Compare ready-mix concrete strength grades with Concrete Shopper and understand what to specify before ordering concrete for your Australian project.
Australian normal-class concrete includes standard grades such as N20, N25, N32, N40 and N50. We help customers source ready-mix concrete through our Australia-wide supplier network, but the strength grade should follow the project requirements rather than be selected from a generic application list.
What Do Ready-Mix Concrete Strength Grades Mean in Australia?
Ready-mix concrete grades indicate the characteristic 28-day compressive strength, from N20 at 20 MPa to N50 at 50 MPa. However, strength grade alone is not enough to prepare an order. The required concrete should be confirmed against the project drawings, engineering requirements and relevant specifications.
Concrete Shopper can source ready-mix concrete Australia-wide for projects ranging from DIY work to larger commercial and civil pours.
What Else Needs to Be Specified Besides Concrete Strength?
Choosing from ready-mix concrete strength grades is only one part of ordering. The Cement Concrete & Aggregates Australia guidance on specifying and ordering concrete identifies several parameters that should be specified for normal-class concrete.
These include:
- Strength grade: Confirm the specified N-grade rather than assuming a stronger mix is automatically more suitable.
- Slump: Slump relates to concrete consistency and workability at the point of acceptance and should suit the specification and placement requirements.
- Aggregate size: Normal-class concrete can be ordered with nominated maximum aggregate sizes, depending on the project requirements.
- Placement method: Tell the supplier whether the concrete will be discharged by chute, pumped or placed using another planned method.
- Project assessment: Where required by the specification, confirm whether project assessment is needed.
- Air entrainment: This should also be identified when it forms part of the concrete specification.
Supplying these details reduces the risk of ordering concrete based only on an MPa figure.
Why Should Concrete Grade Follow the Project Specification?
A driveway, footing, slab or commercial floor should not automatically be assigned a particular grade solely because that grade is commonly associated with similar work.
Structural design, exposure conditions, reinforcement and other engineering requirements can change the concrete specification. Higher strength is therefore not a substitute for checking the plans or instructions supplied for the project.
For example, our guide to N25 concrete for residential slabs and footings discusses this commonly requested grade, but the final order still needs to reflect the requirements applying to the individual project.
Other practical details also matter before delivery:
- Concrete volume: Calculate the required cubic metres carefully and allow for the project’s ordering requirements.
- Site access: Confirm whether an agitator can reach the planned discharge location.
- Delivery timing: Coordinate trucks, labour and placement equipment before the first load arrives.
- Pump requirements: If pumping is planned, tell us before ordering so the relevant mix and delivery details can be confirmed.
Order the Concrete Grade Specified for Your Project
Ready-mix concrete strength grades provide a standard way to identify compressive strength, but they should never replace the project specification. Strength, slump, aggregate size, placement and delivery conditions all need to be considered before the order is finalised.
Concrete Shopper helps homeowners, concreters, builders and contractors source concrete through suppliers across Australia. Request a concrete quote with your location, required volume, project type and specified concrete details so we can help source an appropriate supply option.