Pavement
Guide to Pavement Technology Part 4B: Asphalt
- Publication no: AGPT04B-25
- ISBN: 978-1-922994-87-5
- Published: 17 September 2025
- Edition: 3.0
- PDF (free) Download
This Guide is part of the Austroads Guide to Pavement Technology and introduces the nature of asphalt as a construction material and its application in road pavements. It also provides guidance for constituent material selection, as well as the design, manufacture, placement and testing of commonly used asphalt mix types.
The first edition was published in May 2007 and the Guide received a major update in 2014. This third edition captures the advancements made in asphalt technology over the past decade, including the increased use of more sustainable materials, improvements in constituent materials and asphalt characterisation testing and the adoption of more performance-related mix design procedures and testing.
The Guide also provides a comprehensive list of references that include background and supporting information related to asphalt materials, testing and construction.
Watch a recording of the webinar to learn more.
Edition 2.0 of the Guide includes:
- additional guidance related to the use of recycled materials in asphalt and asphalt sustainability
- new guidance for the design of crumb rubber gap-graded asphalt and EME2
- the latest developments in asphalt performance testing.
- 1. Introduction
- 1.1General
- 1.2 Sustainable asphalt
- 2. Asphalt Applications and Mix Types
- 2.1 Applications
- 2.2 Design of new pavements
- 2.3 Structural performance of asphalt
- 2.4 Rehabilitation
- 2.4.1 General
- 2.4.2 Treatment types
- 2.5 Operational environment factors
- 2.6 Types of asphalt mixes
- 2.6.1 General
- 2.6.2 Dense-graded asphalt
- 2.6.3 Stone mastic asphalt
- 2.6.4 Open-graded asphalt
- 2.6.5 Crumb rubber gap-graded asphalt
- 2.6.6 Fine gap-graded asphalt
- 2.6.7 EME2
- 2.7 Asphalt courses
- 2.7.1 General
- 2.7.2 Wearing surface
- 2.7.3 Intermediate course
- 2.7.4 Basecourse
- 2.7.5 Regulating, levelling or corrective course
- 2.8 Mix size and layer thickness
- 2.8.1 Nominal mix size
- 2.8.2 Layer thickness
- 2.8.3 Ultra-thin asphalt surfacing
- 2.9 Warm mix asphalt
- 3. Asphalt Materials
- 3.1 Introduction
- 3.2 Aggregates
- 3.2.1 Sources of aggregate
- 3.2.2 Aggregate properties
- 3.2.3 Reclaimed asphalt pavement
- 3.2.4 Other recycled materials
- 3.3 Filler
- 3.4 Binders
- 3.4.1 Bitumen
- 3.4.2 Multigrade bitumen
- 3.4.3 Modified binders
- 3.4.4 Epoxy-modified bitumen and polyurethane materials
- 3.4.5 Cutback bitumen
- 3.4.6 Bituminous emulsion
- 3.5 Additives
- 3.5.1 General
- 3.5.2 Adhesion agents
- 3.5.3 Warm mix additives
- 3.5.4 Fibres
- 3.5.5 Natural modifiers
- 3.5.6 Rejuvenating agents
- 3.5.7 Coloured pigments
- 4. Asphalt Mix Design
- 4.1 Introduction
- 4.1.1 General
- 4.2 Mix design process
- 4.2.1 Background
- 4.2.2 Selection of mix type and component materials
- 4.2.3 Recipe criteria
- 4.2.4 Preparation and compaction of trial mixes
- 4.2.5 Volumetric properties
- 4.2.6 Mechanical properties
- 4.2.7 Workability
- 4.2.8 Job mix
- 4.2.9 Implementation and verification of mix properties
- 4.3 Volumetric properties
- 4.3.1 General
- 4.3.2 Determining the density of components
- 4.3.3 Bulk density of asphalt
- 4.3.4 Maximum density
- 4.3.5 Voids in mineral aggregate
- 4.3.6 Air voids
- 4.3.7 Binder content
- 4.3.8 Voids filled with binder
- 4.3.9 Binder film index
- 4.4 Mechanical testing
- 4.4.1 General
- 4.4.2 Modulus
- 4.4.3 Permanent deformation
- 4.4.4 Moisture sensitivity
- 4.4.5 Fatigue resistance
- 4.4.6 Particle loss
- 4.4.7 Water permeability
- 4.4.8 Marshall stability and flow
- 4.5 Combining component materials
- 4.5.1 Selecting a target grading
- 4.5.2 Maximising packing properties of dense graded mixes
- 4.5.3 Combining aggregates to a target grading
- 4.5.4 Characterising reclaimed asphalt pavement binders and designing binder blends to a specified viscosity value
- 4.6 Laboratory mixing and compaction of asphalt mixes
- 4.6.1 Sample preparation and conditioning
- 4.6.2 Laboratory compaction
- 4.6.3 Warm mix asphalt
- 4.7 Mix design procedure for dense-graded asphalt mixes
- 4.7.1 General
- 4.7.2 Improving mix performance
- 4.7.3 Modified binders
- 4.7.4 Reclaimed asphalt pavement
- 4.7.5 Cold mix
- 4.8 Mix design procedure for stone mastic asphalt
- 4.8.1 characteristics of stone mastic asphalt
- 4.8.2 Design procedure
- 4.8.3 Design requirements
- 4.8.4 Aggregates
- 4.8.5 Fillers and binders
- 4.8.6 Sample preparation
- 4.8.7 Measurement of bulk density
- 4.8.8 Binder drain-off
- 4.9 Mix design procedure for open-graded asphalt
- 4.9.1 Characteristics of open-graded asphalt
- 4.9.2 Design procedure
- 4.9.3 Design requirements
- 4.9.4 Aggregates
- 4.9.5 Fillers and binders
- 4.9.6 Sample preparation
- 4.9.7 Measurement of bulk density
- 4.9.8 Binder drain-off
- 4.9.9 Asphalt particle loss
- 4.10 Mix design procedure for crumb rubber gap-graded asphalt
- 4.10.1 Characteristics of crumb rubber gap-graded asphalt
- 4.10.2 Design procedure and requirements
- 4.11 Mix design procedure for fine gap-graded asphalt
- 4.11.1 Characteristics of fine gap-graded asphalt
- 4.11.2 Design procedure and requirements
- 4.12 Mix design procedure for EME2
- 4.12.1 Characteristics of EME2
- 4.12.2 Design procedure
- 4.12.3 Design requirements
- 4.1 Introduction
- 5. Asphalt Manufacture
- 5.1 Introduction
- 5.2 Types of mixing plants
- 5.2.1 General
- 5.2.2 Sites for mixing plants
- 5.3 Raw material supply and storage
- 5.3.1 Aggregate supply
- 5.3.2 Aggregate stockpiles
- 5.3.3 Stockpiling and handling of reclaimed asphalt pavement
- 5.3.4 Mineral filler storage
- 5.3.5 Binder storage
- 5.3.6 Storage of additives
- 5.4 Batch mixing plants
- 5.4.1 General
- 5.4.2 Cold aggregate bins
- 5.4.3 Cold aggregate feeding
- 5.4.4 Aggregate heating and drying
- 5.4.5 Dust extraction
- 5.4.6 Screening of hot aggregates
- 5.4.7 Hot aggregate bins
- 5.4.8 Filler feeding
- 5.4.9 Aggregate proportioning
- 5.4.10 Binder proportioning
- 5.4.11 Mixing
- 5.4.12 Controls
- 5.4.13 Reclaimed asphalt pavement
- 5.5 Continuous mixing plants
- 5.5.1 General
- 5.5.2 Parallel flow drum mixer
- 5.5.3 Counterflow drum mixer
- 5.5.4 Drum within a drum (double drum mixer)
- 5.5.5 Tandem drum mixers
- 5.5.6 Cold mixing plant
- 5.6 Warm mix asphalt
- 5.7 Asphalt surge and storage bins
- 5.8 Cold mix
- 5.9 Cold recycling of asphalt
- 5.10 Routine inspections
- 6. Asphalt Paving
- 6.1 Introduction
- 6.2 Planning
- 6.3 Weather conditions
- 6.4 Surface preparation
- 6.4.1 Cleaning
- 6.4.2 Correction of defects
- 6.4.3 Tack coating
- 6.5 Transport
- 6.6 Spreading
- 6.6.1 General
- 6.6.2 Material transfer vehicle
- 6.6.3 Spreading by asphalt paver
- 6.6.4 Joints
- 6.7 Compaction
- 6.7.1 General
- 6.7.2 Compaction equipment
- 6.8 Finished surface properties
- 7. Quality of Asphalt
- 7.1 Introduction
- 7.2 Control and monitoring of asphalt manufacture
- 7.2.1 Tests on raw materials
- 7.2.2 Production process
- 7.2.3 Sampling and testing
- 7.2.4 Statistical process control
- 7.3 Checklists
- References
- Appendix A Testing of Components
- A.1 Introduction
- A.2 Aggregates
- A.3 Fillers
- A.4 Binders
- A.4.1 Bitumen
- A.4.2 Modified binders
- Appendix B Mixing, Conditioning and Compaction of Samples for Density Testing
- B.1 General
- B.2 Prior to mixing
- B.3 Mixing
- B.3.1 General
- B.3.2 Raw materials
- B.3.3 Pre-mixing and material preparation
- B.3.4 Mixing of binder and aggregates
- B.4 Splitting of the mix
- B.4.1 General
- B.4.2 Cone and quartering
- B.4.3 Sample divider
- B.5 Conditioning
- B.6 Compaction
- B.6.1 Principles of gyratory compaction
- B.6.2 Gyratory compaction to a set density or to a set number of gyratory cycles
- Appendix C Measurement of Volumetric Properties
- C.1 Introduction
- C.2 Specimen requirements
- C.3 Equipment
- C.4 Calculation of volumetric properties
- C.4.1 Bulk density
- C.4.2 Maximum density
- C.4.3 Voids and Density Relationships
- C.5 Factors affecting volumetric properties
- C.6 Interpretation of results
- Appendix D Measurement of Resilient Modulus
- D.1 Introduction
- D.2 Specimen requirements
- D.3 Equipment
- D.4 Monitoring of test temperature
- D.5 Load duration
- D.6 Poisson’s ratio
- D.7 Factors affecting resilient modulus results
- D.8 Interpretation of results
- Appendix E Measurement of Permanent Deformation
- E.1 Introduction
- E.2 Specimen requirements
- E.3 Equipment
- E.4 Test procedure
- E.5 Monitoring of test temperature
- E.6 Specimen examination
- E.7 Factors affecting wheel tracking results
- E.8 Interpretation of results
- Appendix F Measurement of Moisture Sensitivity
- F.1 Introduction
- F.2 Specimen requirements
- F.3 Equipment
- F.4 Test procedure
- F.5 Interpretation of results
- Appendix G Measurement of Fatigue and Flexural Modulus
- G.1 Introduction
- G.2 Developments in measurement of the fatigue of asphalt mixes
- G.3 Specimen requirements
- G.4 Equipment
- G.5 Test Procedure
- G.6 Monitoring of test temperature
- G.7 Factors affecting flexural modulus and fatigue results
- G.8 Interpretation of results
- Appendix H Measurement of Particle Loss
- H.1 Introduction
- H.2 Specimen requirements
- H.3 Equipment
- H.4 Monitoring of test temperature
- H.5 Factors affecting particle loss results
- H.6 Interpretation of results
- Appendix I Measurement of Permeability
- I.1 Introduction
- I.2 Specimen requirements
- I.2.1 Laboratory compacted specimens
- I.3 Equipment
- I.4 Test procedure
- I.5 Factors affecting permeability results
- I.6 Interpretation of results
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