Environmental Fatigue and Static Behavior of RC Beams Strengthened with Carbon-Fiber-Reinforced Polymer

2004 ◽  
Vol 8 (3) ◽  
pp. 211-218 ◽  
Author(s):  
Catalin Gheorghiu ◽  
Pierre Labossière ◽  
Alexandre Raı⁁che
2019 ◽  
Vol 9 (8) ◽  
pp. 923-930
Author(s):  
Ning Zhuang ◽  
Junzhou Chen ◽  
Miao Zheng ◽  
Da Chen

Flexural capacity of RC beams gets significant improvement with externally bonded Carbon Fiber-reinforced Polymer (CFRP) sheet. The anchorage system is a valid means to restrain or delay debonding failure caused by stress concentration at the ends of CFRP sheets. In this paper, four RC beams, measuring 150 × 200 × 1900 mm, were examined under four-point bending test. One beam was applied for contrast. And other three were CFRP strengthened with no anchorage, CF anchors (carbon fiber anchors) and U-wraps (U-shaped CFRP wraps). The primary purpose of the experiment was to validate the effectiveness of CF anchors and U-wraps in improving the flexure character of beams strengthened with CFRP sheets. The experimental results revealed that the strengthened beams using anchorage systems performed remarkably in beam ductility, flexural capacity, load-deflection response and failure mode compared with the contrast beam. The anchorage systems were more effective and necessary to enhance the flexural behavior of beams as using CFRP laminates for flexural strengthening.


2021 ◽  
pp. 136943322110499
Author(s):  
Riyam J Abed ◽  
Mohammed A Mashrei ◽  
Ali A Sultan

The externally bonded reinforcement on grooves (EBROG) method is increasingly recognized as an alternative strengthening method that can overcome the debonding problem. This study aims to experimentally investigate the effectiveness of EBROG as compared to the conventional externally bonded reinforcement (EBR) method in strengthening reinforced concrete (RC) beams. Twelve RC beams have been tested under four point load bending. One of these beams has been designated as a reference beam, seven beams have been strengthened with carbon fiber reinforced polymer (CFRP) sheets, and four beams have been strengthened with CFRP laminates using EBROG or EBR methods. The effect of CFRP type, number of layers, as well as the type of strengthening methods on the flexural performance have been also investigated. The load, deflection, stiffness, and failure modes were recorded and discussed intensively. Overall, test results indicated that the flexural strength and stiffness of the strengthened specimens using EBR or EBROG methods increased compared to the control beam, where the increase in the load carrying capacity of beams strengthened using the EBR method ranged between 24.8 and 48.2% and by the EBROG method ranged between 31.7 and 76.7% of the control beam. The most interesting result obtained is that the failure mode of beams has been changed from debonding of CFRP material to rupture of CFRP in some samples strengthened by EBROG, which demonstrates the superior behavior of this strengthening technique as compared to the traditional strengthening using EBR.


2016 ◽  
Vol 845 ◽  
pp. 154-157
Author(s):  
Sri Tudjono ◽  
Himawan Indarto ◽  
Monica Devi

Shear reinforcement for retrofitting an RC beam using unidirectional Carbon Fiber Reinforced Polymer (CFRP) woven can only be applied on the beam’s body below the concrete floor slab. Thus, it cannot fully curb like the way stirrups do, in which it will affect the shear capacity. The CFRP can only be ‘n’or ‘u’ shaped, taking into consideration the direction of shear force. Herein, the experimental study of the shear capacity ofshear capacity the beam strengthened by FRP is carried out.shear capacity The beams are RC beams of width 150 mm, height 300 mm, span of 1000 mm, f'c = 26 MPa having 2 bar of 19 mm diameter (fy = 403.65 MPa) and stirrups 6 mm diameter of 250 mm spacing (fy=375 MPa). The shear capacity measured is then compared with the shear capacity calculated using ACI 440. The result shows that the shear capacity measured from experiment is greater than the shear capacity calculated by ACI 440. Also, theshear capacity of RC beam with CFRP reinforcement n shape is greater than u shape.


2015 ◽  
Vol 754-755 ◽  
pp. 432-436
Author(s):  
Ibrahim H. Alfahdawi ◽  
S.A. Osman

When reinforced concrete (RC) beams are found deficient in flexure, and fails in shear capacity after shear strengthening, the need to use new technique for flexure strengthening become important. Over the years, there are many experimental studies had been carried out with this technique of strengthening, and finding from other researchers have proved to be effective and successful. In this study, the behavior of flexure in RC beams strengthened with carbon fiber reinforced polymer (CFRP) were investigated. ANSYS11 software package of finite element method was use to simulate two models of RC beams with different parametric study such as (i) effect of grade of concrete, (ii) number of layers of CFRP strips, (iii) effect of steel stirrups and CFRP strips and (iv) longitudinal reinforcement yield stress. The results show that for beams strengthened with CFRP has increased in capacity load up to 32.8%. In general, good agreement between the FE solution and the available experimental results has been obtained.


Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 158
Author(s):  
Athasit Sirisonthi ◽  
Phongthorn Julphunthong ◽  
Panuwat Joyklad ◽  
Suniti Suparp ◽  
Nazam Ali ◽  
...  

An experimental program was conducted to ascertain the efficiency of Carbon Fiber Reinforced Polymer (CFRP) in enhancing the flexural response of hollow section reinforced concrete (RC) beams. Nine beams were tested under four-point bending in three groups. Beams were categorized to reflect the presence or configuration of the CFRP sheet. Each group consisted of three beams: one with a solid section, one with a square 50×50  mm × mm opening and 1 with 100×100  mm × mm opening. Beams in 1st group were tested in as-built conditions. Beams in the 2nd group were strengthened with a single CFRP sheet bonded to their bottom sides. Configuration of CFRP sheet was altered to U-shape applied to the tension side of 3rd group beams. The inclusion of openings, regardless of their size, did not result in degradation of ultimate load and corresponding deflections. However, cracking loads were found to decline as the opening size increased. Regardless of the opening size and CFRP configuration, ultimate loads of beams increased with the application of CFRP. However, this improvement was limited to the debonding and rupture of CFRP in group 2 and 3 beams, respectively. A comparison in the behavior of group 2 and 3 beams revealed that the application of the U-shape CFRP sheet yielded better flexural performance in comparison with the flat-CFRP sheet bonded to the bottom of beams. In the end, In order to further evaluate the economic and performance benefits of these beams, the cost-benefit analysis was also performed. The analysis showed that the feasibility of the hollow section RC beams is more than the solid section RC beams.


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