Test Methods and Specifications
Lean-mix Concrete Subbase
- Publication no: ATS-3520-25
- Published: 5 March 2025
- Edition: 1.0
- PDF (free) Download
Austroads Technical Specification ATS 3520 sets out the requirements for the construction of lean-mix concrete subbase (LCS). It includes the requirements for constituent materials;
- concrete mix design;
- production and transport of concrete;
- concrete subbase paving;
- survey;
- sampling and testing; and
- conformity criteria.
The technical specification can also be downloaded as a Word document.
- 1. Scope
- 2. Referenced Documents
- 3. Definitions
- Abbreviations
- Symbols
- 4. Quality System Requirements
- 5. Materials
- Aggregates – General
- Fine Aggregate
- Coarse Aggregate
- Alkali-Aggregate Reactivity
- Combined Aggregate Particle Size Distribution
- Cementitious Materials
- Water
- Admixtures
- Curing Compounds
- Steel Reinforcement (for Subgrade Beam)
- 6. Design of Concrete Mixes
- General
- Cementitious Content
- Compressive Strength
- Consistence
- Shrinkage
- Other Concrete Attributes
- Trial Mixing for Mix Design
- Submission of Nominated Mixes
- Change to Authorised Nominated Mix
- 7. Production and Transport of Concrete
- General
- Production Mixes
- Production Monitoring
- Measurement of Mixing Time
- Minimum Mixing Time
- Maximum Mixing Time
- Admixture Addition
- Discharge
- Transport of Concrete
- Consistence (Slump) of Concrete
- Minimum Frequency of Routine Consistence Testing
- Retempering
- Forming Time
- Air Content of Concrete
- 8. Concreting Personnel
- General
- Paving Supervisor
- Paving Crew
- 9. Subgrade Beam
- General
- Steel Reinforcement
- Concrete for Subgrade Beam
- Curing and Protection from Damage
- 10. Subbase Concrete Paving
- General
- Traceability
- Temperature and Weather Condition
- Slipform (Mechanical) Paving
- Paving Equipment
- Fixed-Form (Manual) Paving
- Paving in Transition Zones
- Joints and Edges
- Prevention of Moisture Loss
- Surface Finish
- 11. Curing
- General
- Curing Times
- Respraying
- Curing Compound Types
- Equipment
- Application Rate
- Verification of Application Rate
- Conformity of Application
- Wet Curing
- 12. Concrete Paving Trial
- General
- Assessment and Reporting
- Acceptance of Trial Section
- New Trial Section
- 13. Protection of Work
- Temperature
- Rain
- Trafficking of Subbase
- 14. Surface Debonding/Bonding Treatment
- General
- Types of Debonding/Bonding Treatments
- Times for Treatment
- Surface Preparation and Repair Treatment
- Cutback Bitumen and Bitumen Emulsion Seals
- Wax Emulsion (Under Concrete Base)
- 15. Survey
- General
- Survey of Underlying Surface Levels
- Survey of LCS Finished Surface Levels
- Alignment
- Surface Profile
- 16. Conformity – Concrete Cracking
- Types of Concrete Cracking
- Crack Assessment
- 17. Conformity – Concrete Compressive Strength
- Sub-Lot Delineation
- Test Groups
- Location and Frequency of Coring
- Test Specimens
- Correction Factors
- Acceptance of Sub-Lots with Core Compressive Strength Deficiency
- 18. Conformity – Thickness
- General
- Thickness Determination from Survey
- Thickness Determination from Cores
- Discrepancy Between Thickness from Survey and Cores
- Mean Thickness
- Conformity for Thickness
- Acceptance of Sub-Lots with Thickness Deficiency
- Offsetting Subbase Thickness Deficiency With Increased Base Thickness
- 19. Conformity – Alignment, Levels and Surface Profile
- Alignment
- Surface Levels
- Surface Profile
- 20. Redesign of Pavement Levels
- Redesign by the Contractor
- Redesign by the Principal
- 21. Restoration of LCS After Coring
- 22. Removal and Replacement of Lean-Mix Concrete Subbase
- Boundaries of Section for Removal
- Sawcutting
- Replacement
- Annexure A: Summary of Hold Points, Witness Points and Records
- Annexure B: Mixer Uniformity Testing
- B1 General
- B2 Stationary Mixer
- B3 Mobile Mixers
- Annexure C: Paving Trial Report
- Annexure D: Minimum Frequency of Testing
- Amendment Record
Related publications
ATS-3110-26
ATS-3145-26
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