Strengthening of R.C Beams using Fiber Reinforced Polymers

Abstract

R.C structures have a certain age after which they are not safe to use. They deteriorate over time and become unsuitable for the purpose they were built for. R.C structures could be in the form of beams, columns, footings, slabs, girders, pylons etc but the scope of this project is limited to beams only. R.C beams could either be replaced or they can be repaired using different retrofitting techniques. Retrofitting techniques are of various kinds that are used in industry with both advantages as well as drawbacks. Retrofitting techniques are more suitable, especially for a country like Pakistan, where weak economy and high inflation rate are prevalent. Retrofitting techniques are only used when the structure has not been completely damaged. Instead of replacing damaged structures, effective techniques of repairing can result in time saving and minimal cost. Fiber Reinforced polymers (FRP) is relatively new class of composite materials which has proven itself efficient and economical for the development and repair of new and deteriorated structures in construction industry. Because of its high strength to weight ratio, FRP’s and have been widely used in developed countries for retrofitting and other maintenance operations. Though in Pakistan, this technology needs to be highlighted. Most of the engineers and consultancy firms are reluctant to use this technology probably because they have enough confidence in classical methods. The objective of this project is to present a cheaper solution of retrofitting/repair damaged beams. One possible option is to repair the damaged sections using Fiber Reinforced Polymers. Fibers in a polymer matrix make up FRP’s. Fibers can be glass, carbon, aramid etc. This project demonstrates the application of carbon Fiber Reinforced Polymers on R.C beams. Two different types of CFRPs were used. The response was found from experimental program and design calculations. Study results from experimental program were compared with design calculations. Recommendations were made on the basis of comparison of results.