WHAT IS STEEL REINFORCMENT?
May 21st 2019
Whether you’re building a driveway concrete slab or engineering a 40 level office building, reinforcement steel is an essential element of the concrete foundations to provide the tensile and compressive strength required.
Reinforcing steel, (Usually called rebar and mesh) is made from a raw material called iron ore. It is used in concrete to provide additional strength, as concrete is weak in tension and steel is strong in tension and compression. This makes steel and concrete like a gin and tonic; they are incredibly effective together if you know what I mean!
Here are the common steel products sold by Australian steel reinforcement suppliers:
It turns out steel and concrete have similar coefficients of thermal expansion, which means as the temperature changes (during day and night, season to season) that the structure experiences minimum stress in any structural elements; like beams, columns and slabs.
What is reinforcing steel made of?
Reinforcing steel typically consists of carbon steel, which is hot rolled with deformation patterns (The ribbed profiles you see on the rebar and wire), allowing for a stronger bond to the concrete.
The steel bars and mesh are produced from iron ore and recycled steel in different steel mills around the world. While iron ore is an excellent material, using recycling steel is more energy efficient and has other benefits like reduced pollution and exhaustion of natural resources.
The Australian standards, sizes and grades?
Reinforcement that is used in concrete elements requires two primary Australian standards:
- AS3600-2009 (Concrete Structures) and,
- AS/NZS4671-2001 (Steel Reinforcing for Concrete).
There are also other standards that apply to testing, welding and galvanising.
Understanding the codes of Reinforcement Bar and Wire
Understanding the reinforcing steel codes can be confusing, as companies use different coding for their products. So, we have broken it down using the Australian standard codes, which we use today.
You may have seen the code ‘D500N12’, but as per industry standard it’s generally known by its abbreviated term ‘N12’.
Here is D500N12 broken down:
D = Deformed Rebar
500 = Yield Strength (MPa)
N = Normal Ductility
12 = Diameter (mm)
Just remember, if the code starts with N i.e ‘N16’ the N represents (Deformed bar). ‘R’ (Round bar), ‘RW’ (Ribbed wire) or ‘W’ (Round wire).
Use the codes below to understand each product and its specifications.