The use of fibre reinforced polymers (FRP) in strengthening beams in Literature review

The use of fibre reinforced polymers (FRP) in strengthening beams in the u.k - Literature review Example The fibres are usually glass, carbon or Aramid. Fibre reinforcement enhances strength and stiffness. FRP can be categorized in a class of materials known as composite materials, which are made up of two or more materials. When these materials are put together, they retain both their chemical and physical characteristics. FRP differ from other construction materials such as steel or aluminum that are viewed as traditional construction materials (ACI 440.2R-08, 2008). FRP contains properties that are apparent in the direction of applied load while steel or aluminum has uniform properties in all directions. The text will look at FRP and its role in strengthening structures as compared to other construction materials. ... The composite is named after the reinforcing fibre. For instance a composite that is reinforced by carbon, will be referred to as Carbon Fibre Reinforced polymer (CFPR). The three fibres have different properties and carbon is viewed as the most suitable for strengthening. All the three fibres are said to contain a higher stress capacity than ordinary steel. They are also linear elastic. Stiffness and tensile strain are the properties that differ between the fibre types. The three fibres are presented in figure 1. They are compared with an ordinary steel bar and a steel tendon Fig. 1 Properties of different fibres and typical reinforcing steel (ACI Committee 440 (1996) and Dejke (2001). The fibers used in FRP composite material have unique characteristics that make them desirable for strengthening purposes. Some of the characteristics include high levels of elasticity for application in reinforcement, high eventual strength and low disparity of strength among fibers. Other significan t characteristics are enhanced stability to endure manipulation techniques and consistency in diameters and surface dimension in the fibers. Some of the fibers used in FRP composites include glass fibers, carbon fibers and Aramid fibers. Glass fibers These types of fibers find application mainly in the naval and industrial areas to manufacture composites of relatively high performance. They are beneficial due to their high strength. The glass fibers are composed of silicon (SiO2) having a tetrahedral structure (SiO4). The material is further strengthened with aluminum oxides and additional metallic ions. Between the two types of glass fibers, the S-glass fibers normally have an enhanced tensile strength compared to the E-glass. Fiberglass is manufactured through the