FIBRE REINFORCED POLYMER
In this paper we are going see about the new technology of reinforcement that is FRP (Fiber reinforced polymers) rebars and its all characteristics. Such as its high strength, lightweight characteristic, creep characteristic, resistant to environmental factor like corrosion effect, fire performance, features and benefits, application, its materials and manufacturing, codes and specification, status and its barriers.
CONCRETE REINFORCEMENT - FRP REBAR
Reinforced concrete is a common building material for the construction of facilities and structures. While concrete has a high compressive strength, it has a very limited tensile strength. To overcome these tensile limitations, reinforcing bars are used in the tension side of concrete structures. Steel rebars have been and are an effective and cost-efficient concrete reinforcement, but are susceptible to oxidation when exposed to chlorides. Examples of such exposure include marine areas, regions where road salts are used for deicing, and locations where salt contaminated aggregates are used in the concrete mixture. When properly protected from ion attack, steel reinforcement can last for decades without exhibiting any visible signs of deterioration. However, it is not always possible to provide this kind of corrosion protection. Insufficient concrete cover, poor design or workmanship, poor concrete mix, and presence of large amounts of aggressive agents all can lead to corrosion of the steel rebar and cracking of the concrete. Fiber reinforced polymer (FRP) composite rebar have the potential to address this corrosion deficiency. FRP rebar can be used as non-prestressed reinforcement in concrete for members subjected to flexure, shear, and compression loadings. FRP Composite rebar are totally resistant to chloride ion attack, offer a tensile strength of 1½ - 2 times that of steel, weigh only 25% of the weight of equivalent size steel rebar, and are highly effective electromagnetic and thermal insulators.
1. Definition of FRP Composites
Not all plastics are composites. In fact, the majority of plastics today are pure plastic, like toys and soda bottles. When additional strength is needed, many types of plastics can be reinforced (usually with reinforcing fibers). This combination of plastic and reinforcement can produce some of the strongest materials for their weight that technology has ever developed...and the most versatile. Therefore, the definition of a fiber-reinforced polymer (FRP) composite is: A combination of
➢ A polymer (plastic) matrix (either a thermoplastic or thermo set resin, such as polyester, is polyester, vinyl ester, epoxy, phenolic) ➢ A reinforcing agent such as glass, carbon, aramid or other reinforcing material
Such that there is a sufficient aspect ratio (length to thickness) to provide a discernable reinforcing function in one or more directions. FRP composite may also contain:
➢ Core materials
That modifies and enhances the final product. The constituent elements in a composite retain their identities (they do not dissolve or merge completely into each other) while acting in concert to provide a host of benefits ideal for structural applications including:
a) High Strength and Stiffness Retention
Composites can be designed to provide a wide range of mechanical properties including tensile, flexural, impact and compressive strengths. And, unlike traditional materials, composites can have their strengths oriented to meet specific design requirements of an application
b) Light Weight/Parts Consolidation
FRP composites deliver more strength per unit of weight than most metals. In fact, FRP composites are generally 1/5th the weight of steel. The composite can also be shaped into one complex part, often times replacing...