scholarly journals Ductility of Concrete Beams Reinforced with FRP Rebars

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 424
Author(s):  
Tvrtko Renić ◽  
Tomislav Kišiček
Keyword(s):  
Experimental Data ◽  
Theoretical Analysis ◽  
Cross Sections ◽  
Concrete Beams ◽  
Current Knowledge ◽  
Bending Moment ◽  
Bending Capacity ◽  
Frp Reinforcement ◽  
Concrete Elements ◽  
Standard Steel

Concrete beams reinforced with FRP rebars have greater durability than standard steel reinforced elements. The main disadvantage of using FRP rebars is the low ductility of elements which may be unacceptable in certain situations. There are several different ways of increasing the ductility of concrete elements, which are analyzed in this paper. They are compared based on efficiency, influence on durability and ease of construction. Less analyzed and tested methods are given more attention to try and expand the current knowledge and possibilities. For methods that lack experimental data, theoretical analysis is undertaken to assess the possible influence of that method on the increase in ductility. Ductility was obtained by calculating bending moment–curvature diagrams of cross sections for different reinforcement layouts. One method that lacks experimental data is confining the compressive area of beams with tensile FRP reinforcement. Theoretical analysis showed that confining the compressive area of concrete can significantly increase the ductility and bending capacity of beams. Since experimental data of beams reinforced with FRP rebars in tension and confined compressive area is sparse, some suggestions on the possible test setups are given to validate this theoretical analysis. Concrete beams reinforced with FRP can be detailed in such a way that they have sufficient ductility, but additional experimental research is needed.

A Dynamic Test of Fully Prestressed Concrete Beams

2011 ◽  
Vol 368-373 ◽  
pp. 2483-2490
Author(s):  
Yao Ting Zhang ◽  
Yi Zheng ◽  
Hong Jian Li
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Theoretical Analysis ◽  
Natural Frequency ◽  
Axial Force ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Dynamic Test ◽  
Modified Formula

A dynamic test of two unbonded fully prestressed concrete beams has been conducted. The results indicate that the natural frequency of beams increases with the prestress force, which is opposite to the analytical arguments for homogeneous and isotropic beams subject to axial force. This paper explains the change in frequencies by discussing the change in the elastic modulus. A modified formula is also proposed, and the experimental data agree well with the theoretical analysis.

Experimental Study on Flexural Performances of Concrete Beams Strengthened with Near-Surface Mounted (NSM) FRP Reinforcement

2010 ◽  
Vol 163-167 ◽  
pp. 3634-3639
Author(s):  
Li Li Sui ◽  
Tie Jun Liu ◽  
Feng Xing ◽  
Yu Xiang Fu
Keyword(s):  
Experimental Study ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Flexural Stiffness ◽  
Test Results ◽  
Near Surface ◽  
Bending Performance ◽  
Bending Capacity ◽  
Frp Reinforcement ◽  
Near Surface Mounted

This paper illustrates the results of an experimental study on the bending performance of concrete beams strengthened with near-surface mounted (NSM) FRP reinforcement. The critical parameter of the embedded length of NSM-FRP plates was investigated in particularly. The test results indicated that NSM-FRP reinforcement can significantly improve the strength and crack resistance capacity of the concrete beam, reducing the size of cracks. The embedded length of the NSM-FRP plate has distinct influence on the cracking and bending capacity, the flexural stiffness, and the crack developments of the concrete beam. As the embedded length increased, the bending capacity and the flexural stiffness increased correspondingly and the crack developed more intensively.

scholarly journals Analytical Model to Predict Residual Flexural Capacity of Recycled Aggregate Concrete Beams with Corroded Longitudinal Rebars

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Zhenghao Zou ◽  
Guojiao Yang ◽  
Tian Su
Keyword(s):  
Experimental Data ◽  
Theoretical Analysis ◽  
Strain Distribution ◽  
Concrete Beams ◽  
Plane Section ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Flexural Behavior ◽  
Flexural Capacity ◽  
Aggregate Concrete

This paper presents the results of research on the flexural behavior of recycled aggregate concrete (RAC) beams. The correlation between flexural behavior and the corrosion level of longitudinal rebar was analysed. Based on theoretical analysis and experiment results, the influence of corrosion on flexural cracking moment was analysed and a model to predict the residual flexural capacity of RAC beams with corroded longitudinal rebars was established. The experimental results show that the development degree of cover cracks deepens with the increase of the corrosion level, and the experimental data also demonstrate that the strain distribution of concrete in the midspan of beams conforms to the plane section assumption better when the corrosion level is little but no longer satisfies the plane section assumption when the corrosion level is high.

scholarly journals Simulation of the Stress-Strain State of Eccentrically Compressed and Tensioned Reinforced Concrete Beams

2020 ◽  
Vol 2 (1) ◽  
pp. 207-214
Author(s):  
Vasyl Karpiuk ◽  
Yuliia Somina ◽  
Oksana Maistrenko ◽  
Fedir Karpiuk
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Strain State ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Improved Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Strain Behaviour ◽  
Concrete Elements

AbstractThe paper deals with the working peculiarities of the support zones of reinforced concrete elements subject to bending with due account of the eccentric compression and tension. The authors performed simulation of the stress-strain behaviour of the indicated structures with the aid of “Lira” software which results are shown in the graphical and tabulated form. The performed simulation allowed of tracing the work of the studied sample beams till collapse. Such approach made it possible to single out and generalize the main collapse patterns of the inclined cross-sections of the reinforced concrete elements subject to bending on which basis the authors developed the improved method to calculate their strength (Karpiuk et al., 2019).

scholarly journals Ultimate flexural strength of prestressed concrete beams: validation and model error evaluation

2018 ◽  
Vol 11 (2) ◽  
pp. 307-330
Author(s):  
M. W. MOURA ◽  
M. V. REAL ◽  
D. D. LORIGGIO
Keyword(s):  
Cross Section ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Bending Moment ◽  
Experimental Tests ◽  
Error Evaluation ◽  
Moment Capacity ◽  
Percentage Difference ◽  
The Cross ◽  
Concrete Elements

Abstract In this work a computational model is presented to evaluate the ultimate bending moment capacity of the cross section of reinforced and prestressed concrete beams. The computational routines follow the requirements of NBR 6118: 2014. This model is validated by comparing the results obtained with forty-one experimental tests found in the international bibliography. It is shown that the model is very simple, fast and reaches results very close to the experimental ones, with percentage difference of the order of 5%. This tool proved to be a great ally in the structural analysis of reinforced and prestressed concrete elements, besides it is a simplified alternative to obtain the cross section ultimate bending moment.

On the Experimental Analysis of Temperature Influence on Stiffness of Reinforced Concrete Beams

2015 ◽  
Vol 6 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Robert Kowalski ◽  
Michal Glowacki ◽  
Marian Abramowicz
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Cross Sections ◽  
Concrete Beams ◽  
Rectangular Cross Section ◽  
Thermal Strain ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Stiffness Reduction ◽  
Tensile Zone

The paper presents results of experimental research whose main topic was determination of stiffness reduction in bent reinforced concrete beams in two cases: when only tensioned or only compressed zone was exposed to high temperature. Twenty four reinforced concrete beams with rectangular cross-section were prepared for the experiment. Eight groups of beams were prepared in total: 2 with reinforcement ratio - 0.44 and 1.13% x 2 levels of load - 50 or 70% of destructive force ensuring the constant value of bending moment in the centre part of heated beams x 2 static schemes. Three beams were used in each group. Significant cross-section stiffness reduction was observed in beams where the tensile zone was heated. This was due to considerable elongation of the bars where the steel load elongation summed up with the free thermal strain. In beams where the compressed zone was heated the stiffness reduction was observed only after the time where the tensile zone heated cross-sections were already destroyed.

scholarly journals Residual resource of power resistance during building structures deformation

2019 ◽  
Vol 135 ◽  
pp. 03009 ◽  
Author(s):  
Ekaterina Kuzina ◽  
Vladimir Rimshin ◽  
Alexey Neverov
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Residual Life ◽  
Deformable Body ◽  
Bending Moment ◽  
Discrete Models ◽  
Building Structures ◽  
Resistance To Deformation ◽  
Concrete Elements ◽  
Research And Design

Modern scientific research and design developments, based on the fundamental principles of physics, mechanics and thermodynamics, are developing in a phenomenological direction. This implementation is found both in traditional integrated models of reinforced concrete using the advantages of computer technology, and in discrete models following the grid methods of solid deformable body mechanics. Discrete models in content and chronology over time are hereditary with respect to integral models. The theoretical basis for calculating the residual life of the force resistance to deformation, determines the stiffness of the cross sections of reinforced concrete elements with a maximum bending moment and with zero bending moment are presented in this article.

A comprehensive theoretical analysis of 22Ne nucleus by using different density distributions, different nuclear potentials and different cluster approach

2020 ◽  
Vol 29 (01) ◽  
pp. 1950112
Author(s):  
M. Aygun
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Theoretical Analysis ◽  
Cross Sections ◽  
Angular Distributions ◽  
Cluster Approach ◽  
Systematic Analysis ◽  
Density Distributions ◽  
Theoretical Approaches ◽  
Scattering Cross Sections

In this study, a systematic analysis is made on the [Formula: see text]Ne nucleus. First, using different theoretical approaches, we show eight density distributions for the [Formula: see text]Ne nucleus. For there densities, we obtain the elastic scattering angular distributions of [Formula: see text]Ne by [Formula: see text]C and [Formula: see text]C targets. Then, to offer alternative nuclear potentials in explaining nuclear interactions related to [Formula: see text]Ne projectile, we calculate the elastic scattering cross-sections of [Formula: see text]C and [Formula: see text]C reactions by using six different nuclear potentials. Finally, we investigate cluster structures of the [Formula: see text]Ne nucleus via a simple cluster approach. We compare the calculated elastic scattering angular distributions with the experimental data.

scholarly journals Vibrations of cracked reinforced and prestressed concrete beams

2008 ◽  
Vol 6 (2) ◽  
pp. 155-164 ◽  
Author(s):  
Zsolt Huszár
Keyword(s):  
Cross Sections ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Bending Rigidity ◽  
Elastic Range ◽  
Non Linear ◽  
Linear Vibrations ◽  
Prestressed Beams

The dynamic behaviour of bent reinforced concrete beams in elastic range is significantly influenced by cracks caused by former loads. Considering this fact a more accurate calculation of the eigenfrequencies of the beams is available. Experiments have shown that the features of vibration differ from the results obtained by the well-known linear model, if cracked zones exist. The cause of this phenomenon is that the bending rigidity of the cross-sections in the cracked range depends on the sign of the actual bending moment. Therefore the vibration shows non-linear characteristics in the elastic range as well. The dynamic behavior of bent prestressed concrete beams is similar. The dynamic characteristics of prestressed beams besides cracks is influenced also by the intensity and eccentricity of the axial force. For a detailed investigation of the problem, experiments and non-linear analysis were performed. On the basis of these the virtual eigenfrequencies of the non-linear vibrations were determined.

scholarly journals Pengaruh Penambahan Tulangan Tekan Terhadap Momen Kapasitas Lentur dan Daktilitas Balok

2020 ◽  
Vol 3 (2) ◽  
pp. 97-106
Author(s):  
Jaya Permana ◽  
M. Muhtaris ◽  
Eka Susanti ◽  
Yanisfa Yanisfa
Keyword(s):  
Concrete Beams ◽  
Bending Moment ◽  
Strength Testing ◽  
Flexural Capacity ◽  
Moment Capacity ◽  
Know How ◽  
Beam Design ◽  
Bending Capacity ◽  
The Moment ◽  
Reinforcement Beam

Double reinforcement beam design, increasing the compressive reinforcement can increase the flexural capacity moment and ductility of concrete beams. This helps planners to improve flexural capacity moment with minimal dimensions, that are still acceptable in terms of aesthetics. The purpose of this study is to know how much influence the increasing compressive reinforcement can increase the flexural capacity moment and ductility of concrete beams. Experimental research with beam specimens 20x20x60 cm, 2D16 tensile reinforcement, fc’ 25 mpa and fy 320 mpa. With a ratio of compressive reinforcement to tensile reinforcement of 0.14; 0.25 and 0.59. Flexural strength testing uses flexible loading with a roll-pined joint. The process of load reading is yield phase until ultimate phase. The results of the analysis show an uses of increasing compressive reinforcement can increase the moment of flexural capacity and ductility. The addition of compressive reinforcement reached 25% from tensile reinforcement, can increase the moment of bending capacity by 4.47%, but uses compressive reinforcement reached 50% of tensile reinforcement, only increasing the bending moment capacity of 1.43%. For ductility, uses compressive reinforcement reaches 25% from tensile reinforcement, can increase ductility by 19.73% and an increase of 26.17% by adding compressive reinforcement up to 50% of tensile reinforcement. From these results it appears that the more improvements added, the more the ductility increases and the less the moment the flexural capacity increases.

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