Modeling the tensile steel reinforcement strain in RC-beams subjected to cycles of loading and unloading

2016 ◽  
Vol 126 ◽  
pp. 92-105 ◽  
Author(s):  
Tengfei Xu ◽  
Arnaud Castel ◽  
R. Ian Gilbert ◽  
Angus Murray
Keyword(s):  
Steel Reinforcement ◽  
Rc Beams ◽  
Loading And Unloading ◽  
Reinforcement Strain

Contribution à l'étude du renforcement en cisaillement des poutres en béton armé à l'aide de matériaux composites avancés

2005 ◽  
Vol 32 (2) ◽  
pp. 339-351 ◽  
Author(s):  
Abdelhak Bousselham ◽  
Omar Chaallal
Keyword(s):  
Experimental Investigation ◽  
Resistance Mechanism ◽  
Steel Reinforcement ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Frp Composites ◽  
Frp Composite ◽  
Fibre Reinforced Polymer ◽  
The Subject ◽  
Transverse Steel

This paper presents results of an investigation on the shear strengthening of reinforced concrete (RC) beams with externally applied fibre reinforced polymer (FRP) composites. The first part of the study reviews and synthesizes the state of the art in the subject. Also, the requirements and recommendations specified in the Canadian CSA S806-02 standards, the American ACI-440 guidelines, as well as the European fib TG9.3 recommendations are compared with the test results reported in the literature so far. This part of the study indicates that the major parameters involved in the behaviour of RC beams strengthened in shear with FRP were not fully investigated. This can explain the observed discrepancies between the resistance values predicted by the codes and guidelines, and those obtained by tests. This has been the main impetus to carry out an experimental investigation, which is the subject of the second part of this paper. The objective of this experimental investigation was to study the influence of the following parameters on the performance of RC beams strengthened in shear with FRP composites: (i) the FRP ratio, (ii) the transverse steel reinforcement ratio, and (iii) the type of beam (deep versus slender). Results clearly showed the interaction between the FRP composite and the internal transverse steel reinforcement in the shear resistance mechanism. Results also showed the influence of the type of beam on the gain due to FRP on the carrying capacity of the beam.Key words: shear, reinforcement, concrete, composites, experimental, parameters.

NONLINEAR FINITE ELEMENT ANALYSIS OF FRP STRENGTHENED RC BEAMS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Prabin Pathak ◽  
Y. X. Zhang
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Experimental Studies ◽  
Material Model ◽  
Element Model ◽  
Steel Reinforcement ◽  
Elastic Model ◽  
Fe Model ◽  
Rc Beams ◽  
Element Analysis

A simple, accurate and efficient finite element model is developed in ANSYS for numerical modelling of the nonlinear structural behavior of FRP strengthened RC beams under static loading in this paper. Geometric nonlinearity and material non-linear properties of concrete and steel rebar are accounted for this model. Concrete and steel reinforcement are modelled using Solid 65 element and Link 180 element, and FRP and adhesive are modelled using Shell 181element and Solid 45 element. Concrete is modelled using Nitereka and Neal’s model for compression, and isotropic and linear elastic model before cracking with strength gradually reducing to zero after cracking for tension. For steel reinforcement, the elastic perfectly plastic material model is used. FRPs are assumed to be linearly elastic until rupture and epoxy is assumed to be linearly elastic. The new FE model is validated by comparing the computed results with those obtained from experimental studies.

Analysis on Hysteretic Strain of Load-Carrying Strengthened RC Beams

2013 ◽  
Vol 351-352 ◽  
pp. 1337-1340
Author(s):  
Chun Xia Li ◽  
Zhi Sheng Ding ◽  
Shi Lin Yan ◽  
Jun Ming Chen
Keyword(s):  
Steel Corrosion ◽  
Linear Interpolation ◽  
Neutral Axis ◽  
Reinforcement Ratio ◽  
Experimental Result ◽  
Rc Beams ◽  
Load Carrying ◽  
Axis Position ◽  
Loading And Unloading ◽  
Current Code

Based on the reported experimental result of unchanged neutral axis position during loading and unloading, the theoretic formula of hysteretic strain after unloading is obtained for different loading condition. The reinforcement ratio is the most important factor influencing the hysteretic strain, relative unloading degree secondly, and strength of concrete and steel influencing weakly. The simplified formula of hysteretic strain is presented by a series of regression, which replacing linear interpolation between neighboring reinforcement ratios in the current code. The calculated value is close to that from the current code for the regular reinforcement ratio, but comparatively higher for short reinforcement ratio caused by steel corrosion.

scholarly journals Long-term Deflections of Hybrid GFRP/Steel Reinforced Concrete Beams under Sustained Loads

2020 ◽  
Vol 6 ◽  
pp. 1-11
Author(s):  
Phan Duy Nguyen ◽  
Vu Hiep Dang ◽  
Ngoc Anh Vu ◽  
Polikutin Aleksei Eduardovich
Keyword(s):  
Reinforced Concrete ◽  
Steel Reinforcement ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Rc Beams ◽  
Climate Conditions ◽  
Glass Fiber Reinforced ◽  
Sustained Loads

One of the solutions to improve the flexural behavior of Glass fiber reinforced polymer (GFRP) reinforced concrete (RC) beams is the addition of tensile longitudinal steel reinforcement. The numerous studies to date on hybrid GFRP/steel RC elements have mainly focused on the static and short-term responses, very little work has been done regarding the long-term performance. This paper presents experimental results of time-dependent deflections of cracked GFRP and hybrid GFRP/steel RC beams during a 330-day-period in natural climate conditions. Three hybrid GFRP/steel and one GFRP RC beams with dimensions 100×200×2000 mm were tested in four-point bending. Different steel reinforcement ratios were used to evaluate the effect of the steel reinforcement on the long-term behavior of the beams. Experimental results show that the immediate deflections are inversely proportional to the additional steel reinforcement. With the same initial instantaneous deflection, the total deflection increases when increasing the steel reinforcement ratio. Also, temperature (T) and relative humidity (RH) significantly affect the long-term deflection of the tested beams. The measured long-term deflections were found to be in good agreement with the theoretical values calculated from the proposed method. However, there was an overestimation when using ACI 440.1R-15 or CSA-S806-12 procedures.

scholarly journals Experimental and Theoretical Analysis of Cracking Moment of Concrete Beams Reinforced with Hybrid Fiber Reinforced Polymer and Steel Rebars

2021 ◽  
Vol 6 (4) ◽  
pp. 222-234
Author(s):  
Hiep Dang Vu ◽  
Duy Nguyen Phan
Keyword(s):  
Nonlinear Behavior ◽  
Steel Reinforcement ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Positive Effects ◽  
Reinforced Polymer ◽  
Hybrid Reinforcement ◽  
Steel Rebars

This study aims at experimentally and theoretically investigating the cracking moment (Mcrc) of hybrid Fiber Reinforced Polymer (FRP)/steel Reinforced Concrete (RC) beams. Six hybrid Glass FRP (GFRP)/steel and three GFRP RC beams with various GFRP and steel reinforcement ratios are tested in four-point bending scheme. Experimental results indicate that both GFRP and steel rebars affect Mcrc, but the effect of steel reinforcement is more significant. When the steel reinforcement ratio increases to 1.17%, Mcrc goes up to 15.9%, while the same value for GFRP is only 9.7%. An analytical method is proposed based on the plain section assumption and nonlinear behavior of materials for estimating Mcrc. The proposed model shows a good agreement with the experimental data conducted in this study and collected from the literature. The results of the parametric study give evidence of the positive effects of hybrid reinforcement ratios and elastic modulus of FRP on Mcrc of hybrid RC beams.

Behavior of RC Beams Strengthened by CFRP and Steel Rope under Frequent Impact Load

2018 ◽  
Vol 1 (1) ◽  
pp. 30-42
Author(s):  
Muataz Ali ◽  
◽  
Yaseen Saleh ◽  
Luna Al Hasani ◽  
Ammar Khazaal ◽  
...  
Keyword(s):  
Impact Load ◽  
Rc Beams ◽  
Steel Rope
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