This document presents information on fiber reinforced concrete (FRC). It discusses that FRC adds fibers to concrete to control cracking from shrinkage and improve tensile strength. Common fiber types include steel, glass, and polymers. FRC has applications in thin sheets, pipes, precast elements, and floors where it improves durability and reduces cracking. The properties of FRC depend on fiber volume, aspect ratio, orientation, and the fiber-matrix bond. FRC provides benefits like increased strength, ductility, impact resistance, and reduced crack widths compared to plain concrete. However, it can reduce workability, especially with higher fiber volumes or aspect ratios.

1. DR B R AMBEDKAR
NATIONAL INSTITUTE OF TECHNOLOGY
DEPARTMENT OF CIVIL ENGINEERING
PRESENTATION ON : FIBER REINFORCED CONCRETE
SUBMITTED TO: SUBMITTED BY
:
DR KANISHK KAPOOR BHANVAR CHAND MEENA

2. Contents
• Introduction
• why use fibers ?
• Application of FRC material
• Material use
• Factor Affecting the Properties of FRC
• Comparation between PCC and FRC
• Advantage and Disadvantage of FRC
• Conclusion

3. INTRODUCTION
• Concrete is strong in compression but weak in tension. As concrete is
brittle material the failure in concrete due to tension is sudden. There
are also cracks in concrete due to shrinkage and these micro cracks
propagate and leads to failure.
• To safeguard the concrete against flexural cracks fibres are used in
concrete section which is known as fibre reinforced concrete.

4. Why use fiber ?
• Fibers are used in concrete to control cracking due to plastic shrinkage
and to drying shrinkage. They also reduce the permeability of concrete
and thus reduce bleeding of water.
• Cracks in reinforced concrete members extended freely until
encountering a rebar.
• Fiber reinforced concrete is used when there is requirement for
elimination small cracks.

5. Applications of FRC materials
• Thin sheets
• Roof tiles
• Pipes
• Prefabricated shapes
• Panels
• Slabs on grade
• Precast elements
• Impact resisting structures

6. Fiber- reinforced concrete (FRC)
Fiber- reinforced concrete (FRC) is concrete containing fibrous material
which increases its structural integrity. It contains short discrete fibres
that are uniformly distributed and randomly oriented. Fibres include
steel fibres, glass fibres, synthetic fibres and natural fibres – each of
which lend varying properties to the concrete. In addition, the character
of fibre-reinforced concrete changes with varying concretes, fibre
materials, geometries, distribution, orientation, and densities.

7. Types of fiber used in FRC
• Steel Fiber Reinforced Concrete
• Polypropylene Fiber Reinforced (PFR) concrete
• Glass-Fiber Reinforced Concrete
• Asbestos fibers
• Carbon fibers and Other Natural fibers

8. Steel Fiber Reinforced Concrete
• Diameter Varying from 0.3-0.5 mm. (IS:280-1976)
• Length varying from 35-60 mm.
• Various shapes of steel fibers.

10. Material Used
• Cement
• water
• Coarse aggregates
• Fine aggregates
• Steel fibres

11. Factors affecting the Properties of FRC
• Volume of fibers
• Aspect ratio of fiber
• Orientation of fiber
• Relative fiber matrix stiffness

12. Volume of fiber
• Low volume fraction (less than 1%)
Used in slab and pavement that have large exposed surface leading
to high shrinkage cracking
• Moderate volume fraction(between 1 and 2 percent)
Used in Construction method such as Shortcrete & in structures
which requires improved capacity against delamination, spalling &
fatigue.
• High volume fraction(greater than 2%)
Used in making high performance fiber reinforced composites.

14. Aspect Ratio of fiber
• It is defined as ratio of length of fiber to it’s diameter (L/d).
• Increase in the aspect ratio upto 75,there is increase in relative strength
and toughness.
• Beyond 75 of aspect ratio there is decrease in relative strength and
toughness.

15. Orientation of fibers
• Aligned in the direction of load
• Aligned in the direction perpendicular to load
• Randomly distribution of fibers

16. Relative fiber matrix
• Modulus of elasticity of matrix must be less than of fibers for efficient
stress transfer.
• Low modulus of fibers imparts more energy absorption while high
modulus fibers imparts strength and stiffness.
• Low modulus fibers e.g. Nylons and Polypropylene fibers
• High modulus fibers e.g. Steel, Glass, and Carbon fibers

17. Comparison
between Plain Concrete and Fiber
Reinforced Concrete

18. Advantage of Steel fiber
• High structural strength
• Reduced crack widths and control the crack widths tightly, thus
improving durability.
• Less steel reinforcement required.
• Improve ductility
• Reduced crack widths and control the crack widths tightly, thus
improving durability.
• Improve impact– and abrasion–resistance

19. Disadvantage of FRC
• Reduces the workability.
• Loss of workability is proportional to volume concentration of fibers
in concrete.
• Higher Aspect Ratio also reduced workability.

20. Conclusion
• The total energy absorbed in fiber as measured by the area under the
load-deflection curve is at least 10 to 40 times higher for
fiberreinforced concrete than that of plain concrete.
• Addition of fiber to conventionally reinforced beams increased the
fatigue life and decreased the crack width under fatigue loading.
• At elevated temperature SFRC have more strength both in
compression and tension.
• Cost savings of 10% - 30% over conventional concrete flooring
systems.

21. THANK YOU