scholarly journals Experimental and calculated evaluation of carbon fiber reinforcing for increasing concrete columns carrying capacity

2019 ◽  
Vol 97 ◽  
pp. 04007 ◽  
Author(s):  
Ekaterina Kuzina ◽  
Vladimir Rimshin
Keyword(s):  
Composite Material ◽  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Bearing Capacity ◽  
Carbon Fibers ◽  
Carrying Capacity ◽  
Concrete Columns ◽  
The Other ◽  
Concrete Elements ◽  
Discrete Arrangement

The article presents the concrete columns tests results reinforced with canvases based on carbon fibers FibARM Tape 530/300 and FibARM Lamel 14/100 slats, the calculation of the use effectiveness for strengthening the compressed reinforced concrete elements. Three groups of columns were tested: unreinforced columns, columns reinforced with FibARM Tape 530/300 canvases in one layer, reinforced with FibARM Lamel 14/100 lamella (width is 100 mm), while one of the samples was reinforced with lamella only, and the other was reinforced both lamella and clamps. In addition, it was proposed calibration calculation of concrete columns reinforced with canvases based on carbon fibers FibARM Tape 530/300, the calculation purpose was to determine the bearing capacity for evaluating the suitability in the further structure operation after columns strengthening. According to the experiment results, data were obtained on the carrying capacity of centrally compressed concrete columns reinforced with carbon fiber both with a discrete arrangement of bands (strips) made of composite material along the height of the structures, as well as with their continuous wrapping (analogue of reinforced concrete holder). According to the experiment results, data were obtained on the carrying capacity of centrally compressed concrete columns reinforced with carbon fiber, both with a discrete arrangement of bands (strips) made of composite material along the height of structures, and with their continuous wrapping (analogue of reinforced concrete holder).

SETTING A DIAGRAM APPROACH TO CALCULATING VIBRATED, CENTRIFUGED AND VIBROCENTRIFUGED REINFORCED CONCRETE COLUMNS WITH A VARIATROPIC STRUCTURE

2020 ◽  
pp. 22-34
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
М. П. Нажуев
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
The Cross ◽  
Concrete Elements ◽  
Diagram Approach

Состояние проблемы. Железобетонные элементы изготавливаются, как правило, по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что реализуется лишь в вибрированных колоннах. Результаты. В рамках диаграммного подхода предложены итерационный, приближенный и упрощенный способы расчета несущей способности железобетонных вибрированных, центрифугированных и виброцентрифугированных колонн. Выводы. Расчет по диаграммному подходу показал существенно более подходящую сходимость с опытными данными, чем расчет по методике норм, а также дал лучшие результаты при использовании дифференциальных характеристик бетона, чем при использовании интегральных и, тем более, нормативных характеристик бетона. Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed. Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.

scholarly journals Optimizing of system "column-cfrp lamellas" with the strengthening of civil structures

2021 ◽  
Vol 9 (1) ◽  
pp. 1-5
Author(s):  
Irina Mayackaya ◽  
Batyr Yazyev ◽  
Anastasia Fedchenko ◽  
Denis Demchenko
Keyword(s):  
Reinforced Concrete ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Concrete Structures ◽  
Polymeric Composite ◽  
Concrete Columns ◽  
Reinforced Concrete Structures ◽  
Structural Elements ◽  
Civil Structures ◽  
Concrete Elements

Reinforced concrete elements of structures in the form of columns, beams, ceilings are widely used in the construction of buildings and structures of industrial and civil construction. In most cases, the columns serve as supports for other building elements, for example, crossbars, slabs, girders, beams. One of the cycles of the work of reinforced concrete structures is the state of their repair and reconstruction, including the stages of strengthening the elements. There is a problem of strengthening of reinforced concrete columns. The article deals with the issue of reinforcing columns and other structural elements having a cylindrical surface, with polymeric composite materials in the form of carbon fiber lamellae. The use of composite materials allows to increase the service life and strength of reinforced concrete structures used in construction.

Improvement of Regulatory Calculation of the Load-Carrying Capacity of Vibrated, Centrifuged, and Vibrocentrifuged-Based Iron-Concrete Columns with Variatropic Structure

2020 ◽  
pp. 78-84
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
А. А. Чернильник
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Carrying Capacity ◽  
Concrete Columns ◽  
Strength Analysis ◽  
Load Carrying Capacity ◽  
Load Bearing Capacity ◽  
Load Carrying ◽  
Regulatory Approach ◽  
Concrete Elements

Состояние проблемы. Сжатые железобетонные элементы изготавливаются по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что соответствует действительности лишь в вибрированных колоннах. Результаты. Разработан усовершенствованный нормативный подход к расчету прочности центрифугированных и виброцентрифугированных железобетонных колонн, заключающийся в использовании в расчете интегральных или дифференциальных характеристик бетона. Выводы. Расчет прочности коротких центрально сжатых вибрированных, центрифугированных и виброцентрифугированных колонн по усовершенствованному нормативному подходу дал наилучшие результаты с использованием дифференциальных характеристик бетона, различающихся по сечению. Statement of the problem. Compressed reinforced concrete elements are manufactured according to three main technologies - vibrating, centrifuging and vibrocentrifugation. However, all the main calculated dependences for determining their load-bearing capacity were derived based on the main postulate - the constancy and equality of the characteristics of concrete over the cross section, which corresponds to reality only in vibrated columns. Results. An improved regulatory approach has been developed for calculating the strength of centrifuged and vibrocentrifuged reinforced concrete columns, which involves using the calculation of integral or differential characteristics of concrete. Conclusions. Strength analysis of short centrally compressed vibrated, centrifuged and vibrocentrifuged columns using an improved regulatory approach yielded the best results using differential characteristics of concrete varying in cross section.

The Ways to Reduce the Materials Consumption of Compressed Reinforced Concrete Elements

2018 ◽  
Vol 931 ◽  
pp. 321-327
Author(s):  
Viktor A. Muradyan
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Columns ◽  
Fracture Pattern ◽  
Reinforcing Steel ◽  
Optimal Parameters ◽  
Reinforced Concrete Columns ◽  
Concrete Elements

The article deals with the main advantages of reinforced concrete columns with recessed fittings. The method of testing the prototype columns is described. In addition, the influence of various factors on the fracture pattern and bearing capacity of such columns is explained. The standard reinforced concrete columns are given below and the optimal parameters for saving reinforcing steel are observed [1-7].

scholarly journals CAPACITY FLEXIBLE COMPRESSED REINFORCED CONCRETE ELEMENTS REINFORCED WITH STEEL SHEETS

2018 ◽  
Vol 1 (50) ◽  
pp. 79-87
Author(s):  
L. I. Storozhenko ◽  
S. O. Murza ◽  
О. І. Yefimenko
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Carrying Capacity ◽  
Applied Load ◽  
Experimental Studies ◽  
Load Bearing Capacity ◽  
Steel Reinforced Concrete ◽  
Steel Sheets ◽  
Dependence Graphs ◽  
Concrete Elements

The experimental studies results of reinforced concrete elements with sheet reinforcement load bearing capacity are presented. The drawing of experimental designs is shown. The bearing capacity dependence graphs of the tested steel-reinforced concrete samples with sheet reinforcement on the height of the element and dependence graphs of tested steel-reinforced concrete samples with sheet reinforcement carrying capacity on the applied eccentricity are constructed. The photo shows the destruction character of experimental steel-concrete samples with sheet reinforcement depending on their height. The general schedule of bearing capacity dependence on the height of the element and the eccentricity of the applied load is constructed.

scholarly journals Influence analysis of the main types of defects and damages on bearing capacity in reinforced concrete elements and their research methods

2019 ◽  
Vol 22 (22) ◽  
pp. 24-29
Author(s):  
Maksym Lobodanov ◽  
Pavlo Vegera ◽  
Zinoviy Blikharskyy
Keyword(s):  
Composite Material ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Strain State ◽  
Complete Separation ◽  
Building Structures ◽  
Joint Work ◽  
Economic Trends ◽  
Single Method ◽  
Concrete Elements

Abstract In current economic trends, changes in construction using are required. It usually leads to changes in value and type of the working load on building structures, with the requirement to rate the technical state and replace or strengthen the elements. An important aspect of determining the residual bearing capacity of damaged bending reinforced concrete elements is the research concerning the influence of difference defects and damages on the change of strength and deformability. In the article main types of damages and defects, methods of studies of damaged reinforced concrete elements and the expediency of usage of this elements are described. However, most methods are suitable only for certain defects and damages due to the large complexity of calculations and the consideration of multifactoriality. Significant complexity of a single method for calculating damaged elements depends on the possible changing stress strain state of an element in combination with certain defects and damages, the presence of a non-complete separation where during loading or alteration of the damaged element the fractions become included in the work, reinforced concrete is the composite material which carrying complexity in calculating the joint work of its components.

Axial Compressive Experimental Study on Full-Scale Square Concrete Columns Confined by High-Strength Spiral Hoops

2012 ◽  
Vol 476-478 ◽  
pp. 2036-2041
Author(s):  
Zhen Bao Li ◽  
Wen Jing Wang ◽  
Wei Jing Zhang ◽  
Yun Da Shao ◽  
Bing Zhang ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Yield Strength ◽  
Bearing Capacity ◽  
High Strength Steels ◽  
High Strength ◽  
Concrete Columns ◽  
Full Scale ◽  
The Other ◽  
Reinforced Concrete Columns ◽  
Deformation Ability

3 specimens of full-scale reinforced concrete columns were tested under monotonic axial loading, in which the hoop configuration of one specimen was #, and the other two used the two-directional composite spiral hoops. The axial compressive performances of full-scale reinforced concrete columns confined by different configurations and strengths of hoops were discussed. One of the columns confined by spiral hoops used high-strength steels with the yield strength of 1000MPa as hoops, while the other two columns used ordinary-strength steel with yield strength of 400MPa. Columns confined by spiral hoops exhibited slight higher bearing capacity and better deformation ability than columns with hoop configuration #. The results also indicated that compared with the specimen used ordinary-strength hoops, the bearing capacity of the specimen used high-strength hoops was basically the same, but the deformation ability improved obviously.

Reduce the Impact of Dynamic Strength of Concrete under Fire Conditions on Bearing Capacity of Reinforced Concrete Columns

2013 ◽  
Vol 475-476 ◽  
pp. 1563-1566 ◽  
Author(s):  
Ashot Tamrazyan
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Dynamic Strength ◽  
Dynamic Effect ◽  
Concrete Columns ◽  
Fire Effects ◽  
Dynamic Loads ◽  
Dynamic Coefficient ◽  
The Impact ◽  
Concrete Elements

This article provides an example of the calculation of eccentrically compressed reinforced concrete elements operating under dynamic loads and fire effects. Dynamic coefficient depending on temperature and strain rate, the results of experiment varies widely from 0.4 to 0.8. It is possible to reveal the influence of the dynamic effect on the reduction of the bearing capacity of the pylon and fire and columns of 40%.

scholarly journals SETTING A DIAGRAM APPROACH TO CALCULATING VIBRATED, CENTRIFUGED AND VIBROCENTRIFUGED REINFORCED CONCRETE COLUMNS WITH A VARIATROPIC STRUCTURE

2021 ◽  
pp. 30-44
Author(s):  
L. R. Mailyan ◽  
S. A. Stel'makh ◽  
E. M. Shcherban ◽  
M. P. Nazhuev
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
The Cross ◽  
Concrete Elements ◽  
Diagram Approach

Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed.Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.

EXPERIMENTAL INVESTIGATION ON STRENGTHENING OF REINFORCED CONCRETE COLUMNS WITH CARBON CONCRETE COMPOSITE

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Klaus Holschemacher ◽  
Dennis Messerer ◽  
Wladislaw Polienko
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Bearing Capacity ◽  
Cross Sections ◽  
Concrete Columns ◽  
Experimental Program ◽  
Load Bearing Capacity ◽  
Reinforced Concrete Columns ◽  
Load Bearing ◽  
Concrete Members

The application of textile reinforced concrete is well-approved technique for strengthening of reinforced concrete members. When using carbon fiber meshes and carbon fiber reinforced polymer bars as reinforcement, this material is called carbon concrete composite. Based on the outstanding properties of carbon fibers, carbon concrete composite is characterized by high bending and tensile strength, and good durability. Therefore, carbon concrete composite is increasingly applied as replacement for ordinary steel bar or steel mesh reinforced concrete. It is favorable building material for production of new buildings and for strengthening of existing reinforced concrete members. In the context of strengthening of existing reinforced concrete columns, it is a usual procedure to cover the member’s surface with a thin layer of carbon concrete composite aiming on reduction of lateral strains of the core concrete when load is increasing. The result is an increased load-bearing capacity of the strengthened column. However, there is insufficient knowledge about the influence of curvature of the carbon meshes in circular cross-sections and in the corners of rectangular cross-sections on their load-bearing capacity. For this reason, an experimental program started to study the influence of curvature, number and type of mesh layers and specimen dimensions on structural behavior of strengthened columns under axial loading. As main outcome it can be stated that besides the curvature other parameters like yarn properties are of essential importance.

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