scholarly journals Near Surface Embedded Application for FRCM Strengthening of RC Beams in Flexure

Author(s):  
HossamEldin El-Sherif ◽  
Usama Ebead
Polymers ◽  
2016 ◽  
Vol 8 (7) ◽  
pp. 261 ◽  
Author(s):  
Kh Darain ◽  
Mohd Jumaat ◽  
Ahmad Shukri ◽  
M. Obaydullah ◽  
Md. Huda ◽  
...  

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.


Author(s):  
Usama Ebead ◽  
Hossameldin El-Sherif

Fibre reinforced cementitious matrix (FRCM) systems are mostly externally bonded (EB) for the strengthening of reinforced concrete (RC) and masonry structures. In this paper, the relatively new concept of near-surface embedded (NSE) FRCM, has been introduced for the flexural strengthening of beams. The process of the application of NSE-FRCM strengthening technique involves the removal of the concrete layer at beam soffit, being the most deteriorated in actual practices. Experimental evidence of the flexural strengthening efficacy of this technique is provided here. Eight RC beams were prepared and tested under four-point loading with the consideration of two test parameters: (a) FRCM material (polyparaphenylene benzobisoxazole (PBO)/carbon/ glass); and (b) the reinforcement ratio (0.5% representing flexure-deficient beams and 1.28% representing typical under-reinforced beams). The strengthening led to gains in ultimate loads that ranged between 31.4% and 84.3%.


2011 ◽  
Vol 94-96 ◽  
pp. 883-886 ◽  
Author(s):  
Chang Zhou Dong ◽  
Jian Zhong Xia

The contrast tests of 1 reinforced concrete(RC) beams and 4 RC beams strengthened with near-surface mounted carbon fiber reinforced polymer (FRP) strips have been carried out, under conditions of different damage degree of RC beams. It is mainly conducted to investigate the effects of FRP strips reinforcement of flexural strength. The experimental results indicate that significant strength on the ultimate load and rigidity of reinforced concrete beams can be realized by mounting FRP strips to the beams, and propagation of cracks were reduced obviously.


2012 ◽  
Vol 256-259 ◽  
pp. 1012-1016
Author(s):  
Gu Sheng Tong ◽  
Yong Xiang Wang ◽  
Qiu Lan Wu ◽  
Yong Sheng Liu

In order to investigate the strengthen effect of different embedment lengths of the NSM strip on different damage levels. A series of tests were conducted on damaged reinforced concrete (RC) beams in flexure strengthened with near surface mounted (NSM) carbon- fiber-reinforced polymer (CFRP) strips, and initial cracking load, ultimate capacity, loading-deflection curves, and failure modes are examined and analyzed in the paper. The results showed that not only the initial cracking loads and ultimate capacities of the beams are significantly increased,but also the flexural stiffness of the beams in the yield and ultimate behavior stages are improved by using NSM-CFRP strips. The strengthen effect on lower damage level RC beams has no obvious difference with that on non-damaged RC beams. Anchoring of the strip end can increase the ultimate load capacities and decrease the ductility of RC beams. Debonding was found to be the primary failure mode in all cases.


2021 ◽  
Vol 30 (3) ◽  
Author(s):  
Komeyl Karimi-Moridani

This study presents a comparison of two methods used for retrofitting Reinforced Concrete (RC) beams, namely, the Externally Bonded Reinforcement (EBR) and the Near-Surface Mounting (NSM) methods. A parametric analysis was carried out using variables such as the retrofitted, the retrofitting method (EBR and NSM), and the thickness of the Carbon Fiber-Reinforced Polymer (CFRP) sheets. To achieve this goal, the finite element method and ABAQUS software were employed. An un-retrofitted beam was also simulated as the control specimen for comparison. Beam responses were compared through load–displacement and energy absorption capacity diagrams. Results show that the higher energy absorption capacity in all CFRP-retrofitted RC beams, which was 1.69–5.54 times higher than in un-retrofitted beams. In the case where half of the beam was reinforced using CFRP sheets, the entire beam assembly and the CFRP sheet contributed to load-bearing, thus delaying crack nucleation in the beam and increasing its energy absorption capacity. As a result, the energy absorption capacity of the beam, in this case, was less than that obtained in the previous one where half the span of the beam was retrofitted.


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