A New Solution to the Height of the Compressive Area of Reinforced Concrete Beams during Service Stage

2013 ◽  
Vol 353-356 ◽  
pp. 3232-3235
Author(s):  
Jiu Jian Zheng ◽  
Li Zong ◽  
En Guo
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Calculation Method ◽  
Concrete Beams ◽  
Neutral Axis ◽  
Reinforced Concrete Beams ◽  
Specific Calculation ◽  
Flexural Members

The compressive height of reinforced concrete flexural members in service stage is generally obtained by equations based on the concept, moment-of-area of conversion area with respect to the neutral axis in tension zones equaling to that in compression zones. In this paper a specific calculation method of compressive height for singly or doubly reinforced rectangular and T-shaped cross sections is proposed.

The Study about Flexural Performance of GFRP Bar Reinforced Concrete Beams Based on Numerical Calculation Method

2010 ◽  
Vol 29-32 ◽  
pp. 1350-1356
Author(s):  
Qing Guo Yang ◽  
Yu Wei Zhang ◽  
Zhi Zhong Tu
Keyword(s):  
Reinforced Concrete ◽  
Numerical Calculation ◽  
Bearing Capacity ◽  
Calculation Method ◽  
Concrete Beams ◽  
Simple Calculation ◽  
Reinforced Concrete Beams ◽  
Displacement Curve ◽  
Gfrp Bar ◽  
Numerical Calculation Method

Replacing the steel bar with GFRP (Glass Fiber Reinforced Plastics) bar can improve the durability of concrete structure in the corrosive environment. Different ratios of GFRP bar lead huge difference performance of GFRP reinforced concrete beams; therefore, to reduce the workload, it is very necessary to study GFRP reinforced concrete beams’ performance with suitable numerical calculation method. In the study, first, GFRP reinforced concrete beams’ mechanical behavior and failure characteristics were researched through the flexural experiments of GFRP reinforced concrete beams with different ratio of GFRP bar; Second, the numerical calculation model of GFRP reinforced concrete beams was built according to experimental results which contain the load-displacement curve and the phenomenon that concrete in compression zone are crushed, then the calculation criterion of obtaining the beam’s bearing capacity was proposed. Lastly, the bending bearing capacity of GFRP bar reinforced concrete beams with different ratio of GFRP is obtained through the finite element calculation, and the practical and simple calculation formula is acquired.

scholarly journals Ductility Estimation of Concrete Beams Longitudinally Reinforced with Hybrid FRP-Steel Bars

2022 ◽  
Author(s):  
Rendy Thamrin ◽  
Zaidir Zaidir ◽  
Devitasari Iwanda
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Element Model ◽  
Neutral Axis ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Bending Test ◽  
Longitudinal Reinforcement ◽  
Steel Bars ◽  
Hybrid Reinforcement

An experimental study was carried out to evaluate the ductility of reinforced concrete beams longitudinally reinforced with hybrid FRP-Steel bars. The specimens were fourteen reinforced concrete beams with and without hybrid reinforcement. The test variables were bars position, the ratio of longitudinal reinforcement, and the type of FRP bars. The beams were loaded up to failure using a four-point bending test. The performance of the tested beams was observed using the load-deflection curve obtained from the test. Numerical analysis using the fiber element model was used to examine the growth of neutral axis depth due to the effect of test variables. The neutral axis curves were then used to further estimate the neutral axis angle and neutral axis displacement index. The test results show that the position of the reinforcement greatly influences the flexural behavior of the beam with hybrid reinforcement. It was observed from the test that the flexural capacity of beams with hybrid reinforcement is 4% to 50% higher than that of the beams with conventional steel bars depending on bars position and the ratio of longitudinal reinforcement. The ductility decreases as the hybrid reinforcement ratio (Af/As) increases. This study also showed that a numerical model developed can predict the flexural behavior of beams with hybrid reinforcement with reasonable accuracy.

scholarly journals Calculation of steel-reinforced concrete beam for instant loading taking into account the non-linearity of the concrete diagram ε-σ

2020 ◽  
Vol 17 (2) ◽  
pp. 85-94
Author(s):  
S. O. Chepilko ◽  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Neutral Axis ◽  
Reinforced Concrete Beams ◽  
System Of Equations ◽  
Nonlinear System Of Equations ◽  
Steel Reinforced Concrete

Issues of calculating steel-reinforced concrete beams are considered taking into account a nonlinear concrete diagram based on the Sargin formula. The nonlinear system of equations for determination of curvature and neutral axis, which is solved numerically, is written in explicit form. Explicit expressions for determination of other calculated quantities needed for design of steel-reinforced concrete beams are derived. Numerical examples are given. The analysis of accounting nonlinearity in comparison with the linear calculation is carried out.

Calcul de la rigidité de torsion des poutres en béton armé fissurées en flexion

1996 ◽  
Vol 23 (6) ◽  
pp. 1190-1198 ◽  
Author(s):  
Naceur Eddine Hannachi ◽  
Bernard Fouré
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Torsional Stiffness ◽  
Longitudinal Reinforcement ◽  
Shape Stability ◽  
Simultaneous Influence ◽  
Small Torque ◽  
Good Agreement

This paper proposes a method to calculate the torsional stiffness of reinforced concrete beams with section of any shape, in a cracked state due to bending, subjected to small torque (shape stability problems). The simultaneous influence of the various parameters (shape of the section, state of cracking, longitudinal reinforcement) is taken into account. A series of laboratory tests on beams with hollow, massive, or double-tee thin cross sections gives data to determine semi-empirically some parameters. Calculated and experimental stiffnesses are in rather good agreement. The proposed method fills in a gap in the nonlinear calculation of reinforced concrete. Key words: reinforced concrete, flexural cracking, torsional stiffness, calculation method, nonlinear elasticity, stability.

Studies on Long-Term Deflection of FRP Reinforced Concrete Beams

2013 ◽  
Vol 438-439 ◽  
pp. 811-814 ◽  
Author(s):  
Quan Ji Han ◽  
Hai Tang Zhu ◽  
Hai Bo Cui
Keyword(s):  
Reinforced Concrete ◽  
Influencing Factors ◽  
Calculation Method ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Research Status

The research status and progress, in China and overseas, of long-term deflection of FRP reinforced concrete beams are briefly introduced in this paper. The mechanism, influencing factors and calculation method of long-term deflection of FRP reinforced concrete beams are discussed and summarized. Meanwhile, some advices for long-term deflection research of FRP reinforced concrete beams are proposed.

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).

EFFECT OF CFRP STRIPS BONDING LOCATION ON FLEXURAL CAPACITY AND DUCTILITY OF REINFORCED CONCRETE BEAMS

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Mina Iskander ◽  
Mina Melad ◽  
Mourad Yasser ◽  
Waleed Abdel Rahim ◽  
Amr Mosa ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Traditional Methods ◽  
Flexural Strengthening ◽  
Advanced Composite ◽  
Advanced Composite Materials ◽  
The Impact ◽  
Strength And Ductility

Strengthening reinforced concrete beams using laminate of advanced composite materials has gained ground recently due to its lower cost and simplicity compared to traditional methods. These traditional methods are usually done by either increasing the reinforcement or the beam’s dimensions, which naturally requires formwork, and hinder the structural usage. One of the most impediments of using bonded laminate in strengthening beams is debonding. In flexural strengthening of beams, this debonding occurs via mid-span debonding or end-delamination of the laminate. Herein, ten RC beams were experimentally tested in flexure under three-point loading. The reinforced concrete beams have rectangular cross sections and were strengthened by bonded CFRP strips. Flexural strength and ductility were investigated in order to reveal the impact of changing the CFRP strips’ locations with respect to the beams’ cross section. The CFRP strips were attached to the reinforced concrete beams sides of bottoms. The first configuration is thought to reduce the effect of flexure cracks in the mid-span of the beams, which may delay the deboning of these laminates. In order to anchor the strips, close to the support and eliminate end delamination, CFRP sheets were wrapped at these locations. Based on the proposed configurations, the flexure strength of the beams increased by an average of 40%.

scholarly journals Research of the Residual Bearing Capacity and the Work of Damaged Reinforced Concrete Beams’ Inclined Sections

2020 ◽  
Vol 14 (4) ◽  
pp. 466-472
Author(s):  
Zeljko Kos ◽  
Yevhenii Klymenko ◽  
Kostiantyn Polianskyi ◽  
Andjelko Crnoja
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Strain State ◽  
Concrete Beams ◽  
Numerical Test ◽  
Neutral Axis ◽  
Reinforced Concrete Beams ◽  
Stress Strain ◽  
Software Complex ◽  
Stress Strain State

The article is devoted to studies about the stress-strain state and the residual bearing capacity of inclined sections of reinforced concrete beams with concrete damages in the compressed zone near support areas. The developed method of calculating the bearing capacity of the inclined sections of damaged beams is described. The numerical test of prototypes was performed in the LIRA-CAD 2017 software complex. A comparison of the results of laboratory tests, a numerical experiment and calculation results by the proposed method is shown. It is stressed that with an increase in the area of damage, the bearing capacity decreases. The nature of the change in the stress-strain state under the presence of damage is described. It is pointed out that in the damaged samples, there is an inclination of the neutral axis in the cross section of the element – it tilts, the neutral axis becomes, almost, parallel to the front of the damage.

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