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Have you ever used NSM -CFRP in your site what's your opinion?

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Question added by SAMIH ABBAS KOTTACKAL , STRUCTURAL ENGINEER TRAINEE , CASE STRUCTURAL ENGINEERS
Date Posted: 2014/10/25
Myra Ansus
by Myra Ansus , quantity surveyor engineer , Proscape LLC

Yes, I have professional experienced using NSM-CFRP. We used that product at Beams of Bridges and Buildings. It's provides additional strength to the structure to carry loads. We call this kind of works in the philippines as retrofitting.

Deleted user
by Deleted user

copy from my graduation project (if you want the book of the project email me at ):

 

Abstract

Existing reinforced concrete (RC) structure can be strengthened upon the addition of externally bonded high-strength light-weight fiber-reinforced polymer (FRP) composites. An abundance of research over the last two decades has established the effectiveness of the externally bonded FRP via extensive experimental testing.

Perhaps the most commonly occurring failure mode though is premature debonding of the FRP and debonding generally occurs at strains well below the strain capacity of the FRP. Debonding failures are undesirable as they are typically brittle and represent an underutilization of the FRP material. A straight forward means to prevent or at least delay debonding is by the addition of mechanical anchors, however, research to date on anchors is extremely limited. Of the various anchor concepts examined to date by researchers, this dissertation will focus on anchors made from steel which are herein referred to as steel anchors.

In this research we studied strengthening of RC slabs with fiber reinforced polymer (FRB) and using steel anchors to get the maximum strain without happening of debonding.

Fourteen reinforced concrete test specimens were constructed. Two of them were tested as a quality control and the other twelve specimens were strengthened with different types of FRP (glass and fiber). Eight of the last group we used steel anchors.

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Conclusion

6.1 Introduction

this research was about strengthening concrete slabs to make it carry more live load using fibers (carbon fiber ,glass fiber ) and to study the difference in strength of slabs externally reinforced by different types of fiber. And usage of anchor to fix the fiber. And studying the increase in strength of slabs externally reinforced by fiber.

we casted 14 concrete slabs with dimension 350 cm length 12 cm height 85 cm wide and it has a compressive strength of 450 kg\\cm2.

And it was reinforced as explained in chapter 4.

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6.2 Conclusion

 The first two slabs were loaded without fiber as control slabs. The two slabs reached the yield at (5.6 ton, 5.9 ton), and absorbed (11629.17 kg.cm, 12853.68 kg.cm).

 The third slab were externally reinforced with carbon sheet 150 cm long, 20 cm wide. It reached its yield at 6.2 ton. and absorbed 200686.6 kg.cm

 The fourth slab were externally reinforced by 2 carbon laminates 110 cm long, 10 cm wide. It reached its yield at 5.1ton. and absorbed 13606.72 kg.cm

 The fifth slab were externally reinforced by glass sheet 110 cm long, 20 cm wide. It reached its yield at 6.2 ton. and absorbed 120894.9 kg.cm

 the sixth slab were externally reinforced by glass sheet 110 cm long, 20 cm wide and it was anchored by 4 steel anchors. It reached its yield at 5.9 ton. and absorbed 12167.16 kg.cm

 the seventh slab were externally reinforced by carbon sheet 110 cm long, 20 cm wide and it was anchored by 4 steel anchors it reached its yield at 6.6 ton. and absorbed 173466.5 kg.cm

 the eighth slab were externally reinforced by 2 carbon laminate 80cm long, 10 cm wide and it was anchored by 4 steel anchors. It reached its yield at 5.2 ton. and absorbed 144064.6 kg.cm

 the ninth slab were externally reinforced by glass sheet 110 cm long 20 cm wide and it was fixed at its end by 2 carbon rib 50cm wide, 10cm long, and the rib sheet were anchored by 4 steel anchors. It reached its yield at 5.4 ton. and absorbed 109323.4 kg.cm

 the tenth slab were externally reinforced by 2 carbon laminates 110cm long, 10 cm wide and it was anchored by 4 steel anchors. It reached its yield at 6.2 ton. and absorbed 161687 kg.cm

 The eleventh slab were externally reinforced by glass sheet 110 cm long, 20 cm wide and it was anchored by 4 steel anchors. It reached its yield at 5.9 ton. and absorbed 125781.4 kg.cm

 the twelfth slab were externally reinforced by glass sheet 110 cm long, 20 cm wide and it was fixed at its end by 2 carbon rib 50cm wide, 10 cm long. 6.9 ton. and absorbed 9942.55 kg.cm

 The thirteenth slab were externally reinforced by carbon sheet 110cm long, 20 cm wide and it was anchored by 4 steel anchors. It reached its yield at 6.6 ton. and absorbed 15108.8 kg.cm

 the fourteenth slab were externally reinforced by carbon sheet 110cm long, 20 cm wide and it was fixed at its end by 2 carbon rib 50cm wide, 10cm long, and the rib sheet were anchored by 4 steel anchors. It reached its yield at 5.3 ton. and absorbed 12841.6 kg.cm

 The slab with the highest strength was the twelfth slab it reached its yield at 6.9 ton.

 The slab with lowest strength was the fourth slab it yielded at 5.1 ton.

 The slab with the highest energy absorbed is the third slab it absorbed 200686.6 kg.cm

 The slab with the lowest energy absorbed is the twelfth slab it absorbed 9942.55 kg.cm

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6.3 Observation and comments

 Carbon sheets gives more strength than the glass sheet.

 Anchors gives more strength it shown in loads that anchored slabs can endure more load (about 1 ton).

 Carbon laminates makes the slab absorb more energy.

 Anchors best usage are with laminates.

 Carbon rib gives the highest strength but it lowers the energy absorption.

 Using carbon rib with steel anchor lowers the strength of slab than using carbon ribs without anchors.

 Using anchors with carbon and glass sheet lower the energy absorbing.

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