Evaluation of externally bonded CFRP systems for the strengthening of RC slabs
The use of carbon fiber-reinforced polymer (CFRP) as externally bonded reinforcement (EBR) for the repair and strengthening of deficient structures have been taking place since the late 1980’s. Continuous efforts in material development and research activities, with strong links to engineering practice, give this application more and more interest worldwide. This paper presents an experimental study on flexural strengthening of reinforced concrete (RC) slabs with different CFRP systems, using different EBR techniques. All the slabs were tested to failure under simply supported conditions. CFRP EBR increased the flexural strength and reduced the deflections and crack widths of the strengthened slabs. Two modes of failure were observed, delamination and rupture of the CFRP reinforcement.
Use of Carbon Fiber Reinforced Polymer Laminate for strengthening reinforced concrete beams in shear : A review
The use of Fiber Reinforced Polymer (FRP) is becoming a widely accepted solution for repairing and strengthening ageing in the field of civil engineering around the world. Several researches have been carried out on reinforced concrete beams strengthened with fiber reinforced polymer composite. Some of the works were focused on shear strengthening compared with flexural strengthening that had the largest share. This paper reviews 10 articles on carbon fiber reinforced polymer strengthened reinforced concrete beams. Finally, this paper attempts to address an important practical issue that is encountered in shear strengthening of beams with carbon fibre reinforced polymer laminate. This paper also proposes a simple method of applying fibre reinforced polymer for strengthening the beam with carbon fibre reinforced polymer. Keywordcarbon fibre reinforced polymer, concrete beams, flexural strengthening, shear strengthening
Myriad Convention Center Floor System Reinforcement
It was determined that additional flexural strength, ductility and crack-control and shear strength were needed in the Myriad convention center unbonded post-tensioned street-level floor system. Fiber reinforced polymer (FRP) reinforcement was designed to correct the insufficiencies. The challenge in the project, aside from the mechanics unique to FRP reinforcement, was to present the design in such a way as to allow and encourage as many bidders as possible to bid on the construction. In particular, since there are no standardized properties for any given type of FRP, the possibility that not all bids would involve the same properties had to be accommodated--especially in the flexural design. Generally, for each strengthening location, two flexural designs were completed: one giving required FRP force level at minimum ultimate FRP strain and one required FRP force level on concrete crushing at the limit state of failure, the latter associated FRP ultimate strain termed "High Threshold" ultimate strain. Required force level for any ultimate strain could then be obtained by linear interpolation. Ability to use FRP for shear reinforcement was limited due to low available beam stem development length. Both glass, with restrictions, and carbon FRP were allowed for shear reinforcement.