Theoretical Investigation of Concrete Beams Reinforced with Steel and Fiber Reinforced Polymer Bars

2017 ◽  
Author(s):  
Besian Sianani ◽  
Metin Hakan Severcan ◽  
Ilker Fatih Kara
2019 ◽  
Vol 7 (1) ◽  
pp. 30-34
Author(s):  
A. Ajwad ◽  
U. Ilyas ◽  
N. Khadim ◽  
Abdullah ◽  
M.U. Rashid ◽  
...  

Carbon fiber reinforced polymer (CFRP) strips are widely used all over the globe as a repair and strengthening material for concrete elements. This paper looks at comparison of numerous methods to rehabilitate concrete beams with the use of CFRP sheet strips. This research work consists of 4 under-reinforced, properly cured RCC beams under two point loading test. One beam was loaded till failure, which was considered the control beam for comparison. Other 3 beams were load till the appearance of initial crack, which normally occurred at third-quarters of failure load and then repaired with different ratios and design of CFRP sheet strips. Afterwards, the repaired beams were loaded again till failure and the results were compared with control beam. Deflections and ultimate load were noted for all concrete beams. It was found out the use of CFRP sheet strips did increase the maximum load bearing capacity of cracked beams, although their behavior was more brittle as compared with control beam.


2006 ◽  
Vol 324-325 ◽  
pp. 995-998
Author(s):  
Cheol Woo Park ◽  
Jong Sung Sim

Even though the application of fiber reinforced polymer (FRP) as a concrete reinforcement becomes more common with various advantages, one of the inherent shortcomings may include its brittleness and on-site fabrication and handling. Therefore, the shape of FRP products has been limited only to a straight bar or sheet type. This study suggests a new technique to use glass fiber reinforced polymer (GFRP) bars for the shear reinforcement in concrete beams, and investigates its applicability. The developed GFRP stirrup was used in the concrete instead of ordinary steel stirrups. The experimental program herein evaluates the effectiveness of the GFRP stirrups with respect to different shear reinforcing ratios under three different shear span-to-depth testing schemes. At the same shear reinforcing ratio, the ultimate loads of the beams were similar regardless the shear reinforcing materials. Once a major crack occurs in concrete, however, the failure modes seemed to be relatively brittle with GFRP stirrups. From the measured strains on the surface of concrete, the shear stresses sustained by the stirrups were calculated and the efficiency of the GFRP stirrups was shown to be 91% to 106% depending on the shear span-to-depth ratio.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mehmet Mustafa Önal

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.


2010 ◽  
Vol 163-167 ◽  
pp. 3701-3706 ◽  
Author(s):  
Tian Lai Yu ◽  
Li Yuan Zhang

Friction loss is an important component of the calculation of prestressing loss for external prestress strengthening technology. Unfortunately, the test data of relevant curvature friction and wobble coefficients is scarce, especially for beams strengthened by external prestressing Carbon Fiber-Reinforced Polymer (CFRP) tendons. Through the experiment of 12 concrete beams strengthened by external prestressing CFRP tendons, this study attempts to discuss the friction loss algorithm and the reasonable value of friction coefficient. The test results demonstrated that traditional friction loss algorithm for prestressed steel tendons is also suit to external prestressing CFRP tendons, but the value of curvature and wobble coefficients should be determined by different types of CFRP tendons and saddle design. What is more, aiming at the domestic production of CFRP tendons and the adopted special saddle design in this paper, the curvature friction coefficient is 0.263 and the wobble coefficient is 0.0067 at the deviator. Results of the research provide a reference for external prestress strengthening design with CFRP tendons.


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