Fiber Reinforced Concrete can be defined as a composite material consisting of mixtures of cement , mortar or concrete and discontinuous , discrete , uniformly dispersed suitable fibers. Fiber reinforced concrete are of different types and properties with many advantages. Continuous meshes , woven fabrics and long wires or rods are not considered to be discrete fibers.
Fiber is a small piece of reinforcing material possessing certain characteristics properties. They can be circular or flat. The fiber is often described by a convenient parameter called “aspect ratio”. The aspect ratio of the fiber is the ratio of its length to its diameter. Typical aspect ratio ranges from 30 to 150.
Fiber reinforced concrete (FRC) is concrete containing fibrous material which increases its structural integrity. It contains short discrete fibers that are uniformly distributed and randomly oriented. Fibers include steel fibers , glass fibers , synthetic fibers and natural fibers. Within these different fibers that character of fiber reinforced concrete changes with varying concretes , fiber materials , geometries , distribution , orientation and densities.
Fiber-reinforcement is mainly used in shotcrete , but can also be used in normal concrete. Fiber-reinforced normal concrete is mostly used for on-ground floors and pavements , but can be considered for a wide range of construction parts (beams , pliers , foundations etc.) either alone or with handtied rebar.
Concrete reinforced with fibers (which are usually steel , glass or “plastic” fibers) is less expensive than handtied rebar , while still increasing the tensile strength many times. Shape , dimension and length of fiber is important. A thin and short fiber , for example short hair-shaped glass fiber, will only be effective the first hours after pouring the concrete (reduces cracking while the concrete is stiffening) but will not increase the concrete tensile strength.