Australian Concrete Strengths

In Australian Standards, concrete strength is determined by the compressive strength of concrete, measured 28 days from pouring. According to AS 1379 (Specification and supply of concrete), concrete strength is tested using compressive cylinder testing, where test cylinders (typically 100 mm x 200 mm or 150 mm x 300 mm) are tested at 7 days and 28 days in a compression testing machine to ensure compliance with the minimum concrete strength grade.

The minimum concrete grade/strength is only one factor that should be considered when determining the type of concrete to use on a project. Other areas, like exposure class, aggregate selection, structural loads, durability requirements, creep, shrinkage, rebar sizes , and long-term deflection, must also be considered. Structural engineers will assess these parameters in accordance with AS 3600 and the National Construction Code when choosing concrete to use.

Australian Concrete Strength Designations

Normal Class Concrete

Normal class concrete in Australia starts with the letter N before the grade and encompasses compressive strengths from 20 to 50 MPa. Normal class concrete is commonly used in residential and light-to-medium commercial construction and is generally readily available from all Australian concrete suppliers.

Grade Compressive Strength Common Applications
N20 20 MPa Residential Applications. Footpaths, kerbs, pathways, and non-structural slabs
N25 25 MPa Residential Applications. Residential – House slabs, footings, patios, and light-duty driveways
N32 32 MPa Residential/Commercial Applications. House slabs, garage slabs, driveways, and suspended slabs
N40 40 MPa Commercial Applications. Structural slabs, industrial floors, and car parks
N50 50 MPa Commercial/Infrastructure Applications. High-rise structural elements and heavy-duty pavements

Table Notes

Special Class Concrete

Special class concrete in Australia is generally designated as concrete with compressive strengths above 50 MPa. Special class concrete is typically specified by structural engineers for specialised applications, including infrastructure projects such as bridges and tunnels, as well as high-rise buildings. These grades of concrete are not generally available off the shelf and instead involve specialised, engineered mix designs.

Grade Compressive Strength Common Applications
S65 65 MPa Infrastructure Applications. Bridges, precast elements, and high-performance structures
S80 80 MPa Infrastructure Applications (High Rise Buildings). Columns, cores, and heavily loaded structural elements
S100 100 MPa Heavy Infrastructure Applications. Bridge girders, high-load precast components, and heavy civil works
S120 120 MPa Specialised Applications. Ultra-High-Performance Concrete for landmark structures, specialised precast, and research/defence applications

Australian Concrete Suppliers

Below is a list of some of the major concrete suppliers in Australia.

Supplier Head Office Locations Serviced
ADBRI (formerly Adelaide Brighton) Adelaide, South Australia Northern Territory, Queensland, New South Wales, Victoria and South Australia
Boral North Ryde, New South Wales Australia wide
Cement Australia Darra, QLD Australia wide
Concrite Sydney, New South Wales New South Wales and Canberra
Duggnas Cradoc, Tasmania Tasmania
Hallet Group Dry Creek, South Australia South Australia
Heidelberg Materials Sydney, New South Wales Australia wide
Holcim Australia North Sydney, New South Wales Australia wide
Hunter ReadyMixed Concrete Thornton, New South Wales New South Wales
HY-TEC CONCRETE Parramatta, New South Wales Queensland, New South Wales, Victoria, Western Australia
Hymix Australia Parramatta, New South Wales Queensland, New South Wales, Victoria, Western Australia
Indpendent Cement Melbourne, Victoria Victoria and New South Wales
Metromix Parramatta, New South Wales New South Wales
NUCON Concrete Upper Coomera, Queensland Queensland and Northern New South Wales
Wagners Toowoomba , Queensland Queensland

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