NEAR SURFACE MOUNTED BAMBOO REINFORCEMENT FOR FLEXURAL STRENGTHENING OF REINFORCED CONCRETE BEAMS

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Yanuar Haryanto ◽  
Buntara Sthenly Gan ◽  
Arnie Widyaningrum ◽  
Agus Maryoto
Keyword(s):  
Reinforced Concrete ◽  
Experimental Tests ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Element Analysis ◽  
Near Surface ◽  
Flexural Strengthening ◽  
Near Surface Mounted ◽  
Nsm Technique

Near Surface Mounted (NSM) is a technique performed for the installation of strengthening material into grooves cut into the concrete cover of reinforced concrete (RC) beams bonded using a bonding agent. This technique is becoming more widely recognized because of its efficiency, effectiveness, and ease of application. We investigated flexural strengthening of RC beams with the NSM technique using bamboo reinforcements, through both experimental tests and a finite element analysis (FEA). The experimental tests were carried out on three RC beams, one consisting of a control beam, and the other two strengthened by the NSM technique with two steel reinforcements, and four bamboo reinforcements. From the experimental tests, we found that the flexural strength of the beam with NSM bamboo reinforcements was increased by 41.7% and the deflection ductility index was reduced by 21.55%. The mode of failure observed in all the strengthened beams was a flexural failure. Finally, the result of FEA behaved similarly to the results of the experimental test.

scholarly journals Flexural strengthening of RC beams with NSM CFRP laminates

2020 ◽  
Vol 323 ◽  
pp. 01010
Author(s):  
Damian Szczech ◽  
Łukasz Krawczyk ◽  
Renata Kotynia
Keyword(s):  
Reference Beam ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Near Surface ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Carbon Fibre Reinforced Polymer ◽  
Bottom Side ◽  
Cracking Pattern

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.

Study on Flexural Performance of Damage RC Beams Strengthened with near Surface Mounted FRP Strips

2011 ◽  
Vol 94-96 ◽  
pp. 883-886 ◽  
Author(s):  
Chang Zhou Dong ◽  
Jian Zhong Xia
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Near Surface ◽  
Flexural Performance ◽  
Damage Degree ◽  
Reinforced Polymer ◽  
Significant Strength ◽  
Near Surface Mounted ◽  
Frp Strips

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.

Calculation of Shear Capacity of Steel Reinforced Concrete Beams Strengthened with Near-Surface Mounted CFRP Rods

2012 ◽  
Vol 193-194 ◽  
pp. 852-854
Author(s):  
Wei Hua Chen ◽  
Mei Qin Wu
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Beam ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Near Surface ◽  
Steel Reinforced Concrete ◽  
Carbon Fiber Reinforce Polymer ◽  
Near Surface Mounted ◽  
Fiber Reinforce

Some calculated methods of shear capacity of RC beams strengthened with NSM(near-surface mounted) CFRP(Carbon fiber reinforce polymer) rods are reviewed based on the experimental data on shear capacity of RC beams strengthened with NSM CFRP rods. Therefore, according to the destruction forms of steel reinforced concrete beam strengthened with NSM CFRP rods, the formula for calculating the shear capacity of the beam is given. The formula is expressed clearly, simple and easy to use.

scholarly journals Assessment of RC elements strengthened with NSM FRP rods by experimental tests

2020 ◽  
Vol 323 ◽  
pp. 01008
Author(s):  
Roberto Capozucca ◽  
Erica Magagnini
Keyword(s):  
Experimental Tests ◽  
Concrete Cover ◽  
Beam Model ◽  
Rc Beams ◽  
Near Surface ◽  
Beam Elements ◽  
Damage Degree ◽  
Reinforced Polymer ◽  
Near Surface Mounted ◽  
Vibration Tests

Near surface mounted (NSM) technique of strengthening with FRP rods inserted in grooves on the concrete cover of damaged RC beams has been improved in recent years. The aim of this paper is the examination of the static and dynamic behaviour of undamaged and damaged reinforced concrete (RC) beams with free-free ends. RC beams strengthened with NSM Glass and Carbon fiber reinforced polymer (G-CFRP) rods have been experimentally analysed. The damage of the RC beam model was obtained by the cracking of concrete under bending tests. The detection of damage and monitoring of RC beams with and without strengthening were carried out by vibration tests assuming free-free ends at different degree of damage. Envelope diagrams of Frequency Response Functions (FRFs) obtained by the dynamic experimental tests are shown and the changes of natural frequency values are correlated to the damage degree of beam elements. Experimental results are discussed with particular emphasis on the aspect of the loss of bond.

Concrete cover separation of reinforced concrete beams strengthened with near-surface mounted method: Mechanics based design approach

2019 ◽  
Vol 22 (7) ◽  
pp. 1739-1754
Author(s):  
Ahmad Azim Shukri ◽  
Zainah Ibrahim ◽  
Huzaifa Hashim
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fibre ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Near Surface ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Near Surface Mounted ◽  
Concrete Cover Separation

The primary mode of premature failure for near-surface mounted strengthened beams is the concrete cover separation. Due to its complexity, most of the prediction methods for concrete cover separation tend to be empirical based, which can limit their usage to specific near-surface mounted strengthening configurations. In response to that, this article presents a mechanics-based design which uses the moment-rotation approach and the global energy balance approach which is less reliant on empirical formulations, as the mechanics of reinforced concrete beam such as tension stiffening and propagation of concrete cover separation debonding crack are directly simulated rather than empirically derived. The proposed design procedure was validated against published experimental results of reinforced concrete beams strengthened with near-surface mounted carbon fibre–reinforced polymer bars, near-surface mounted carbon fibre–reinforced polymer strips or side-near-surface mounted carbon fibre–reinforced polymer bars and show good accuracy. As it is less reliant on empirical formulations, the proposed design procedure should be applicable to various near-surface mounted reinforcement configurations and materials.

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