Flexural strengthening of RC beams with prestressed NSM CFRP rods – Experimental and analytical investigation

2009 ◽  
Vol 23 (10) ◽  
pp. 3292-3300 ◽  
Author(s):  
Moataz Badawi ◽  
Khaled Soudki
Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2809
Author(s):  
Md. Akter Hosen ◽  
Fadi Althoey ◽  
Mohd Zamin Jumaat ◽  
U. Johnson Alengaram ◽  
N. H. Ramli Sulong

Reinforced concrete (RC) structures necessitate strengthening for various reasons. These include ageing, deterioration of materials due to environmental effects, trivial initial design and construction, deficiency of maintenance, the advancement of design loads, and functional changes. RC structures strengthening with the carbon fiber reinforced polymer (CFRP) has been used extensively during the last few decades due to their advantages over steel reinforcement. This paper introduces an experimental approach for flexural strengthening of RC beams with Externally-Side Bonded Reinforcement (E-SBR) using CFRP fabrics. The experimental program comprises eight full-scale RC beams tested under a four-point flexural test up to failure. The parameters investigated include the main tensile steel reinforcing ratio and the width of CFRP fabrics. The experimental outcomes show that an increase in the tensile reinforcement ratio and width of the CFRP laminates enhanced the first cracking and ultimate load-bearing capacities of the strengthened beams up to 141 and 174%, respectively, compared to the control beam. The strengthened RC beams exhibited superior energy absorption capacity, stiffness, and ductile response. The comparison of the experimental and predicted values shows that these two are in good agreement.


2015 ◽  
Vol 124 ◽  
pp. 163-175 ◽  
Author(s):  
Antonio Bilotta ◽  
Francesca Ceroni ◽  
Emidio Nigro ◽  
Marisa Pecce

Author(s):  
F Ceroni ◽  
A Prota ◽  
G Manfredi ◽  
M Pecce

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
N. Aravind ◽  
Amiya K. Samanta ◽  
Dilip Kr. Singha Roy ◽  
Joseph V. Thanikal

AbstractStrengthening the structural members of old buildings using advanced materials is a contemporary research in the field of repairs and rehabilitation. Many researchers used plain Glass Fiber Reinforced Polymer (GFRP) sheets for strengthening Reinforced Concrete (RC) beams. In this research work, rectangular corrugated GFRP laminates were used for strengthening RC beams to achieve higher flexural strength and load carrying capacity. Type and dimensions of corrugated profile were selected based on preliminary study using ANSYS software. A total of twenty one beams were tested to study the load carrying capacity of control specimens and beams strengthened with plain sheets and corrugated laminates using epoxy resin. This paper presents the experimental and theoretical study on flexural strengthening of Reinforced Concrete (RC) beams using corrugated GFRP laminates and the results are compared. Mathematical models were developed based on the experimental data and then the models were validated.


2018 ◽  
Vol 7 (4) ◽  
pp. 2075 ◽  
Author(s):  
Yasmin Murad

 The use of carbon fiber reinforced polymer (CFRP) sheets is becoming a widely accepted solution for strengthening and repairing rein-forced concrete (RC) structures. To date, the behavior of RC beams, strengthened with 60˚ and 45˚ inclined CFRP sheets, has not clearly explained. An experimental program is proposed in this paper to investigate the flexural behavior of RC beams strengthened with CFRP sheets. CFRP sheets were epoxy bonded to the tension face to enhance the flexural strength of beams inducing different orientation angles of 0˚, 45˚, 60˚ and 90˚ with the beam longitudinal axis. The study shows that strengthening RC beams with CFRP sheets is highly influenced by the orientation angle of the sheets. The orientation angle plays a key role in changing the crack pattern and hence the failure mode. The influence of CFRP sheets was adequate on increasing the flexural strength of RC beams but the ductility of the beams was reduced. The best performance was obtained when strengthening RC beam obliquely using 45˚ inclined CFRP sheets where the specimen experienced additional deflection and strength of 56% and 12% respectively and the reduction in its ductility was the least. It is recom-mended to strengthen RC beams, which are weak in flexure, using 45˚ inclined CFRP sheets.  


2020 ◽  
Vol 323 ◽  
pp. 01010
Author(s):  
Damian Szczech ◽  
Łukasz Krawczyk ◽  
Renata Kotynia

The paper presents test results of reinforced concrete beams flexurally strengthened with Carbon Fibre Reinforced Polymer (CFRP) laminates using the Near Surface Mounted (NSM) technique. RC beams with a cross section of 200 x 400 mm were tested in four-point bending. Two RC beams were strengthened with one NSM CFRP laminate installed into the concrete cover on the bottom side of the beam. One of the beams was strengthened under the self-weight (B10.1) and the second one under initial preloading equal to 83% of the ultimate load of the reference beam (B10.1o). Failure mechanisms, cracking pattern and flexural behaviour of the beams are described in the paper. All the strengthened beams failed by rupture of the CFRP laminates followed by the internal steel reinforcement yielding. High strengthening efficiency of the NSM strengthening was confirmed by 109% and 130% when compared with the non-strengthened beam, respectively for beams B10.1 and B10.1o.


2021 ◽  
Vol 257 ◽  
pp. 113385 ◽  
Author(s):  
Yu Deng ◽  
Zhenzhen Li ◽  
Hexin Zhang ◽  
Alberto Corigliano ◽  
Angus C.C. Lam ◽  
...  

2016 ◽  
Vol 860 ◽  
pp. 156-159
Author(s):  
Seyha Yinh ◽  
Qudeer Hussain ◽  
Winyu Rattanapitikon ◽  
Amorn Pimanmas

This experimental study has been conducted on the efficiency of epoxy-bonded hemp fiber reinforced polymer (FRP) composites in flexural strengthening of reinforced concrete (RC) beams. A total of five RC beams were cast and tested up to failure. The test parameters included fiber thickness and strengthening configuration. The experimental results show the capability of hemp FRP composites to increase the loading capacity in flexure of RC beams compared with the un-strengthened beam. The enhancement of ultimate load becomes more significant as the fiber thickness is increased. The effectiveness of strengthened beams in U-wrapped scheme is found greater than strengthened beams in bottom-only scheme. Based on results, it indicates that hemp FRP has a potential to considerably increase the strength and stiffness of the original RC beam.


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