FIBER-REINFORCED
CONCRETE
By Eswin antony
What is fiber-reinforced
concrete?
Fiber-reinforced concrete (FRC) is a composite material
consisting of conventional concrete or mortar reinforced with
discrete fibers. These fibers are typically cut or formed to lengths
up to 2.5 in (64 mm) and can be made from various materials,
including synthetics, steel, natural fibers, or glass. The addition of
fibers improves the concrete's performance in terms of crack
resistance, toughness, and durability under various loading
conditions.
•Fiber reinforced concrete is the composite material
containing fibers in the cement matrix in an orderly manner
or randomly distributed manner. Its properties would
obviously, depends upon the efficient transfer of stress
between matrix and the fibers. The factors are briefly
discussed below:
Fiber-reinforced concrete (FRC) is a type
of concrete that contains fibrous material
to improve structural stability. It is made
up of short discrete fibers that are
uniformly dispersed and orientated
randomly.
The necessity of Fiber
Reinforced Concrete
1.It increases the tensile strength of the concrete.
2.It reduces the air voids and water voids the inherent porosity of gel.
3.It increases the durability of the concrete.
4.Fibers such as graphite and glass have excellent resistance to creep,
while the same is not true for most resins. Therefore, the orientation
and volume of fibres have a significant influence on the creep
performance of rebars/tendons.
5.Reinforced concrete itself is a composite material, where the
reinforcement acts as the strengthening fibre and the concrete as the
matrix. It is therefore imperative that the behavior under thermal
stresses for the two materials be similar so that the differential
deformations of concrete and the reinforcement are minimized.
6.It has been recognized that the addition of small, closely spaced and
uniformly dispersed fibers to concrete would act as crack arrester and
would substantially improve its static and dynamic properties.
Advantages
•Fibers reinforced concrete may be useful where high tensile
strength and reduced cracking are desirable or when
conventional reinforcement cannot be placed
•It improves the impact strength of concrete, limits the crack
growth and leads to a greater strain capacity of the
composite material
•For industrial projects, macro-synthetic fibers are used to
improve concrete’s durability. Made from synthetic
materials, these fibers are long and thick in size and may be
used as a replacement for bar or fabric reinforcement
•Adding fibers to the concrete will improve its freeze-thaw
resistance and help keep the concrete strong and attractive
for extended periods.
•Improve mix cohesion, improving pumpability over long
distances
•Increase resistance to plastic shrinkage during curing
•Minimizes steel reinforcement requirements
Manufacturing Fiber Reinforced
Concrete
The manufacturing process for Fiber Reinforced Concrete is similar to that of conventional concrete, with
the addition of fibers to the mix. The fibers are typically added at a rate of 0.5% to 2.5% by volume of
concrete. The type and length of the fibers used can vary depending on the desired properties of the final
product. Common fiber materials include steel, glass, polypropylene, and nylon.
Applications of Fiber Reinforced Concrete
Fiber Reinforced Concrete has a wide range of applications, including in residential, commercial, and industrial
settings. One of the most common uses of FRC is in the construction of industrial floors. These floors are
subjected to heavy loads, impact damage, and abrasion, and require a high level of durability and strength.
FRC is an ideal material for these applications due to its ability to resist cracking, impact, and wear.
Another common use of FRC is in the construction of precast concrete products, such as pipes, panels,
and beams. These products require high strength and durability to withstand the stresses of
transportation and installation. FRC provides these properties, reducing the risk of damage during
handling and assembly.
1.Fabrication is the main disadvantage
associated with fiber reinforced concrete.
2.It is difficult to pose and handle problems
at the time of placement as the fibres in
concrete make concrete very harsh.
3.Sometimes Fibres may get concentrated
at many places which are not ideal and
thus It results in poor quality concrete.
4. Concrete gets harsh due to fibres so it
may require a higher water/cement ratio.
5.The process of mixing and incorporating
fibers into the cement matrix is costlier and
labor-intensive than the production of
plain cement concrete.
