Comparative study on flexural behavior of corroded RC beams strengthening using near surface mounted GFRP elements

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.

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Flexural Behavior of RC Beams Strengthened with Near Surface Mounted Prestressed FRP

IABSE Symposium, Weimar 2007: Improving Infrastructure Worldwide ◽

10.2749/weimar.2007.0444 ◽

2007 ◽

Author(s):

Sung-Nam Hong ◽

Jae-Hyun Park ◽

Jong-Sup Park ◽

Jun-Myung Park ◽

Dong-Suk Yang ◽

...

Keyword(s):

Flexural Behavior ◽

Rc Beams ◽

Near Surface ◽

Near Surface Mounted

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COMPARATIVE STUDY ON THEORETICAL MODELS AND DESIGN CODES FOR THE SHEAR CONTRIBUTION OF NSM FRP BARS IN RC BEAMS

Jurnal Teknologi ◽

10.11113/jt.v78.8263 ◽

2016 ◽

Vol 78 (5) ◽

Author(s):

Abdul Aziz Abdul Samad ◽

Noridah Mohamad ◽

Josef Hadipramana ◽

Mohamad Razi Ashaari Amiruddin

Keyword(s):

Comparative Study ◽

Theoretical Models ◽

Design Codes ◽

Rc Beams ◽

Near Surface ◽

Reinforced Polymer ◽

Close Observation ◽

Fibre Reinforced Polymer ◽

Near Surface Mounted ◽

Experimental Findings

This paper presents a comparative study on various theoretical models and design codes for the shear contribution of Near-Surface Mounted (NSM) using Fibre Reinforced Polymer bars to reinforced concrete (RC) beams. Theoretical models from De Lorenzis and A. Nanni, Anwarul Islam and Diaz and Barros, and ACI440.1R-06 and CSA-S806 design codes were selected. All the equations were compared by integrating experimental parameters from Rizzo and De Lorenzis, and Cisneros D. et al. From analysis, it was observed that the theoretical models shows substantial differences by underestimating the experimental findings of Rizzo and De Lorenzis from -68% to -38%. Similarly with Cisneros experimental work, the three theoretical models also produces large differences ranging from -73% to +41%. The analysis from the two design codes from ACI440.1R-06 and CSA-S806 also resulted with both design codes having significant differences ranging from -60% to +48%. However, from close observation, Dias and Barros theoretical model showed more accuracy by having a difference of just -4% with ACI440.1R-06 design code giving a much higher but acceptable difference of +26% compared to CSA-S806 at -60%.

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Reseach on Flexural Behavior of Reinforced Concrete Beams Strengthened with Prestressed Near Surface Mounted CFRP Tendons

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.163-167.3537 ◽

2010 ◽

Vol 163-167 ◽

pp. 3537-3544 ◽

Cited By ~ 1

Author(s):

Ya Hong Ding ◽

Yan Jie Ma

Keyword(s):

Reinforced Concrete ◽

Engineering Application ◽

Reinforced Concrete Beams ◽

Flexural Behavior ◽

Rc Beams ◽

Near Surface ◽

Displacement Ductility ◽

Near Surface Mounted ◽

Strengthening Technique ◽

Strengthening Method

The effectiveness of strengthening reinforced concrete (RC) beams with prestressed near- surface mounted (NSM) carbon fiber reinforced polymer (CFRP) rods has been investigated. The RC beams are tested under monotonic loading. The stressing process, failure capacity, flexural capaticy, displacement ductility and deformation are systematically studied. The text results show that the new strengthening technique with prestressed NSM CFRP rods can enhance the first-crack load, steel-yielding load of beams compared to the control beam. It is worth noting that the prestress can limit the crack width all the way up to failure, reduce the midpoint deflection, and improve the service performance of the strengthened beams. The strengthening method offers an alternative way to existing strengthening method. The results provide a reference for engineering application.

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Flexural Behavior of near Surface Mounted CFRP Bars Strengthened Reinforced Concrete Beams

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.535-537.1702 ◽

2012 ◽

Vol 535-537 ◽

pp. 1702-1710 ◽

Cited By ~ 1

Author(s):

Shuaib H. Ahmad ◽

Abdullah Bin Najm ◽

Antonio Naani

Keyword(s):

Reinforced Concrete ◽

Analytical Model ◽

Concrete Beams ◽

Reinforced Concrete Beams ◽

Flexural Behavior ◽

Rc Beams ◽

Near Surface ◽

Rc Structures ◽

Cfrp Laminates ◽

Near Surface Mounted

In recent decades, use of fibre reinforced polymers (FRP) materials has become very popular for strengthening / re-strengthening of reinforced concrete (RC) structures. This includes flexural and shear strengthening of RC structural members such as slabs, beams and columns.In this study, a computerized analytical model is presented to predict the load-deflection response of flexure critical RC beams externally strengthened with near surface mounted (NSM) CFRP laminates. The analyical model utilizes constitutive material properties of concrete, reinforcing steel, CFRP laminate materials, strain compatibility, sectional analysis to develop moment-curvature relationships, which then are used to generate the load-rotations and load-deflection of the flexure critical RC Beams strengthend with NSM CFRP laminates. For validation of the analytical model, the predictions of the analytical model are compared with the experimental results of flexure critical RC beams strengthened with NSM CFRP laminates and the comparisons are judged to be good.As a part of the experimental investigation of this study, a series of 18 full scale beams Reinforced Concrete Beams strengthened with carbon fiber reinforced polymer (CFRP) laminates will be tested in flexure and shear. The results of flexural tests will be analyzed and compared with the predictions of the analytical model.

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