scholarly journals Steel stress patterns between two primary cracks in concrete

2020 ◽  
Vol 21 ◽  
pp. 17-23
Author(s):  
Andor Windisch
Keyword(s):  
Reinforced Concrete ◽  
Load Level ◽  
Bond Stress ◽  
Single Crack ◽  
Concrete Element ◽  
Structural Concrete ◽  
The Real ◽  
Primary Crack ◽  
Local Slip ◽  
Stress Patterns

The national and international codes and standards and the literature consider the stress patterns either in case of a single crack or of equidistant primary cracks which developed at the same load level. Moreover, most FE models consider smeared cracks which do not allow for any insight in the real inner behavior of structural concrete. This paper considers the stochastic character of the concrete tensile strength’s distribution along the reinforced concrete element and a realistic local bond stress vs. slip relationship with its hysteretic character when the sign of local slip changes due to the occurrence of a new primary crack.

scholarly journals Features of calculation and design of complex concrete monolithic slabs

2018 ◽  
Vol 251 ◽  
pp. 02027
Author(s):  
Vitaly Kuznetsov ◽  
Yulia Shaposhnikova
Keyword(s):  
Reinforced Concrete ◽  
Numerical Experiment ◽  
Concrete Structures ◽  
Structural Concrete ◽  
Design Rules ◽  
The Real ◽  
Composite Slabs

In the article features of designing of reinforced concrete floors on the profiled flooring, leaning against steel I-beams are considered. Specific features of calculating the strength of composite slabs in accordance with JV 35.13330.2011 “Bridges and pipes” and SP 266.1325800.2016 “Structural concrete structures. Design rules”. A method for determining the forces based on the real ratio of the rigidity of the overlap elements is also considered. The analysis of the results of the numerical experiment made it possible to establish the optimum coefficients of the use of materials that can be used in the design of combined overlaps.

BUCKLING OF A REINFORCED CONCRETE ELEMENT DYNAMICALLY DEFINED BY ACI209R CREEP CRITERIA

2019 ◽  
Author(s):  
Alexandre de Macêdo Wahrhaftig ◽  
Kaique Moreira Matos Magalhães
Keyword(s):  
Reinforced Concrete ◽  
Concrete Element

scholarly journals Experimental study of the strengthening effect of reinforced concrete columns jacketed under service load level

2018 ◽  
Vol 183 ◽  
pp. 02008 ◽  
Author(s):  
Pavlo Krainskyi ◽  
Yaroslav Blikharskyy ◽  
Roman Khmil ◽  
Zinoviy Blikharskyy
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Concrete Columns ◽  
Load Level ◽  
Strengthening Effect ◽  
Engineering Structures ◽  
Reinforced Concrete Columns ◽  
Technical Modification ◽  
Service Load

The need of structural retrofitting and strengthening of different buildings, engineering structures or their elements is always present. Among the main reasons are demages and material deterioration due to aging, improper maintenance or physical damages; planed repairs; reconstruction or extension of the building; technical modification or complete change of operations inside the building or the structure, etc. In some cases operation of the building during retrofitting or strengthening of its structures has to be partially or fully stopped. In other cases the strengthening process takes place while the building is still operational which means that structures are strengthened under service loads. The main goal of this research is to determine the strengthening effect of reinforced concrete jacketing applied to columns under service load level. For that the experimental study of six reinforced concrete columns were carried out: four reference columns, both strengthened by jacketing and unstrengthened and two strengthened under service load. The main results of the research are presented.

scholarly journals The seismic performance of steel encased reinforced concrete bridge piles

1983 ◽  
Vol 16 (2) ◽  
pp. 123-140
Author(s):  
R. J. T. Park ◽  
M. J. N. Priestley ◽  
W. R. Walpole
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Theoretical Investigation ◽  
Axial Load ◽  
Lateral Displacement ◽  
Load Level ◽  
Concrete Bridge ◽  
Reinforced Concrete Bridge ◽  
Outside Diameter ◽  
Good Agreement

An experimental and theoretical investigation into the seismic performance of steel encased reinforced concrete bridge piles is described. Six test units were designed, constructed and tested
under cyclic lateral displacement-controlled loading. The units had
an outside diameter of 360 mm and a steel casing thickness of 5 mm. Variables included the axial load level, inclusion or exclusion of internal reinforcing cages, and the influence of the casing continuity at he critical flexural sections. Sound seismic performance was observed in all of the models and good agreement between predicted and observed ultimate behaviour was obtained.

scholarly journals Strength criterion for a plane stress reinforced concrete element under a special action

Vestnik MGSU ◽  
2020 ◽  
pp. 1513-1522
Author(s):  
Natalia V. Fedorova ◽  
Vu Ngoc Tuyen ◽  
Igor A. Yakovenko
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Concrete Strength ◽  
Limit State ◽  
Strength Criterion ◽  
Structural Systems ◽  
Variable Loading ◽  
Concrete Element ◽  
Theory Of Plasticity ◽  
Concrete Elements

Introduction. Problem solving focused on the protection of buildings and structures from progressive collapse and minimization of resources, needed for this purpose, is becoming increasingly important. In many countries, including Russia, this type of protection is incorporated into national regulatory documents, and, therefore, any research, aimed at developing effective ways to protect structural systems from progressive collapse under special actions, is particularly relevant. In this regard, the present article aims to formulate effective strength criteria for such anisotropic materials as reinforced concrete to analyze plane stressed reinforced concrete structures exposed to sudden structural transformations caused by the removal of one of bearing elements. Materials and methods. To solve this problem, a variant of the generalized theory of plasticity of concrete and reinforced concrete, developed by G.A. Geniev, is proposed for application to the case of variable loading of a plane stressed reinforced concrete element. The acceptability of generalization of the strength criterion, pursuant to the theory of plasticity of concrete and reinforced concrete under static loading, and the applicability of this criterion to variable static-dynamic loading of reinforced concrete are used as the main hypothesis. An algorithm of an approximate method is presented as a solution to this problem; it allows to analyze the considered stress-strain state of plane stressed reinforced concrete elements. Results. The numerical analysis of the obtained solution, compared with the results of the experimental studies, was used to evaluate the designed strength criterion for reinforced concrete elements located in the area where the column is connected to the girder of a monolithic reinforced concrete frame in case of a sudden restructuring of a structural system. It is found out that the qualitative nature of the destruction pattern of the area under research, obtained in experiments, corresponds to the destruction pattern, identified by virtue of the analysis performed using the proposed criterion. Conclusions. The variant of the reinforced concrete strength criterion designated for the variable loading of a plane stressed reinforced concrete element and an algorithm for its implementation, based on the theory of plasticity of concrete and reinforced concrete developed by G.A. Geniev, is applicable to the analysis of a special limit state of reinforced concrete elements of structural systems of frames of buildings and structures.

scholarly journals The Proposition of an EI Equation of Square and L–Shaped Slender Reinforced Concrete Columns under Combined Loading

2021 ◽  
Vol 11 (3) ◽  
pp. 7100-7106
Author(s):  
L. Hamzaoui ◽  
T. Bouzid
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Concrete Strength ◽  
Linear Regression Analysis ◽  
Strain Curve ◽  
Load Level ◽  
Combined Loading ◽  
Actual Behavior ◽  
Factors Affecting ◽  
Slender Columns

The stability and strength of slender Reinforced Concrete (RC) columns depend directly on the flexural stiffness EI, which is a major parameter in strain calculations including those with bending and axial load. Due to the non-linearity of the stress-strain curve of concrete, the effective bending stiffness EI always remains variable. Numerical simulations were performed for square and L-shaped reinforced concrete sections of slender columns subjected to an eccentric axial force to estimate the variation of El resulting from the actual behavior of the column, based on the moment-curvature relationship. Seventy thousand (70000) hypothetical slender columns, each with a different combination of variables, were used to investigate the main variables that affect the EI of RC slender columns. Using linear regression analysis, a new simple and linear expression of EI was developed. Slenderness, axial load level, and concrete strength have been identified as the most important factors affecting effective stiffness. Finally, the comparison between the results of the new equation and the methods proposed by ACI-318 and Euro Code-2 was carried out in connection with the experimental results of the literature. A good agreement of the results was found.

SEISMIC PERFORMANCE OF GFRP-RC RECTANGULAR COLUMNS: NUMERICAL STUDY

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ehab El-Salakawy ◽  
Fangxin Ye ◽  
Yasser Mostafa Selmy
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Axial Load ◽  
Numerical Study ◽  
Concrete Strength ◽  
Weight Ratio ◽  
Concrete Columns ◽  
Load Level ◽  
Reinforced Concrete Columns ◽  
Rectangular Columns

Composite materials like glass fiber-reinforced polymer (GFRP) is becoming widely acceptable to be used as a reinforcing material due to its high ultimate tensile strength-to-weight ratio and excellent resistance to corrosion. However, the seismic behavior of GFRP-reinforced concrete columns has not been fully investigated yet. This paper presents the results of a numerical analysis of full-size GFRP-RC rectangular columns under cyclic loading. The simulated column depicts the lower part of a building column between the foundation and the point of contra-flexure at the mid-height of the column. GFRP reinforcement properties and concrete modeling based on fracture energy have been incorporated in the numerical model. Experimental validation has been used to examine the accuracy of the constructed finite element models (FEMs) using a commercially available software. The validated FEM was used to perform a parametric study, considering several concrete strength values and axial load levels, to study its influence on the performance of the GFRP-reinforced concrete columns under cyclic loading. It was concluded that the hysteretic dissipation capacity deteriorates under high axial load level due to severe softening of the concrete. The FE results showed a substantial improvement of the lateral load-carrying capacities by increasing concrete compressive strength.

The effect of dome properties on design of the axial symmetric cylindrical wall

2021 ◽  
Vol 7 (1) ◽  
pp. 11
Author(s):  
Aylin Ece Kayabekir
Keyword(s):  
Reinforced Concrete ◽  
Computer Program ◽  
Numerical Investigation ◽  
Computer Software ◽  
General Purpose ◽  
Design Stage ◽  
Cylindrical Wall ◽  
Support Condition ◽  
Structural Concrete ◽  
Analysis And Design

The usage of computer software in civil engineering has expanded in last decades. Many general-purpose and special-purpose commercial programs perform a very important function, especially at the design stage. In this study, a computer program is introduced for the analysis and design of the axial symmetric cylindrical wall considering the dome effects. Analysis processes are carried out according to Flexibility theory with long wall assumption and during the reinforced concrete (RC) design of the wall, ACI 318-Building code requirements for structural concrete are considered. In numerical investigation, the effects of the dome properties (thickness and height) on the analysis and design of the wall are investigated by performing a totally 72 case analyzes. These cases include different support condition at bottom of the wall, wall heights, dome thicknesses and heights. According to analysis results, it is concluded that effects of dome thickness and heights on the wall on the wall are very limited.

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