Pavement
- Publication no: AP-T292-15
- ISBN: 978-1-925294-37-8
- Published: 9 April 2015
- PDF (free) Download
Traffic loadings on Australia’s extensive sprayed seal network have increased, particularly with freight efficiency resulting in longer and heavier loads being transported by prime movers.
This report details the development of a model to describe how different axle loads and axle groupings combine to cause surface texture decay on a sprayed seal.
Development of the model relied on experimental data generated by the Australian linear accelerated loading facility. The model was then validated using another set of data generated by the New Zealand Canterbury Accelerated Pavement Testing Indoor Facility.
From the data, a load damage exponent of 1 for sprayed seal wear was calculated based on analysis of a dual tyre tandem axle traversing a sprayed seal. This suggests that the load damage to a sprayed seal is linear as opposed to the power function model currently used in pavement design.
The research findings can be used to investigate if the Austroads seal design method needs refinement in terms of equivalent heavy vehicles calculation.
- Summary
- Contents
- 1. Introduction
- 1.1. Objective of this Report
- 1.2. Nomenclature
- 1.3. Relationship to Previous Publications
- 2. Literature Review
- 2.1. Traffic
- 2.2. Equivalent Standard Axles
- 2.3. Pavement Load Damage Exponent
- 2.3.1. Summary
- 2.4. Predicting Seal Wear (Reduction in Macrotexture)
- 2.4.1. Summary
- 3. Experimental Design
- 3.1. Accelerated Loading Facility Experiment
- 3.2. Tyre and Axle Assembly Characteristics
- 3.3. Pavement
- 3.4. Sprayed Seal Surfacing
- 3.5. Experimental Design
- 3.6. Loading Regime
- 3.7. Limitations
- 3.7.1. Surface Texture Measurement
- 3.7.2. Construction Variability
- 3.7.3. Loading was Accelerated but Binder Aging was Not
- 3.7.4. Velocity of ALF
- 4. Data
- 4.1. Raw Data
- 4.2. Data Analysis
- 4.2.1. Approximating Initial SPTD
- 4.2.2. Weibull Models
- 4.2.3. Individual Model Predictions
- 4.2.4. Determination of a Generalised Model
- 4.2.5. Statistical Significance Check of the Generalised Model
- 4.2.6. Results of the Generalised Model Prediction
- 4.2.7. Validation of the Generalised Model Using an Independent Data Set
- 5. Analysis of Equivalent Standard Axles (ESAs) and Standard Axle Repetitions (SAR)
- 6. Analysis of a Load Damage Exponent
- 7. Discussion
- 7.1. The Model
- 7.2. Equivalent Standard Axles
- 7.3. Load Damage Exponent for Sprayed Seals
- 7.4. Other Issues
- 8. Conclusions
- References
- Appendix A Comparison of ALF Loading Cycles to Real-life Traffic
- Appendix B Volumetric Sand Patch Texture Depth Data