Pavement
- Publication no: AP-T33-04
- ISBN: 0 85588 709 5
- Published: 1 January 2004
- PDF (free) Download
This report records the work undertaken in the development of Pavement Design – A Guide to the Structural Design of Road Pavements, initially published by the National Association of Australian State Road Authorities (NAASRA) in 1987 and subsequently revised and re-issued by Austroads in 1992. It briefly describes the predecessor and progenitor – the Interim Guide to Pavement Thickness Design (NAASRA 1979) – and then proceeds to review the technical issues encountered, and the solutions adopted, in the formulation of the Guide.
This material presented in the Guide represented many years of development in Australia and overseas in design procedures for flexible pavements for highway traffic. The Guide was developed by a series of (then) NAASRA Working Groups representing both the members of NAASRA and industry. Note that the names of the various Road Authorities relevant at the time (rather than the current names) are used throughout this report.
This report does not address the origins of Chapter 9 of the 1992 Guide – the Design of Rigid Pavements – which is the subject of another report in this document (Part 2).
- 1. INTRODUCTION
- 2. SETTING THE SCENE
- 2.1. The Interim Guide to Pavement Thickness Design
- 2.1.1. Format of the IGPTD
- 2.1.2. Release of the IGPTD
- 2.2. Establishment of a Working Group to Revise the IGPTD
- 2.2.1. A Guide – not a Manual
- 3. GRANULAR PAVEMENTS WITH THIN BITUMINOUS SURFACINGS
- 3.1. Origins of the CBR-Thickness-Traffic Chart
- 3.1.1. Quality of Pavement Material and its Cover Requirements
- 3.1.2. Concluding Comments
- 3.2. Terminal Condition
- 3.2.1. Modification of Terminal Condition
- 3.2.2. Implicit Model for Roughness Progression
- 4. DEVELOPMENT OF THE MECHANISTIC PROCEDURE
- 4.1. Broad Issues
- 4.2. Elastic Characterisation
- 4.2.1. Isotropic or Anisotropic Characterisation?
- 4.2.2. Values for Poisson’s Ratios
- 4.2.3. Relationship between Subgrade Modulus and CBR
- 4.2.4. Typical Modulus Values
- 4.2.5. Stress Regimes for Triaxial Testing of Granular Materials
- 4.2.6. Sub-Layering of Granular Materials and Assignment of Moduli
- 4.2.7. Modulus of Top Sub-Layer of Granular Material
- 4.2.8. Modulus of Granular Material Overlying a Cemented Layer
- 4.2.9. Relationships between Modulus and UCS for Cemented Materials.
- 4.2.10. Characterisation of Cracked Cemented Materials
- 4.3. Performance Relationships
- 4.3.1. Subgrade Strain Criterion
- 4.3.2. Fatigue Cracking of Cemented Material
- 4.3.3. Fatigue Relationship for Asphalt
- 4.4. Design Traffic
- 4.4.2. Derivation of “Standard Axle (or Traffic) Factors”
- 4.4.3. Cumulative Growth Factor for Estimation of Design Traffic
- 4.5. Incorporation of Location-Specific Temperature Regime
- 5. DEVELOPMENT OF OVERLAY DESIGN PROCEDURE
- 5.1. Design Deflection Curves
- 5.1.1. Adoption of IGPTD Curve 1
- 5.1.2. Adoption of IGPTD Curve 4
- 5.2. The Curvature Function
- 5.3. Temperature Correction for Deflection and Curvature
- 5.4. Reduction in Deflection Parameters due to Overlay Placement
- 5.4.2. Reduction in Maximum Deflection (at 25C) due to an Asphalt Overlay
- 5.4.3. Reduction in Curvature Function due to an Asphalt Overlay
- 5.5. Adjustment of Asphalt Overlay Thickness to Allow for Locality Temperature
- REFERENCES