Pavement
- Publication no: AP-T325-17
- ISBN: 978-1-925671-00-1
- Published: 15 August 2017
- PDF (free) Download
This report presents the findings of Austroads Project AT1540 Understanding the impact on pavement surfaces from next generation freight vehicles and developing practical network prediction models and responses. The main purpose of the project was to gain an improved understanding of the failure mechanisms that are particular to the pavement surfacing layer – as distinct from the structural layer – that may be caused by changing configurations and loadings of freight vehicles.
The project led to the development of the Surface Wear Tester (SWT), which was demonstrated as capable of applying sufficiently high levels of horizontal force to a surfacing (with emphasis on sprayed seal surfacings) to allow comparative testing to be undertaken for a range of binder types and operating conditions.
Possible amendments to the current prescriptive performance based standard for horizontal load are discussed. Avenues for further work are presented.
- Summary
- 1. Introduction
- 2. Sources of Horizontal Stress and Factors Contributing to Surfacing Performance
- 2.1. Sources of Horizontal Stress
- 2.1.1. Braking
- 2.1.2. Traction – Acceleration
- 2.1.3. Turning Movements
- 2.2. Factors Contributing to Surfacing Performance
- 2.2.1. Influence of Temperature
- 2.2.2. Influence of Binder
- 2.2.3. Influence of Seal Type and Condition
- 3. Performance Based Standards (PBS) Project and Follow-up Work
- 3.1. Development of a PBS Approach to the Regulation of Heavy Vehicles
- 3.1.1. PBS Standard for Horizontal Tyre Force
- 3.1.2. Review of Technical Basis of Standard for Horizontal Tyre Force
- 4. Quantifying the Stresses at the Tyre/surface Interface and the Resulting Performance Impacts
- 4.1. Systems for the Assessment of Horizontal Shear Force
- 4.1.1. Measurement Technology
- 4.1.2. Surface Selection Criteria
- 4.1.3. Laboratory Testing
- 5. Impact on Pavement Surfaces from Next Generation Freight Vehicles
- 5.1. Preliminary Sprayed Seal Selection Guide
- 5.2. Literature Review of Existing Facilities and Equipment
- 5.2.1. Pavement Modelling and Wear Measurement
- 5.2.2. Pavement Effect on Tyre Forces
- 5.2.3. Measurement of Tyre/Pavement Force
- 5.2.4. Summary
- 5.3. Tyre Types
- 6. Review of Existing Wear Measurement Technologies
- 6.1. Existing Systems
- 6.1.1. Stationary Laser Profiler (SLP)
- 6.1.2. Stereo Photographic Surface Imaging
- 6.1.3. QuickSURF
- 6.1.4. Sand Patch
- 6.2. Proposed Wear Measurement Technology: STL Device
- 6.2.1. Commissioning of STL device
- 6.3. Problems Encountered with STL
- 7. Development and Initial Commissioning of Surface Wear Trailer (SWT)
- 7.1. Development of SWT
- 7.1.1. Specification for SWT
- 7.1.2. Estimated Cost of SWT
- 7.1.3. Final Design and Manufacture of SWT
- 7.2. Initial Commissioning of SWT
- 7.2.1. Equipment Commissioning Trial
- 7.2.2. Initial Pavement Wear Trial
- 7.2.3. Summary
- 8. Field Trial: Nar Nar Goon
- 8.1. Site Set-up
- 8.2. Test Conditions
- 8.3. Data Collection
- 8.3.1. Vertical Loading
- 8.3.2. Slip Angle of Test Tyres and Lateral Load
- 8.3.3. Slip Ratio and Longitudinal Load
- 8.4. Test Program
- 8.5. Results
- 8.5.1. Loading Condition 1 (Passes 1 to 5)
- 8.5.2. Loading Condition 2 (Passes 6 and 7)
- 8.5.3. Loading Condition 3 (Passes 8 and 9)
- 8.5.4. Repeatability of Test Conditions
- 8.6. Comparison with Simulation
- 8.7. Surface Wear Measurements
- 8.7.1. Surface Topography Laser (STL)
- 8.7.2. Stereo Photographic Unit (DALEK)
- 8.8. Summary
- 9. Follow-up Field Trials in 2015
- 9.1. Effect of Temperature on Surface Integrity
- 9.1.1. Test Conditions
- 9.1.2. Results
- 9.1.3. Summary
- 9.2. Comparison of Binder Performance
- 9.2.1. Results
- 9.2.2. Method for Measuring Stone Loss
- 9.3. Summary
- 10. Field Work Program: March – July 2016
- 10.1. Purpose of Fieldwork
- 10.2. Sites
- 10.2.1. Site Selection
- 10.2.2. Site Setup
- 10.3. Experiment Design
- 10.3.1. Surface Calibration Testing
- 10.3.2. Destructive Testing
- 10.4. Testing in Victoria
- 10.4.1. Environmental Conditions during Testing
- 10.4.2. Experimental Results
- 10.5. Testing in Queensland
- 10.5.1. Environmental Conditions during Testing
- 10.5.2. Experimental Results
- 10.6. Analysis of Results (Victoria and Queensland)
- 10.6.1. Horizontal Force
- 10.6.2. Surface Texture
- 10.6.3. Aggregate Loss
- 10.6.4. Overall Performance
- 11. Horizontal Force Standard for PBS
- 11.1. Turning Movements
- 11.2. Accelerating, Braking and Climbing
- 12. Conclusion
- References