elements for a steel tube with 6 degrees of freedom in each of the nodes, with a comparable accuracy in determining the stress-strain state. The behavior of steel and concrete in the presented work is assumed to be linearly elastic, however, the described calculation method can be generalized to the case of using nonlinear deformation models of materials.
{"title":"IMPROVING THE CALCULATION OF FLEXIBLE CFST-COLUMNS, TAKING INTO ACCOUNT STRESSES IN THE SECTION PLANES","authors":"V. Chepurnenko, K. Hashhozhev, S. Yazyev, A. Avakov","doi":"10.34031/2618-7183-2021-4-3-41-53","DOIUrl":"https://doi.org/10.34031/2618-7183-2021-4-3-41-53","url":null,"abstract":"the article is devoted to a newly developed complex finite element that allows modeling concrete-filled steel tubular columns taking into account the compression of the concrete core from the steel tube, as well as ge-ometric nonlinearity. The derivation of the resolving equations, as well as expressions for the elements of the stiffness matrix, is based on the hypothesis of plane sections. The complex testing of the finite element was performed using the program code written by the authors in the MATLAB language and the ANSYS software, as well as the analysis of the effectiveness of the new FE in comparison with the classical methods of modeling CFST-columns in modern software systems. A significant decrease in the order of the system of FEM equations is demonstrated in comparison with the modeling of CFST-structures in a volumetric formu-lation in existing design complexes using SOLID elements for a concrete core with 3 degrees of freedom in each of the nodes, and SHELL elements for a steel tube with 6 degrees of freedom in each of the nodes, with a comparable accuracy in determining the stress-strain state. The behavior of steel and concrete in the presented work is assumed to be linearly elastic, however, the described calculation method can be generalized to the case of using nonlinear deformation models of materials.","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129738024","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 : 2021-06-21DOI: 10.34031/2618-7183-2021-4-2-19-28
S. Tarek, V. Tolstikov
The article discusses the main aspects of the construction of dams with a symmetrical profile from the mate-rial "solid embankment" or other names ("lean" concrete, cemented "sand and gravel mixture" CSG). The design of typical profiles of dams of implemented projects is considered, and information regarding the characteristics and methods of production of this material is provided. The main properties of this material and the principle of its preparation are considered. The work in this area of engineers from Russia, Japan, Iran, Korea, China, and Turkey is analyzed. These dam structures are characterized by high reliability and efficiency, but also, most importantly, by a much higher adaptability or high speed of construction, which is little dependent on local natural factors than traditional rolled concrete dams.
{"title":"WORLD EXPERIENCE IN THE CONSTRUCTION OF GRAVITY DAMS FROM A PARTICULARLY LEAN CONCRETE MIX","authors":"S. Tarek, V. Tolstikov","doi":"10.34031/2618-7183-2021-4-2-19-28","DOIUrl":"https://doi.org/10.34031/2618-7183-2021-4-2-19-28","url":null,"abstract":"The article discusses the main aspects of the construction of dams with a symmetrical profile from the mate-rial \"solid embankment\" or other names (\"lean\" concrete, cemented \"sand and gravel mixture\" CSG). The design of typical profiles of dams of implemented projects is considered, and information regarding the characteristics and methods of production of this material is provided. The main properties of this material and the principle of its preparation are considered. The work in this area of engineers from Russia, Japan, Iran, Korea, China, and Turkey is analyzed. These dam structures are characterized by high reliability and efficiency, but also, most importantly, by a much higher adaptability or high speed of construction, which is little dependent on local natural factors than traditional rolled concrete dams.","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132296079","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 : 2021-06-21DOI: 10.34031/2618-7183-2021-4-2-5-11
A.A. Al' Shemali A.A.
Problem of developing methods for protecting buildings and structures from the vibrations transmitted to them from the soil under the action of seismic effects is extremely important to date. One of these modern methods is seismic pads. The purpose of this work was to study the effectiveness of adding a pad of granu-lar metamaterials under the foundation of the building to decrease influence of seismic shear waves. The Finite Element Analysis of Mohr-Coulomb models was used to achieve this goal. The FE model consists of a ten-story superstructure rested on the slab foundation, under which there is a layer of granular metamateri-als. The values of five variables that affect the mechanical properties of these metamaterials were analyzed (density – cohesion – internal friction angle – Young's modulus – Poisson's ratio) for two different pad thicknesses. The dynamic analysis performed using the software package Abaqus/CAE showed the effec-tiveness of the granular metamaterials in their ability to significantly reduce magnitudes of displacements, velocities and accelerations in the building compared to the same values in the absence of these metamateri-als. The analysis also revealed that among the studied variables, the cohesion is the parameter most influenc-ing the effectiveness of metamaterials in their ability to dissipate seismic waves, while no significant effect was observed for the other parameters
{"title":"DRUCKER-PRAGER MODELS FOR DYNAMIC ANALYSIS OF GRANULAR METAMATERIALS IN EARTHQUAKE ENGINEERING","authors":"A.A. Al' Shemali A.A.","doi":"10.34031/2618-7183-2021-4-2-5-11","DOIUrl":"https://doi.org/10.34031/2618-7183-2021-4-2-5-11","url":null,"abstract":"Problem of developing methods for protecting buildings and structures from the vibrations transmitted to them from the soil under the action of seismic effects is extremely important to date. One of these modern methods is seismic pads. The purpose of this work was to study the effectiveness of adding a pad of granu-lar metamaterials under the foundation of the building to decrease influence of seismic shear waves. The Finite Element Analysis of Mohr-Coulomb models was used to achieve this goal. The FE model consists of a ten-story superstructure rested on the slab foundation, under which there is a layer of granular metamateri-als. The values of five variables that affect the mechanical properties of these metamaterials were analyzed (density – cohesion – internal friction angle – Young's modulus – Poisson's ratio) for two different pad thicknesses. The dynamic analysis performed using the software package Abaqus/CAE showed the effec-tiveness of the granular metamaterials in their ability to significantly reduce magnitudes of displacements, velocities and accelerations in the building compared to the same values in the absence of these metamateri-als. The analysis also revealed that among the studied variables, the cohesion is the parameter most influenc-ing the effectiveness of metamaterials in their ability to dissipate seismic waves, while no significant effect was observed for the other parameters","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122021150","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 : 2021-06-21DOI: 10.34031/2618-7183-2021-4-2-12-18
D. A. Tolypin, N. Tolypina
the article proposes a rational method for processing 3D printing concrete scrap using vibration equipment, which allows obtaining a multicomponent building material with minimal electricity consumption. As a crite-rion for the degree of grinding of concrete scrap, it is proposed to use the specific surface area of the finely dispersed part of concrete scrap, which should correspond to 400-500 m2/kg. The possibility of reusing the resulting product instead of the traditional fine aggregate of quartz sand is shown. It was found that the con-crete scrap without the addition of Portland cement hardens, reaching up to 48% of the compressive strength of the control samples by 28 days. When 10% of the binder CEM I 42.5 N was added to the concrete scrap processing product, the compressive strength of fine-grained concrete increased by 106.6%, and 20% of Portland cement - by 112.2 %, compared to the strength of control samples of a similar composition on tra-ditional quartz sand after 28 days of hardening. It is noted that this is primarily due to the weak contact zone of quartz sand and the cement matrix of concrete. The use of the product of processing concrete scrap al-lows obtaining building composites based on it with the complete exclusion of natural raw materials
本文提出了一种合理的利用振动设备处理3D打印混凝土废料的方法，可以以最小的电力消耗获得多组分建筑材料。作为混凝土废料磨碎程度的判据，建议采用混凝土废料细碎部分的比表面积，应对应400-500 m2/kg。指出了该产品替代传统石英砂细骨料再利用的可能性。结果表明，未添加硅酸盐水泥的废混凝土在28天后硬化，抗压强度达到对照试样的48%。当混凝土废料加工产品中添加10%的粘结剂CEM I 42.5 N时，细粒混凝土的抗压强度比传统石英砂中相似成分的对照样品在硬化28天后的强度提高了106.6%，20%的波特兰水泥的抗压强度提高了112.2%。值得注意的是，这主要是由于石英砂和混凝土水泥基体的弱接触区。利用该产品对混凝土废料进行处理，获得以其为基础的建筑复合材料，完全排除天然原料
{"title":"AN EFFECTIVE WAY TO RECYCLE 3D PRINTING CONCRETE SCRAP","authors":"D. A. Tolypin, N. Tolypina","doi":"10.34031/2618-7183-2021-4-2-12-18","DOIUrl":"https://doi.org/10.34031/2618-7183-2021-4-2-12-18","url":null,"abstract":"the article proposes a rational method for processing 3D printing concrete scrap using vibration equipment, which allows obtaining a multicomponent building material with minimal electricity consumption. As a crite-rion for the degree of grinding of concrete scrap, it is proposed to use the specific surface area of the finely dispersed part of concrete scrap, which should correspond to 400-500 m2/kg. The possibility of reusing the resulting product instead of the traditional fine aggregate of quartz sand is shown. It was found that the con-crete scrap without the addition of Portland cement hardens, reaching up to 48% of the compressive strength of the control samples by 28 days. When 10% of the binder CEM I 42.5 N was added to the concrete scrap processing product, the compressive strength of fine-grained concrete increased by 106.6%, and 20% of Portland cement - by 112.2 %, compared to the strength of control samples of a similar composition on tra-ditional quartz sand after 28 days of hardening. It is noted that this is primarily due to the weak contact zone of quartz sand and the cement matrix of concrete. The use of the product of processing concrete scrap al-lows obtaining building composites based on it with the complete exclusion of natural raw materials","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121303361","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 : 2021-06-21DOI: 10.34031/2618-7183-2021-4-2-29-37
A. Balamirzoev, M. Murtuzov, D. Selimhanov, Z. Dibirova, A. Abdullaev
Nonlinear transverse vibrations of composite rods pre-loaded with lagging arranged symmetrically on both sides of the axis of the composite rod under the action of a statically applied transverse load are investigat-ed. The cases of attaching the lagging only to the ends of the composite rod, as well as when the laggings are continuously attached to the composite rod along its entire length, are considered. The results of the study of nonlinear transverse vibrations of composite rods under the action of a statically applied transverse load are presented. When conducting studies of transverse vibrations of composite rods, solutions of differential equations of vibration of prestressed through beams and stiffening cores of high-rise buildings are obtained. The obtained differential equations of vibration of composite rods allow us to determine the dynamic char-acteristics of prestressed through beams under various linear and boundary conditions. A method for com-posing differential equations of free and forced oscillations of prestressed through beams and stiffening cores of high-rise buildings and solving differential equations under various linear and nonlinear boundary conditions is developed. Expressions are given for determining the longitudinal forces and torques at the ends of the rod at any lo-cation of the lagging from the axis and at any different stiffness of the lagging
{"title":"NONLINEAR TRANSVERSE VIBRATIONS OF COMPOSITE RODS UNDER THE ACTION OF A STATICALLY APPLIED TRANSVERSE LOAD","authors":"A. Balamirzoev, M. Murtuzov, D. Selimhanov, Z. Dibirova, A. Abdullaev","doi":"10.34031/2618-7183-2021-4-2-29-37","DOIUrl":"https://doi.org/10.34031/2618-7183-2021-4-2-29-37","url":null,"abstract":"Nonlinear transverse vibrations of composite rods pre-loaded with lagging arranged symmetrically on both sides of the axis of the composite rod under the action of a statically applied transverse load are investigat-ed. The cases of attaching the lagging only to the ends of the composite rod, as well as when the laggings are continuously attached to the composite rod along its entire length, are considered. The results of the study of nonlinear transverse vibrations of composite rods under the action of a statically applied transverse load are presented. When conducting studies of transverse vibrations of composite rods, solutions of differential equations of vibration of prestressed through beams and stiffening cores of high-rise buildings are obtained. The obtained differential equations of vibration of composite rods allow us to determine the dynamic char-acteristics of prestressed through beams under various linear and boundary conditions. A method for com-posing differential equations of free and forced oscillations of prestressed through beams and stiffening cores of high-rise buildings and solving differential equations under various linear and nonlinear boundary conditions is developed. \u0000Expressions are given for determining the longitudinal forces and torques at the ends of the rod at any lo-cation of the lagging from the axis and at any different stiffness of the lagging","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127215156","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 : 2020-12-24DOI: 10.34031/2618-7183-2020-3-5-24-33
Mihail Sopin, S. Klyuev, M. Ageeva, R. Lesovik, G. Bogusevich
The article considers the possibility of using composite binders and magnetite as components of concrete with radiation-proof properties. The use of the developed concrete is possible not only when it is necessary to build nuclear power plants, but also to create bunkers or anti-radiation shelters. A special feature of concretes used for the protection and design of nuclear reactor cranes is their properties, which they must have. These properties include: low thermal conductivity, increased density, high temperature resistance, reduced values of the coefficient of thermal expansion, shrinkage and creep. Technogenic raw materials for the production of very heavy concrete are studied, the main physical and mechanical characteristics, the requirements that need to be considered in the selection of raw mix composition for protective concrete are analyzed. The paper presents a comparison of physical and mechanical characteristics, the advantages and disadvantages of introducing a binder of various types: cement, cement with a superlasticizer and a binder of low water consumption. It was found that the use of a low-water-consumption binder increases the physical and mechanical characteristics while reducing the consumption of cement in the raw material mix compared to traditional heavy concrete with cement.
{"title":"DEVELOPMENT OF RADIATION-PROOF CONCRETE COMPOSITIONS","authors":"Mihail Sopin, S. Klyuev, M. Ageeva, R. Lesovik, G. Bogusevich","doi":"10.34031/2618-7183-2020-3-5-24-33","DOIUrl":"https://doi.org/10.34031/2618-7183-2020-3-5-24-33","url":null,"abstract":"The article considers the possibility of using composite binders and magnetite as components of concrete with radiation-proof properties. The use of the developed concrete is possible not only when it is necessary to build nuclear power plants, but also to create bunkers or anti-radiation shelters. A special feature of concretes used for the protection and design of nuclear reactor cranes is their properties, which they must have. These properties include: low thermal conductivity, increased density, high temperature resistance, reduced values of the coefficient of thermal expansion, shrinkage and creep. Technogenic raw materials for the production of very heavy concrete are studied, the main physical and mechanical characteristics, the requirements that need to be considered in the selection of raw mix composition for protective concrete are analyzed. The paper presents a comparison of physical and mechanical characteristics, the advantages and disadvantages of introducing a binder of various types: cement, cement with a superlasticizer and a binder of low water consumption. It was found that the use of a low-water-consumption binder increases the physical and mechanical characteristics while reducing the consumption of cement in the raw material mix compared to traditional heavy concrete with cement.","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131667297","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 : 2020-12-24DOI: 10.34031/2618-7183-2020-3-5-5-14
R. Fedyuk, A. Baranov, Yu. Ilinsky, A. Azevedo
The widespread use of cellular concrete for enclosing structures forces researchers to develop ways to im-prove their performance and durability. Compositions of aerated and foam concrete with the use of waste heat power engineering have been developed. The optimal formulation ratios have been identified that con-tribute to the creation of a rigid interpore matrix and water-repellent pore protection. The regularities of the synthesis of aerated concrete and foam concrete were established, which consist in optimizing the processes of structure formation through the use of a polymineral cement-ash binder and a pore-forming agent. The mix composition intensifies the process of hydration of the system, which leads to the synthesis of a poly-mineral highly porous heterodispersed matrix. The increased activity and granulometry of aluminosilicates predetermine an increase in the number of contacts and mechanical adhesion between particles during com-paction, strengthening the framework of the interpore partitions. The mechanism of the influence of the composition of the concrete mix on the microstructure of the composite is established. The calculated sound insulation of airborne noise shows sufficient characteristics for using aerated concrete blocks as enclosing structures. One of the main advantages of aerated concrete is its low thermal conductivity, which is especial-ly important from the point of view of ensuring the energy efficiency of buildings and structures. Even in spite of the high values of open porosity of the developed aerated concrete, the rigid frame makes it possible to achieve almost 2 times higher frost resistance characteristics than that of the reference specimen
{"title":"PERFORMANCES OF HIGH POROUS CELLULAR CONCRETE","authors":"R. Fedyuk, A. Baranov, Yu. Ilinsky, A. Azevedo","doi":"10.34031/2618-7183-2020-3-5-5-14","DOIUrl":"https://doi.org/10.34031/2618-7183-2020-3-5-5-14","url":null,"abstract":"The widespread use of cellular concrete for enclosing structures forces researchers to develop ways to im-prove their performance and durability. Compositions of aerated and foam concrete with the use of waste heat power engineering have been developed. The optimal formulation ratios have been identified that con-tribute to the creation of a rigid interpore matrix and water-repellent pore protection. The regularities of the synthesis of aerated concrete and foam concrete were established, which consist in optimizing the processes of structure formation through the use of a polymineral cement-ash binder and a pore-forming agent. The mix composition intensifies the process of hydration of the system, which leads to the synthesis of a poly-mineral highly porous heterodispersed matrix. The increased activity and granulometry of aluminosilicates predetermine an increase in the number of contacts and mechanical adhesion between particles during com-paction, strengthening the framework of the interpore partitions. The mechanism of the influence of the composition of the concrete mix on the microstructure of the composite is established. The calculated sound insulation of airborne noise shows sufficient characteristics for using aerated concrete blocks as enclosing structures. One of the main advantages of aerated concrete is its low thermal conductivity, which is especial-ly important from the point of view of ensuring the energy efficiency of buildings and structures. Even in spite of the high values of open porosity of the developed aerated concrete, the rigid frame makes it possible to achieve almost 2 times higher frost resistance characteristics than that of the reference specimen","PeriodicalId":127090,"journal":{"name":"Construction Materials and Products","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117133321","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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