Main Roads Concrete Specifications: Why Requirements Differ Across Australia
October Technical Insights
Why the same strength grade does not mean the same mix requirements
A concrete mix that performs well on one road project should not automatically be carried across to another. Even when both projects specify 40 MPa, the requirements for cementitious materials, water–cementitious ratio, aggregate suitability, durability testing and mix acceptance can differ.
For concrete producers and contractors, these differences affect more than compliance. They influence material selection, trial programmes, production controls, approval timeframes and the cost of supply.
At Concrete & Geotechnical Engineering, our recommendation is to review the complete project specification before selecting or pricing a mix. Start with the application and the nominated contract documents, then work through the technical and production requirements.
There is no single Australian Main Roads concrete specification
“Main Roads concrete” is a convenient industry description, but Australia does not have one national specification covering every road authority and application.
Queensland uses Transport and Main Roads specifications. New South Wales uses Transport for NSW documents. Victoria uses the Department of Transport and Planning framework, including documents still commonly identified by their VicRoads titles. Western Australia uses Main Roads WA specifications, South Australia uses DIT Master Specifications, and Tasmania publishes its own standard sections and approval arrangements.
Some requirements increasingly draw on Austroads Technical Specifications. However, a locally modified adoption must be read with its amendments and contract requirements. A shared reference does not establish identical acceptance criteria.
Queensland
Select the document for the concrete application
MRTS70 Concrete covers road and bridge structures and distinguishes normal-class and special-class concrete. Concrete pavement subbase and base are addressed separately through MRTS39 and MRTS40. Shotcrete and fibre-reinforced concrete also have dedicated specifications that refer back to MRTS70.
The MRTS70 framework includes registered products and suppliers, mix design submissions, material conformance and approval hold points. Its requirements also address trials for long-distance transport or extended placement.
For producers, the first question should therefore be: which specification applies to this element? A bridge mix submission should not be assumed to satisfy pavement, piling or fibre-concrete requirements simply because its strength is adequate.
New South Wales
Match the specification to the concrete application
TfNSW’s framework includes TS 00146 Supply of Special Class Concrete, a modified adoption of Austroads ATS 5315-23. Bridgeworks documents, including B80, reference this concrete supply specification.
This makes the relationship between documents important. Reviewing the bridge specification alone may leave material and testing requirements overlooked. The nominated editions, annexures and applicable amendments need to be identified together.
TS 00146 also requires aggregate sources and designations to be included in mix documentation, with supporting compliance evidence where the source is not approved through the relevant registration or prequalification scheme.
Before using an existing mix, check its materials and supporting evidence against the project’s actual document set.
For concrete pavements, the applicable TfNSW specifications also include:
· R83 – Concrete Pavement Base
· R84 – Concrete Pavement Subbase
· R82 – Lean Mix Concrete Subbase
These pavement specifications should be reviewed separately from structural concrete requirements, using the editions and amendments nominated in the contract.
Victoria
Understand the grade designation and durability framework
Section 610 Structural Concrete is an important reference within the Victorian specification framework. Its VR grade designations combine minimum cementitious content with specified strength: the number preceding the slash is not another strength value.
The Section 610 framework also addresses durability through requirements such as volume of permeable voids, commonly called VPV, alongside strength, mix design and production controls.
For suppliers, the practical point is to read the complete grade designation and the contract’s nominated edition. A strength-only comparison between a VR mix and a standard commercial mix can miss significant requirements.
Project amendments and associated bridge technical notes must also be checked. An older Section 610 copy from a previous job should not be treated as the controlling document for a new contract.
Western Australia
Explicit mix limits and trial requirements matter
Main Roads WA Specification 820 Concrete for Structures sets out concrete classes with target strengths, maximum water–cement ratios and minimum cementitious contents.
For example, Table 820.2 in the edition issued 29 August 2025 lists S40 with a target strength of 48 MPa, a maximum water–cement ratio of 0.45 and minimum cementitious content of 380 kg/m³. These are requirements of that specification table, not national limits for every 40 MPa mix.
The specification also addresses combined aggregate grading, trials, VPV and drying shrinkage. Clause 820.13 specifies a maximum of 600 microstrain after 56 days of drying, with a separate 700-microstrain limit for self-compacting concrete used in piling.
Review the project’s nominated specification and amendments before applying these values. Meeting compressive strength alone does not demonstrate compliance with the full mix requirements.
South Australia
Supply, placement and durability requirements are linked
DIT separates concrete supply and placement through documents including ST-SC-S7 Supply of Concrete and ST-SC-C7 Placement of Concrete.
The October 2025 version of ST-SC-S7 covers special-class concrete and normal-class concrete above 32 MPa. N20, N25 and N32 are directed to the separate normal-class specification.
Its submission requirements include material proportions, aggregate information, moisture controls, water–cementitious ratio, admixtures and performance evidence. High-durability requirements apply to exposure classification B2 and more severe conditions, including VPV testing.
Shrinkage acceptance is linked to the design documents. Consequently, the drawings and project requirements must be reviewed alongside the supply specification rather than assuming one universal shrinkage limit.
Tasmania
Similar documents still require a local approval pathway
Tasmania publishes Section 610 Structural Concrete within its bridgeworks standard sections and uses the Victorian VicRoads quarry accreditation process for relevant material sources.
Its published registration guidance identifies concrete mix applications as contract-specific and directs submissions to the Superintendent administering the works contract.
This is a useful example of why familiar specification numbering does not remove the need for a local review. Check the Tasmanian contract edition, source accreditation, supporting test evidence and submission pathway before offering a mix.
What about the territories
The Northern Territory publishes separate roadworks and bridgeworks specifications. The ACT uses Municipal Infrastructure Technical Specifications, including MITS 10 Concrete for General Works and related documents for kerbs, paths and other applications.
Treat each as its own document framework. Confirm which specification applies to the particular asset rather than assuming a neighbouring state’s approval is sufficient.
The differences that deserve attention before quoting
The following review is our recommended starting point for a new road authority project.
Requirement | What to establish before pricing |
Application and documents | Structural concrete, pavement, piling, precast or general works; nominated editions and amendments |
Cementitious system | Minimum content, permitted cement types, SCM proportions and material approval requirements |
Water and workability | Maximum water–cementitious ratio, slump or spread, retention needs and adjustment procedures |
Aggregates | Source suitability, grading, absorption, reactivity and evidence required for acceptance |
Performance testing | Strength ages, shrinkage drying period, VPV and any application-specific tests |
Supply and acceptance | Trials, submission lead times, hold points, production testing, transport and curing requirements |
Pay particular attention to how a requirement is expressed. Minimum GP cement and minimum total cementitious content are different quantities. Likewise, “56 days of drying” is different from “56 days after casting”.
A numerical limit only becomes useful when the test method, specimen preparation, assessment age and acceptance rule are understood.
Price the concrete requirement as a complete scope
Our commercial recommendation is to assess the full cost of meeting the specification, including trials, testing, documentation, material changes and production support.
For illustration, an unallowed cost of $4/m³ across 5,000 m³ is $20,000 before additional investigation or rework. This is a simple pricing example, not an estimate of typical project costs.
A specification review also helps identify where clarification is needed and whether a proposed alternative requires formal acceptance. Keep optimisation within the approved project requirements.
Start with the specification and your actual materials
A good project mix connects the nominated requirements with the available materials, plant capability, delivery conditions and placement method.
CGE supports producers and contractors with specification reviews, project-specific mix development, materials assessment, trial planning and technical submissions.
If you are tendering for a road or infrastructure project, send us the specification and your current material information. We can help identify what needs to be demonstrated and develop a practical path from mix design to production.
Independent Technical Advice. Practical Solutions. Better Concrete.
Reference notes
Prepared for October 2026. This article is a practical overview, not a substitute for the contract specification. Numerical examples relate to the identified document edition. Confirm the nominated edition, project amendments and approval requirements for each job.
· Section 610 framework example hosted by Wyndham City Council — council version dated November 2021, based on VicRoads February 2020; used to explain the framework, not establish the current statewide contractual edition.
Comments