Flexural Analysis of Simply Supported Concrete Beam Reinforced with FRP Bars

2012 ◽  
Vol 182-183 ◽  
pp. 1617-1621
Author(s):  
Hong Chang Qu ◽  
Ling Ling Chen ◽  
Sheng Li Zhang
Keyword(s):  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Test Results ◽  
Simply Supported ◽  
Reinforced Polymer ◽  
Reinforced Beams ◽  
Theoretical Predictions ◽  
Flexural Analysis ◽  
Frp Bars

The purpose of this paper is to experimentally and theoretically study the flexural behavior of concrete beams reinforced with fiber reinforced polymer (FRP) bars. In this research, two series of concrete beams reinforced with GFRP and CFRP were tested up to failure. Beam stiffness was the same for all beams until the appearance of first cracks. Deflection at failure was identical for beams reinforced with GFRP and CFRP bars, but force at failure of CFRP reinforced beams bars was greater. The theoretical analysis for calculating deflections was carried out. The theoretical results were compared to the test results for the simply supported beam deflections, and the theoretical predictions agree well with the test results.

scholarly journals Post-Fire Characteristics of Concrete Beams Reinforced with Hybrid FRP Bars

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1248
Author(s):  
Kostiantyn Protchenko ◽  
Elżbieta Szmigiera
Keyword(s):  
Elevated Temperatures ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Temperature Threshold ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Reinforced Beams ◽  
Strength Capacity ◽  
Fire Characteristics ◽  
Frp Bars

One of the main concerns of experimental and numerical investigations regarding the behavior of fiber-reinforced polymer reinforced concrete (FRP-RC) members is their fire resistance to elevated temperatures and structural performance at and after fire exposure. However, the data currently available on the behavior of fiber-reinforced polymer (FRP) reinforced members related to elevated temperatures are scarce, specifically relating to the strength capacity of beams after being subjected to elevated temperatures. This paper investigates the residual strength capacity of beams strengthened internally with various (FRP) reinforcement types after being subjected to high temperatures, reflecting the conditions of a fire. The testing was made for concrete beams reinforced with three different types of FRP bars: (i) basalt-FRP (BFRP), (ii) hybrid FRP with carbon and basalt fibers (HFRP) and (iii) nano-hybrid FRP (nHFRP), with modification of the epoxy matrix of the rebar. Tested beams were first loaded at 50% of their ultimate strength capacity, then unloaded before being heated in a furnace and allowed to cool, and finally reloaded flexurally until failure. The results show an atypical behavior observed for HFRP bars and nHFRP bars reinforced beams, where after a certain temperature threshold the deflection began to decrease. The authors suggest that this phenomenon is connected with the thermal expansion coefficient of the carbon fibers present in HFRP and nHFRP bars and therefore creep can appear in those fibers, which causes an effect of “prestressing” of the beams.

Concrete Beams Reinforced with GFRP Plates

2017 ◽  
Vol 747 ◽  
pp. 220-225
Author(s):  
Alberto Pedro Busnelli ◽  
Ruben Edgardo López ◽  
Jorge Carlos Adue
Keyword(s):  
Glass Fiber ◽  
Carbon Fibers ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
The World ◽  
Critical Resistance

This is the presentation of the research carried out by the Faculty of Engineering at Universidad Nacional de Rosario on the use of pultruded Glass Fiber Reinforced Polymer (GFRP) plates to increase the flexural strength of reinforced concrete beams.Pultruded plates are the type of elements made of composite materials which are most widely used for this kind of strengthening. Although around the world the material used for these plates is carbon fibers, its high cost prevents its widespread use in our country.One of the aims of our research program is, precisely, to verify whether it is possible to substitute such plates for significantly cheaper glass fiber elements manufactured in Argentina. The test results have proved that this alternative is feasible.What's more, the greater thickness of the glass fiber plates allows the use of additional anchor bolts. These bolts provide the system with post-critical resistance and ductility-characteristics which are absolutely necessary, for example, in structures in seismic areas.

scholarly journals Strengthening Reinforced Concrete Beams with CFRP and GFRP

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mehmet Mustafa Önal
Keyword(s):  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Strength Increase ◽  
Fiber Reinforced ◽  
Flexural Stress ◽  
Four Point Bending ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Reinforced Beams

Concrete beams were strengthened by wrapping the shear edges of the beams twice at 45° in opposite directions by either carbon fiber reinforced polymer (CFRP) or glass fiber reinforced polymer (GFRP). The study included 3 CFRP wrapped beams, 3 GFRP wrapped beams, and 3 control beams, all of which were 150×250×2200 mm and manufactured with C20 concrete and S420a structural steel at the Gazi University Technical Education Faculty labs, Turkey. Samples in molds were cured by watering in the open air for 21 days. Four-point bending tests were made on the beam test specimens and the data were collected. Data were evaluated in terms of load displacement, bearing strength, ductility, and energy consumption. In the CFRP and GFRP reinforced beams, compared to controls, 38% and 42%, respectively, strength increase was observed. In all beams, failure-flexural stress occurred in the center as expected. Most cracking was observed in the flexural region 4. A comparison of CFRP and GFRP materials reveals that GFRP enforced parts absorb more energy. Both materials yielded successful results. Thicker epoxy application in both CFRP and GFRP beams was considered to be effective in preventing break-ups.

Deflection Prediction of FRP-Strengthened Reinforced Concrete Beams

2011 ◽  
Vol 243-249 ◽  
pp. 621-624
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo
Keyword(s):  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Test Results ◽  
Structural Members ◽  
Modified Model ◽  
Reinforced Polymer ◽  
Service Load ◽  
Good Agreement

Bonding fiber reinforced polymer (FRP) laminates to the tension face of RC members has been proven to be an effective method to improve the flexural strength. However, structural members are not only needed to have adequate strength, but also to have adequate performance of deformation at service load levels. To evaluate the deflection of externally FRP-strengthened RC beams, a total of 18 RC beams, including 16 beams strengthened with CFRP laminate under different preload levels and 2 control beams, were tested. Based on the assumption that the section of the beam behaves a tri-linear moment-curvature response characterized by pre-crack stage, post-crack stage and failure stage and the test results, this paper presents a modified model to evaluate the deflection of CFRP-strengthened RC beams. The present modified model was verified by the similar test results, and shows a good agreement with the test results.

NUMERICAL ANALYSIS OF CONCRETE BEAM REINFORCED WITH GLASS FIBER REINFORCED POLYMER BARS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Osama A. Mohamed ◽  
Rania Khattab
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Reinforcing Bars ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Frp Bars

The use of fiber reinforced polymer (FRP) bars to reinforce concrete beams has received significant attention in the past decade due to their corrosion resistance, high tensile strength, and excellent non-magnetic properties. Glass FRP (GFRP) reinforcing bars have gained popularity due to the relatively lower cost compared to carbon FRP (CFRP) bars. In this study, sixteen concrete beam finite element models were created using the finite element computer program ANSYS to perform linear and non-linear analyses. Twelve beams were longitudinally reinforced with GFRP bars, while the remaining four beams were reinforced with conventional steel bars as control specimens. In terms of mechanical properties, FRP reinforcing bars have lower modulus of elasticity compared to conventional reinforcing steel and remain linear elastic up to failure. This leads to lack of plasticity and a brittle failure of beams reinforced with FRP bars. The objective of this study is to investigate flexural behavior of concrete beams reinforced with GFRP reinforcing bars. Some of the parameters incorporated in the numerical analysis include longitudinal reinforcement ratio and compressive strength of concrete, both of which affect the flexural capacity of beams. It is shown in this study that replacement of traditional reinforcing steel reinforced bars by GFRP bars significantly decreases mid-span deflection and increases ultimate load. The strain distribution along GFRP longitudinal reinforcing bars is totally different from that of traditional steel bars.

scholarly journals Shear Behavior in Beams Reinforced with Glass-Fiber Reinforced Polymer Bars (GFRPB) without stirrups

2021 ◽  
Vol 9 (1) ◽  
pp. 72-78
Author(s):  
Osama Daoud ◽  
Ahmed Fadul
Keyword(s):  
Shear Strength ◽  
Glass Fiber ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Glass Fiber Reinforced Polymer ◽  
Shear Span ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced

The behavior and shear strength of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars was investigated. Total of six reinforced concrete beams without stirrups were constructed and tested up to failure. The beams measured 1400 mm long, 150 mm wide and 300 mm deep and were tested in two-points bending with constant shear span 350 mm in all tested beams, and shear span to depth ratio a/d 1.37. The test variable was the reinforcement ratio. The test beams included three beams designed as tension control (T.C) with GFRP bars, three beams designed as compression control (C.C) with GFRP bars. The test results were compared with predictions provided by ACI 440.1R-15 design guideline and proposed equations in the literature. The test results indicated that the relatively low modulus of elasticity of FRP bars resulted in reducing shear strength. In addition, shear strength provided by ACI 440.1R-15 guideline underestimate shear strength capacity in which proposed equations in the literature had given better prediction than ACI 440.1R-15. The failure mode in T.C beams is diagonal tension by bond failure not by rupture of FRP and C.C beams is shear compression by crushing of the web in extreme fiber.  

Experimental Study on Flexural Behavior of CFRP Reinforced Pre-Stressed Concrete Beams with Initial Cracks

2020 ◽  
Vol 984 ◽  
pp. 230-238
Author(s):  
Yun Yan Liu ◽  
Ying Fang Fan
Keyword(s):  
Ultimate Load ◽  
Concrete Beams ◽  
Flexural Behavior ◽  
Test Results ◽  
Bending Tests ◽  
Reinforced Beams ◽  
Beam Section ◽  
Non Destructive ◽  
Initial Cracks ◽  
Good Agreement

In order to explore the flexural behavior of CFRP reinforced pre-stressed concrete (PC) beams with initial cracks, 6 pre-tensioned beams were manufactured. Then the beams were pre-loaded to crack with 40% and 60% ultimate load respectively, and the beams were strengthened by CFRP under the conditions of load holding and fully unloaded. After that, the four-points bending tests were performed, and beam section strains, flexural capacities and cracks were analyzed. The results demonstrate that the ultimate load of CFRP reinforced beams increased by 10%~18%, and the ultimate loads of CFRP reinforced load holding beams were 3% and 6% lower than that of CFRP reinforced non-destructive beam, and the inhibiting effect of CFRP on cracks was weakened, the hysteresis strains should be considered for them. In this paper, the fiber hysteresis strains were calculated by the method of full section decompression moment, and the flexural capacities of CFRP reinforced PC beams were calculated, which are in good agreement with the test results.

Comparative Study on Deflection Calculation for Concrete Flexural Members with Fiber Reinforced Polymer Reinforcement

2011 ◽  
Vol 183-185 ◽  
pp. 1979-1983
Author(s):  
Jiang Yong Cai ◽  
Xi Bo Zhou ◽  
Xiong Jia ◽  
Yan Tao He
Keyword(s):  
Concrete Beams ◽  
Reinforce Concrete ◽  
Fiber Reinforced Polymer ◽  
New Method ◽  
Flexural Members ◽  
Modified Method ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Frp Bars ◽  
Good Agreement

The application and development of FRP bars for reinforce concrete structures necessitates the need for either adopt the current code method or exploiting a new design one to account for the properties of FRP materials. The method for predicting deflection of concrete beams with FRP bars in ACI440 is based on the method for that with steel bars in ACI318. Similarly, a modified method based on GB50010 is proposed in this paper to estimate deflection of concrete beams with FRP bars. Furthermore, the new method, together with ACI318, ACI440 and GB50010 ones, are verified by nine test beams in three existing experiment and show a good agreement with the experimental data. Simultaneously, the new method is also proved to be of the most precise and accurate one and indicates the potential of the method to estimate deflection in Chinese code system.

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