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2. Outline What is the Asphalt Mixture Performance Tester?
Why was it developed?
What tests can be conducted?
How can I use the data?
What’s next?
3. What is the AMPT? NCHRP 9-29
Servo-Hydraulic Machine
HMA Testing
Mix Design
Structural Design
Evaluation I also think that it is appropriate to acknowledge various groups that have contributed to the information that I will present today.
First the agencies that have sponsored and guided the work that I will attempt to summarize, particularly the Federal Highway Administration and the various State Departments of Transportation. As major users of bituminous materials, they have sponsored most of the research associated with this material.
Second are all of colleagues that I have worked with on the National Cooperative Highway Research Program Projects 1-37A developing the AASHTO 2002 Pavement Design Guide, and Project 9-19 dealing with modeling asphalt mixture performance.
Finally, I would like to acknowledge the efforts of all those who have contributed to the the literature and our growing body of knowledge particularly in the areas of asphalt mixtures and pavement structural design. I also think that it is appropriate to acknowledge various groups that have contributed to the information that I will present today.
First the agencies that have sponsored and guided the work that I will attempt to summarize, particularly the Federal Highway Administration and the various State Departments of Transportation. As major users of bituminous materials, they have sponsored most of the research associated with this material.
Second are all of colleagues that I have worked with on the National Cooperative Highway Research Program Projects 1-37A developing the AASHTO 2002 Pavement Design Guide, and Project 9-19 dealing with modeling asphalt mixture performance.
Finally, I would like to acknowledge the efforts of all those who have contributed to the the literature and our growing body of knowledge particularly in the areas of asphalt mixtures and pavement structural design.
4. AMPT Capabilities Three Performance Related Tests
Dynamic Modulus
Repeated Load
Creep
Temperature Control
4 to 60 °C
With and Without Confinement
210 kPa Max
5. Key AMPT Features Rugged
Proven Hydraulic System
Automated Testing Cell
Temperature
Confining Pressure
Easy to Install Instrumentation
Standard Software
Testing and Analysis
Data Quality
Technician Friendly
6. Why Do We Need the AMPT? Test to Indicate How a Mix Will Perform
Rutting
Cracking
Uses
Identify Inferior Mixtures
Structural Design
Evaluations
7. SHRP Mixture Tests
8. Issues With SHRP Products
9. Post SHRP National Cooperative Highway Research Program (NCHRP)
Considered
Gyratory Compactor
Asphalt Pavement Analyzer
Fundamental Tests
10. Recommended Tests
11. Dynamic Modulus Test
12. Repeated Load Test
13. Creep Test
14. SPT Uses Dynamic Modulus Master Curve for Structural Design
AASHTO MEPDG
Mixture Design
NCHRP Project 9-33 “Mix Design Manual for Hot Mix Asphalt”
Material Evaluations
Homogenity of RAP Mixtures
15. Pavement Structural Design AASHTO Mechanistic-Empirical Pavement Design Guide
HMA Characterized by a Dynamic Modulus Master Curve
Plant Aged Conditions
Modulus Needed
Stress-Strain Analysis
Rutting Model
Fatigue Cracking Model
17. NCHRP 9-29 Draft Practice Developing Dynamic Modulus Master Curves for Hot-Mix Asphalt Concrete Using the Asphalt Mixture Performance Tester
Testing Conditions
Temperature
Frequency
Replicates
Data Analysis
Excel Spreadsheet
18. Rutting Resistance Shear Deformation - Major
Densification - Minor
High Temperatures
Early in Pavement Life
19. Repeated Load Test
20. NCHRP 9-33 Tentative Criteria Stress Level
600 kPa (87 psi)
Database of Mixtures Tested by FHWA
Temperature
50 % Reliability Design Temperature From LTPPBind 3.1
Short Testing Time
21. NCHRP 9-33 Tentative Criteria
22. Mixture Homogenity How Well Does the RAP/RAS Binder Mix with the New Binder?
Black Rock
Complete Mixing
23. One Tool Dynamic Modulus
Test Is Highly Sensitive to Binder Stiffness
Assess Degree of Mixing of New and Recycled Binders
Relatively Easy to Perform with the AMPT
24. How? Perform Dynamic Modulus Tests on Plant Produced Mixture
Plant Mixed Condition
Recover Binder, Test and Estimate Dynamic Modulus Using Predictive Model
Fully Blended Condition
Compare Measured and Estimated
25. Good Mixing
26. Poor Mixing
27. Implementation Interlaboratory Study
NCHRP 9-29
Pooled Fund Study 5(178)
Purchase Equipment for Interested Agencies
2 Day Training Course
Coordinated Studies
Improve Criteria
28. AMPT Summary Specifically for HMA Testing
Three Performance Related Tests
Dynamic Modulus
Repeated Load
Creep
Fatigue Test Under Development
User Friendly, Second Generation Mixture Performance Testing Equipment
Extensive National Efforts to Develop and Implement
29. AMPT Uses Dynamic Modulus Master Curve for Structural Design
AASHTO MEPDG
Mixture Design
NCHRP Project 9-33 “Mix Design Manual for Hot Mix Asphalt”
Material Evaluations
Homogenity of RAP Mixtures
Forensics
Others
30. Questions