scholarly journals Technical and economic efficiency of reinforced concrete elements with different types of reinforcement

2018 ◽  
Vol 196 ◽  
pp. 02030
Author(s):  
Ekaterina Efimenko ◽  
Liya Mailyan ◽  
Viktor Muradyan
Keyword(s):  
Reinforced Concrete ◽  
Building Materials ◽  
Full Employment ◽  
Concrete Columns ◽  
Longitudinal Force ◽  
Reinforcement Steel ◽  
Different Types ◽  
Effective Use ◽  
Concrete Elements ◽  
Economic Use

The article presents data on the bearing capacity of columns with various combinations of prestressed and conventional reinforcement. The areas of the most effective use of such structures with different eccentricities and flexibilities are shown. The ecology of reinforcement steel is an important task that the designers of reinforced concrete structures face. The creation of effective constructive solutions, that allow to combine high technical characteristics with economic use of reinforcement steel, has become urgent and is necessary for today's development of the construction industry. In the works [1,2,3,4,5] it was shown that the solution of these problems was possible by creating conditions for the full employment of building materials properties - reinforcement and concrete. The working reinforcement is characterized by its application in the conventional and prestretched forms. At the same time, the works done in the recent years show that reinforcement, subjected to precompression, can be used in the compressed zone [6,7,8]. It is most effective in rigid reinforced concrete columns. Thus, precompression of all longitudinal reinforcement or its part allows to increase the strength of non-flexible columns with not high relative eccentricities of the external longitudinal force. At the same time, in order to obtain the greatest effect caused by the precompression of the reinforcement, certain conditions must be observed.

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.

scholarly journals Strength and deformability of reinforced concrete elements under oblique eccentric short-term dynamic compression, tension and bending

2020 ◽  
Vol 164 ◽  
pp. 14008
Author(s):  
Dmitriy Sarkisov ◽  
Nikolay Gorlenko ◽  
Gleb Gorynin ◽  
Yuri Sarkisov ◽  
Gafurzhan Izmailov ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
Dynamic Compression ◽  
Longitudinal Force ◽  
Research Data ◽  
Deformation Model ◽  
Relative Resistance ◽  
Short Term ◽  
Concrete Elements ◽  
Central Tension

The paper deals with research data of reinforced concrete rectangular and I-shaped cross-section elements, operating under oblique eccentric short-term dynamic compression, tension and bending. The method of reinforced concrete elements calculation using the theory of surfaces of relative resistance regarding strength and crack resistance is suggested. It is based on the deformation model with the use of real nonlinear diagrams of concrete and reinforcement. This method makes it possible to observe strength and crack resistance of reinforced concrete elements sections in the entire range of loadings from the central tension to axial compression. Experimental investigation of symmetrically reinforced concrete elements on oblique eccentric short-term dynamic compression, tension and oblique bending was carried out. Effect of longitudinal force level on strain distribution through the depth of section, bearing capacity, the failure scheme and other parameters are estimated.

Application Technology of Bamboo Reinforced Concrete in Building Structure

2012 ◽  
Vol 195-196 ◽  
pp. 297-302 ◽  
Author(s):  
Wei Feng Zhao ◽  
Jing Zhou ◽  
Guo Bin Bu
Keyword(s):  
Reinforced Concrete ◽  
Weight Ratio ◽  
High Strength ◽  
Concrete Columns ◽  
Building Structures ◽  
Structural Elements ◽  
High Tensile Strength ◽  
Application Technology ◽  
Steel Bar ◽  
Concrete Elements

Bamboo is mainly a tropical and subtropical plant which is found adequate in many countries. The strength of bamboo as concrete reinforcement is much lower than steel bar reinforcement. However, one of the merits is a cheap and replenishable agricultural resource and abundantly available. Due to excellent properties like high strength to weight ratio, high tensile strength and free-cutting and processing, bamboo as a potential reinforcement material in place of steel is widely available in concrete structural elements. The present paper introduces some of the existing studies and application technology of bamboo reinforced concrete elements in building structures, such as bamboo reinforced concrete columns, beams, slabs and walls.

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.

Estimation of Load Bearing Capacity of Eccentrically Compressed Reinforced Concrete Elements under Dynamic Loading in Fire Conditions

2014 ◽  
Vol 638-640 ◽  
pp. 62-65 ◽  
Author(s):  
Ashot Tamrazyan ◽  
Levon Avetisyan
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Loading ◽  
Analytical Calculation ◽  
Dynamic Strength ◽  
Concrete Columns ◽  
Dynamic Coefficient ◽  
Load Bearing Capacity ◽  
In Fire ◽  
Concrete Elements ◽  
Fire Conditions

Research of influence of fire impacts on the dynamic strength of eccentrically compressed concrete elements requires a deeper consideration. The purpose of this article is the study of dynamic strength of eccentrically compressed concrete elements in fire conditions under rapidly increasing dynamic loading. It is done the analytical calculation of eccentrically compressed reinforced concrete columns under different thermo powers conditions, there are shown the results of calculations and experimental data. It is shown a graph of dynamic coefficient for concrete depending on the time of dynamic loading and temperature.

scholarly journals Effect of PBO–FRCM Reinforcement on Stiffness of Eccentrically Compressed Reinforced Concrete Columns

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1221 ◽  
Author(s):  
Tomasz Trapko ◽  
Michał Musiał
Keyword(s):  
Reinforced Concrete ◽  
Load Capacity ◽  
Concrete Columns ◽  
Longitudinal Force ◽  
Longitudinal Reinforcement ◽  
Concrete Core ◽  
Reinforced Concrete Columns ◽  
Composite Columns ◽  
Matrix Reinforcement ◽  
Fabric Reinforced Cementitious Matrix

This paper examines the effect of PBO (P-phenylene benzobisoxazole)–FRCM (Fabric Reinforced Cementitious Matrix) reinforcement on the stiffness of eccentrically compressed reinforced concrete columns. Reinforcement with FRCM consists of bonding composite meshes to the concrete substrate by means of mineral mortar. Longitudinal and/or transverse reinforcements made of PBO (P-phenylene benzobisoxazole) mesh were applied to the analyzed column specimens. When assessing the stiffness of the columns, the focus was on the effect of the composite reinforcement itself, the value and eccentricity of the longitudinal force and the decrease in the modulus of elasticity of the concrete with increasing stress intensity in the latter. Dependences between the change in the elasticity modulus of the concrete and the change in the stiffness of the tested specimens were examined. The relevant standards, providing methods of calculating the stiffness of composite columns, were used in the analysis. For columns, which were strengthened only transversely with PBO mesh, reinforcement increases their load capacity, and at the same time, the stiffness of the columns increases due to the confinement of the cross-section. The stiffness depends on the destruction of the concrete core inside its composite jacket. In the case of columns with transverse and longitudinal reinforcement, the presence of longitudinal reinforcement reduces longitudinal deformations. The columns failed at higher stiffness values in the whole range of the eccentricities.

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 EXPERIMENTAL STUDIES ON THE INFLUENCE OF TRANSVERSE REINFORCEMENT FOR STRENGTH OF COMPRESSED REINFORCED CONCRETE ELEMENTS

2021 ◽  
Vol 10 (4) ◽  
pp. 21-28
Author(s):  
Sergey S. MORDOVSKIY ◽  
Kamil B. SHARAFUTDINOV
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Experimental Studies ◽  
Longitudinal Force ◽  
Concrete Sample ◽  
Transverse Reinforcement ◽  
Direct Factor ◽  
Rectangular Cell ◽  
Concrete Elements ◽  
Zigzag Type

The infl uence of transverse reinforcement, including indirect reinforcement, on the strength of compressed reinforced concrete elements is analyzed. This question arose in connection with the possibility of increasing the strength of short reinforced concrete elements loaded with a longitudinal force with small eccentricities within the section of the element. For such elements, the cage eff ect may appear, associated with the coeffi cient of transverse deformations, the magnitude of which is a direct factor in the destruction of the concrete sample, and the limitation of these directly aff ects the bearing capacity of the sample in the direction of increase. The infl uence of transverse reinforcement in the form of stirrups located with diff erent spacing, as well as indirect reinforcement in the form of meshes with a classical rectangular cell and meshes of the “zigzag” type is considered.

Eindringtiefe eines Hydrophobierungsmittels als Funktion der Qualität, des Feuchtigkeitsgehaltes und des Alters des Betons / Penetration depth of a water repellent agent as a function of quality, humidity and age of concrete

1999 ◽  
Vol 5 (3) ◽  
pp. 289-306
Author(s):  
H.A. Moetsch ◽  
St. Meier ◽  
A. Gerdes ◽  
F.H. Wittmann
Keyword(s):  
Building Materials ◽  
Concrete Surface ◽  
Water Repellent ◽  
Protective Measures ◽  
Capillary Suction ◽  
Treatment Need ◽  
Measuring Cell ◽  
National Highway ◽  
Different Types ◽  
Concrete Elements

Abstract Service life and lifetime of a concrete structure are not only depending on mechanical but also on chemical loads. Therefore precautions are often taken into account already in the planning- or construction phase. Certain protective measures such as water repellent treatment need preliminary tests on the finished concrete surface, in order to be applied in an optimal way . The present paper describes the preliminary tests performed on three tunnels of the second section of the Swiss National Highway N5 (Grenchen - Zuchwil) in the area of Solothurn. For the construction of the three tunnels different qualities of concrete and different types of form work were used. Furthermore the selected sections of the tunnels differ also from age and environmental conditions. A new two-chamber measuring cell developped at the Institute for Building Materials of ΕΤΗ-Zurich was applied to determine the capillary suction capacity of selected tunnel sections. Values measured on concrete elements in practice with this new cell are much more reliable than those measured with the traditional Karsten-cell.

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