Flexural Behavior of Reinforced Concrete (RC) Beams with Externally Bonded (EB) Carbon Fiber Reinforced Polymer (CFRP) Sheets

InCIEC 2013 ◽  
2014 ◽  
pp. 637-648
Author(s):  
M. N. Nurbaiah ◽  
A. H. Hanizah ◽  
I. Nor Farhana
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Carbon Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Externally Bonded

Flexural behavior of reinforced concrete beams strengthened by carbon fiber reinforced polymer using different strengthening techniques

2021 ◽  
pp. 136943322110499
Author(s):  
Riyam J Abed ◽  
Mohammed A Mashrei ◽  
Ali A Sultan
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Control Beam ◽  
Reinforced Polymer ◽  
Externally Bonded ◽  
Carbon Fiber Reinforced

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.

Externally bonded carbon fiber–reinforced polymer composites for seismic retrofit of reinforced concrete coupling beams designed according to old codes

2018 ◽  
Vol 22 (6) ◽  
pp. 1412-1425 ◽  
Author(s):  
Sara Honarparast ◽  
Georges El-Saikaly ◽  
Omar Chaallal
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Polymer Composites ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Externally Bonded ◽  
Carbon Fiber Reinforced

A large number of existing buildings have seismic-resistant systems designed according to old code provisions. These structural systems exhibit non-ductile behavior and can present a significant risk in the case of a moderate or significant seismic event. Reinforced concrete–coupled shear walls designed to old codes and standards are among those deficient structures that need to be seismically upgraded. This article aims to investigate a new retrofitting and upgrading method using externally bonded carbon fiber–reinforced polymer composites for existing or/and damaged reinforced concrete coupling beams that can improve the seismic performance of them during earthquakes. To this end, an experimental test was conducted to evaluate the seismic behavior of two identical reinforced concrete–coupled shear wall specimens under reverse cyclic loading. To simulate the old existing building, the specimens were designed and constructed according to the old 1941 National Building Code of Canada with a conventionally reinforced coupling beam. One of the specimens was tested as a control, and the other was strengthened using externally bonded carbon fiber–reinforced polymer composites to evaluate the improvement in its seismic performance. Results show that the retrofit using externally bonded carbon fiber–reinforced polymer resulted in significant enhancement in strength and energy dissipation capacity compared to the conventionally reinforced coupling beam from the control specimen. In addition, externally bonded carbon fiber–reinforced polymer sheets resulted in much improved hysteretic and ductile behavior and in lesser strength and stiffness degradation.

Flexural experimental study on reinforced concrete beams strengthened with carbon fiber-reinforced polymer laminates using anchorage systems

2019 ◽  
Vol 9 (8) ◽  
pp. 923-930
Author(s):  
Ning Zhuang ◽  
Junzhou Chen ◽  
Miao Zheng ◽  
Da Chen
Keyword(s):  
Carbon Fiber ◽  
Fiber Reinforced Polymer ◽  
Bending Test ◽  
Carbon Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Flexural Capacity ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

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.

Exploratory experimental study on flexural behavior of CFRP-reinforced concrete beams subjected to acidic loading effect

2018 ◽  
Vol 21 (14) ◽  
pp. 2184-2197 ◽  
Author(s):  
Hai-Yang Luan ◽  
Ying-Fang Fan ◽  
An Chen ◽  
Shi-Yi Zhang
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

This article presents an exploratory study on the flexural behavior of carbon fiber–reinforced polymer–reinforced concrete beams subjected to acidic loading effect. To this end, an artificial acid rain with a pH level of 1.5 was prepared by mixing sulfate and nitric acid solutions. Eight reinforced concrete beams with/without carbon fiber–reinforced polymer applications were constructed and conditioned using the artificial acid rain. During conditioning, bending loads were applied to the top surfaces of the beams to simulate the acidic loading action. Three carbon fiber–reinforced polymer reinforcement schemes (corrosion reinforcement, reinforcement corrosion, and cracking reinforcement) were considered. After conditioning, the length and quantity of initial cracks in the beams were recorded. A combined ultrasonic–rebound method was then adopted to measure the strength and corrosion depth of the concrete and evaluate the beams’ integrity. Next, four-point bending tests were conducted to study the beams’ flexural behavior. It can be concluded that all beams deteriorated with the increase of the corrosion time. Carbon fiber–reinforced polymer–reinforced concrete beams performed better than normal reinforced concrete beams under the acidic loading effect. The initial cracks can influence the flexural behavior of carbon fiber–reinforced polymer–reinforced concrete beams.

scholarly journals Reinforced Concrete Corbel Strengthened Using Carbon Fiber Reinforced Polymer (CFRP) Sheets

2019 ◽  
Vol 3 (1) ◽  
pp. 26
Author(s):  
Rafael Souza ◽  
Leandro Trautwein ◽  
Mauricio Ferreira
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Biomass Boiler ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced ◽  
Additional Safety

This paper presents and discusses the procedures adopted for repairing and strengthening a damaged reinforced concrete corbel of an industrial biomass boiler. The reinforced concrete corbel was subjected to concrete spalling, favoring the risk of the main tie reinforcement slip in the anchorage zone. The proposed solution involved a local repair with a polymeric mortar and subsequent strengthening using carbon fiber reinforced polymer (FRP) sheets, attending the requirements imposed by the in site conditions and the design plans. The intervention allowed the confinement of the concrete zone subjected to spalling and provided additional safety for the main tie reinforcement of the corbel. The applied technique was demonstrated to be fast, reliable, practical, and cheaper than other available solutions, such as section enlargements with concrete jacketing.

scholarly journals Performance and failure analysis of carbon fiber-reinforced polymer (CFRP) strengthened reinforced concrete (RC) beams

2019 ◽  
Vol 1 (12) ◽  
Author(s):  
Ayesha Siddika ◽  
Krishno Saha ◽  
Md. Sumodro Mahmud ◽  
Sumon Chandra Roy ◽  
Md. Abdullah Al Mamun ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Failure Analysis ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

scholarly journals Bond Properties of Carbon Fiber Reinforced Polymer and Corrosion-Cracked Reinforced Concrete Interface: Experimental Test and Nonlinear Degenerate Interface Law

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5333
Author(s):  
Yongzhi Gong ◽  
Yingjie Shan ◽  
Yuyuan Wu ◽  
Liping Wang ◽  
Xiaojie Liu ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Bond Properties ◽  
Fiber Reinforced ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Concrete Interface ◽  
Nonlinear Degenerate

Existing experimental research on bond properties of the interface between Carbon Fiber Reinforced Polymer (CFRP) and damaged concrete is limited, although CFRP strengthening technology has been widely used for corroded reinforced concrete structures. This work investigated the bond behavior of CFRP to the corrosion-cracked concrete interface, in which three factors were considered for experimentation, including corrosion degree, concrete strength and concrete cover thickness. The tests were conducted by developing a self-balancing double shear lap test device. In addition, a corrosion scene was provided simultaneously to simulate the external corrosion environment. The results showed that three peeling modes of CFRP sheets were observed with respect to corrosion degrees of the steel bars. The effects of the three factors on the stripping bearing capacity and effective bond length of CFRP sheets were discussed by systematic parametric analysis. Finally, a nonlinear degenerate law of CFRP-to-concrete interface considering the corrosion degree was improved and verified in this study.

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