Over many years, many research work performed to render
concrete with flexural and tensile strength with its natural high compressive
strength. The result is reinforced concrete having both longitudinal steel to
provide bending and torsional strength and transverse steel (stirrups) to
provide shear and torsional strength in flexural members. In case of
compression member with longitudinal and transverse steel (tie or spiral) are
used to provide compression plus bending strength. now-a-days short length
steel wire or thin steel sheet are used to increase flexural strength, crack
resistance and explosion resistance.
This special reinforcement is called steel fiber and the
resulting concrete is steel fiber reinforced concrete. This type of concrete is
widely used in abrasion suspected wearing surface.
The standard size and shape of steel fibers and their
amount to be added in concrete mass are listed in the table below:
Fiber shape
|
Length, mm
|
Width, mm
|
Dia, mm
|
Thickness, mm
|
Steel wire having low carbon content
|
10 – 60
|
---
|
0.25-0.75
|
---
|
Steel flat sheet
|
10 – 60
|
0.25-0.90
|
---
|
0.15-0.40
|
This is to note that increase of strength properties is
dependent on shape of fiber, quantity of fiber in the concrete mass and the
type of fiber materials. How fiber are mixed in concrete mix is discussed in
the post “HOW ARE STEEL FIBER USED IN CONCRETE?”
