scholarly journals Behavior of concrete beams reinforced with FRP during bending

2021 ◽  
Vol 263 ◽  
pp. 02052
Author(s):  
Igor Gorbunov ◽  
Vladimir Kakusha
Keyword(s):  
Crack Formation ◽  
Concrete Beams ◽  
Bending Moment ◽  
Bending Stiffness ◽  
Fiber Reinforced Polymer ◽  
Strain Behavior ◽  
Linear Elastic ◽  
Reinforced Polymer ◽  
Glass Frp ◽  
Frp Bars

Article describes methods and results of experimental research for strain behavior, crack formation and fracture of concrete beams reinforced with fiber reinforced polymer (FRP) bars during bending moment action. 18 beams (3+3 series) reinforced with glass FRP (GFRP) and basalt (BFRP) 6, 10 and 14 mm in diameter were tested. Deflection in the middle of the beam, concrete and bars strain and ultrasonic transmission time for 4 routes were measured during tests besides visual inspection. Main crack formation occurred at 8-20% of the ultimate load for all beams. Crack formation was transition border to linear (elastic) straining at low bending stiffness. More than 15 times decrease in bending stiffness was seen for beam reinforced with two types of bars 6 mm in diameter compared to initial values. Existence of main cracks and major deflections is not allowed during design of bending elements. However small bending stiffness at linear elastic straining is a positive factor in case of «hard» loading and impact (pulsed) loading. It is possible to prevent structures collapse and people deaths at impact loading and cyclic «hard» loading by permitting crack formation in load bearing structures.

Characterization of combined longitudinal and transverse FRPs for strengthening concrete columns

2020 ◽  
Vol 47 (6) ◽  
pp. 718-728
Author(s):  
Pedram Sadeghian ◽  
Brandon Fillmore
Keyword(s):  
Bending Moment ◽  
Concrete Columns ◽  
Fiber Reinforced Polymer ◽  
Near Surface ◽  
Strain Behavior ◽  
Reinforced Polymer ◽  
Concrete Cylinders ◽  
Near Surface Mounted ◽  
Glass Frp

This paper presents the results of a study on the characterization of combined longitudinal near-surface-mounted (NSM) fiber-reinforced polymer (FRP) bars and transverse FRP wraps for strengthening concrete columns. A total of 21 concrete cylinders were prepared, strengthened, and tested to characterize the performance of the strengthening system. Three arrangements of glass FRP (GFRP) bars were mounted in surface grooves, and unidirectional basalt FRP (BFRP) composite was used to wrap the specimens. It was shown that the wrapping system effectively prevented premature failures of the NSM bars and extended the contribution of the bars from a mean of 17.5% in the NSM specimens to a mean of 27.7% in the specimens strengthened with the combined NSM and transverse FRPs. An analytical model was also presented to predict the load–strain behavior and the effect of combined axial load and bending moment.

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.

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.

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.

Deflection and Crack-Width Prediction of Partially Boned CFRP Concrete Beams

2010 ◽  
Vol 168-170 ◽  
pp. 2182-2185
Author(s):  
Yu Deng ◽  
Jiong Feng Liang
Keyword(s):  
Crack Width ◽  
Concrete Beams ◽  
Experimental Results ◽  
Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Low Modulus ◽  
Monotonic Loads ◽  
Frp Bars ◽  
Unbonded Length ◽  
Good Agreement

Concrete beams reinforced with fiber reinforced polymer(FRP)bars exhibit large deflections and crack widths as compared to concrete beams reinforced with steel due to the low modulus of elasticity of FRP. Consequently,in many cases,serviceability requirements may govern the design of such members. This paper describes six partial bonded concrete beams prestressed with CFRP tendons are tested under monotonic loads. deformation and crack width of this kind of beams with varying unbonded length are systematically investigated. The predictions of the 《Code for Design of Concrete Structures》（GB50010－2002）equations are compared with the experimental results obtained by testing six partial bonded concrete beams prestressed with CFRP tendons. Good agreement was shown between the theoretical and the experimental results.

scholarly journals Reinforced Concrete Beams with Carbon-Fiber-Reinforced Polymer Bars—Experimental Study

Fibers ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 99 ◽  
Author(s):  
Chris G. Karayannis ◽  
Parthena-Maria K. Kosmidou ◽  
Constantin E. Chalioris
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Concrete Beams ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Cracking Behavior ◽  
Reinforced Polymer ◽  
Frp Bars

Innovative reinforcement as fiber-reinforced polymer (FRP) bars has been proposed as alternative for the substitution of the traditional steel bars in reinforced concrete (RC) structures. Although the advantages of this polymer reinforcement have long been recognised, the predominantly elastic response, the reduced bond capacity under repeated load and the low ductility of RC members with FRP bars restricted its wide application in construction so far. In this work, the behavior of seven slender concrete beams reinforced with carbon-FRP bars under increasing static loading is experimentally investigated. Load capacities, deflections, pre-cracking and after-cracking stiffness, sudden local drops of strength, failure modes, and cracking propagation have been presented and commented. Special attention has been given in the bond conditions of the anchorage lengths of the tensile carbon-FRP bars. The application of local confinement conditions along the anchorage lengths of the carbon-FRP bars in some specimens seems to influence their cracking behavior. Nevertheless, more research is required in this direction. Comparisons of experimental results for carbon-FRP beams with beams reinforced with glass-FRP bars extracted from recent literature are also presented and commented. Comparisons of the experimental results with the predictions according to ACI 440.1R-15 and to CSA S806-12 are also included herein.

Finite element modeling of concrete beams reinforced with basalt FRP bars

2019 ◽  
Author(s):  
Jordan Carter ◽  
Aikaterini Genikomsou
Keyword(s):  
Finite Element ◽  
Concrete Beams ◽  
Three Dimensional ◽  
Basalt Fiber ◽  
Mesh Size ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Tension And Compression ◽  
Frp Bars

<p>Fiber-reinforced polymer (FRP) bars can replace conventional steel reinforcing rebars to prevent from corrosion in reinforced concrete structures exposed to highly corrosive environments. In this contribution, three tested concrete beams reinforced with BFRP (Basalt Fiber Reinforced Polymer) bars are analyzed using three-dimensional finite element methods. In the numerical analyses, concrete is modeled as nonlinear using plasticity and damage principles, while BFRP is modeled as linear elastic material. The main focus of this research is to present the calibration process that should take place prior to any parametric studies. This calibration suggests that the concrete model should be regularized using a characteristic length and material post-yield fracture energies in both tension and compression to provide mesh-size independent results. The numerical results are compared to the test results with regard to failure load and cracking.</p>

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.

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