1. AASHTOWare Pavement-ME Design Software: Materials Libraryby
Murugaiyah Piratheepan
Western Regional Superpave Center – WRSC
University of Nevada Reno – UNR
Nevada Transportation Conference
April 10, 2013

2. Outline Background M-E design process
Statistical evaluation of laboratory test data
Calibration of performance models
Distress data collection
Acknowledgement

3. Background AASHTO 93 design guide 1950’s AASHTO road test
10-20 times less traffic
One geographical location
One type of subgrade and HMA
Short duration of the test
Refined in 1986 and 1993
Based on structural number (SN)
Relates the thickness of surface layer to serviceability.

4. Background Need for transition Incorporate higher traffic level
Climatic variations
New materials (HMA, WMA, PM binder) and their properties into the design.
Higher emphasis on performance
Higher emphasis on rehabilitation
Budgetary constraints and environmental concerns

5. Background
M-E design- Determines pavement responses through mathematical models and relates them to observed performance.
LTPP since 1987
Uses significant material properties
Considers month by month aging of materials
Can provide limitations for distresses
Reduce Life Cycle costs

6. Why Pavement-ME for Nevada?
Nevada use of Polymer modified asphalt binder
National performance models are calibrated based on neat asphalt binder only
Using the national models will show an early failure compared to the true performance of PM binders
This may result in unneeded thicker pavement section
Pavement-ME need to be locally calibrated to NV conditions

7. M-E design process Stage 1: Input Values
Stage 2: Structural/Performance Analysis
Stage 3: Engineering and Life Cycle Cost Analysis

8. M-E design process (Cont..)
Stage 1: Input Values
Level 1: Highest accuracy, requires laboratory or field testing and site specific data
Level 2: Intermediate accuracy, user selected data from database or estimated correlations
Including new materials such as WMA, RAP, and bio asphalt
Level 3: Lowest accuracy, typical averages or default values

9. M-E design process (Cont..)
Stage 1: Input Values
Materials
Traffic
Climate
68 sections

10. Stage 1: Input Values-Materials
M-E design process (Cont..)
Stage 1: Input Values-Materials
17 binders (14 PG64-28 & 3 PG76-22)
Dynamic Shear Rheometer (DSR)
Complex Shear Modulus (G*) and phase angle (δ)
Binder viscosity temperature relationship (A-VTS)

11. Stage 1: Input Values-Materials
M-E design process (Cont..)
Stage 1: Input Values-Materials
26 Contracts (16 PG64-28 & 10 PG76-22) for Dynamic Modulus
Sinusoidal axial compressive stress
Recoverable axial strain response
Run at 4 temp (40,70,100,130°F) & 6 freq (25,10,5,1,0.5,0.1 Hz)
Master Curve using time-temperature superposition
Master curve coefficients
Time
Stress
Strain
time shift = /
 = 0sin(ωt)
 = 0sin(ωt-) 0 0

12. Stage 1: Input Values-Materials
M-E design process (Cont..)
Stage 1: Input Values-Materials
17 Contracts (13 PG64-28 & 4 PG76-22) for Repeated Load Triaxial (RLT) test – Permanent Deformation Model
Pulse load (0.1 s loading and 0.6 s rest period)
Deviatory stress of 45psi and confinement of 30psi
Permanent & resilient strain with cyclic stress
3 different temperatures (104, 114.8, & 136.4°F)

13. Stage 1: Input Values-Materials
M-E design process (Cont..)
Stage 1: Input Values-Materials
8 Contracts (3 Pg64-28 & 5 PG76-22 )for beam fatigue test – Fatigue Performance Model
Cyclic haversine load at 10Hz
50% reduction in initial stiffness
3 temperatures (55,70, & 85°F) 3 strain levels

14. Stage 2: Structural/Performance Analysis
M-E design process (Cont..)
Stage 2: Structural/Performance Analysis

15. Stage 2: Structural/Performance Analysis
M-E design process (Cont..)
Stage 2: Structural/Performance Analysis

16. Statistical evaluation of laboratory test data
Groupings created to provide NDOT with appropriate Pavement ME design inputs
Binder viscosity
Dynamic modulus
Rutting model coefficients
Fatigue model coefficients

17. Statistical evaluation of laboratory test data
Each measured parameter was checked for possible groupings based on:
Nevada as a whole
Districts
Binder Grade (PG64-28 & PG76-22)
Binder Source (7 total)
Aggregate Source (17 total)

18. Statistical evaluation of laboratory test data
Binder Viscosity
Groupings
District 3
PG76-22 binders
Binder Sources Paramount and Valero
Average A-VTS
Average G* and δ for each assigned group
Groupings A VTS
PG76-22NV
District
Binder Source
Valero
Paramount

19. Statistical evaluation of laboratory test data
Dynamic Modulus
Groupings
Districts 2 & 3
binder sources
Aggregate sources
Average E* values provided for each group
Paramount Grouping
Temp. (°F)
Mixture |E*|, ksi
25 Hz
10 Hz
5 Hz
1 Hz
0.5 Hz
0.1 Hz 40
1737.1
1558.4
1416.3
1077.5
934.7
632.1 70
705.5
549.4
446.4
261.0
203.4
111.6
100
176.5
125.3
96.5
53.4
42.0
25.4
130
50.0
36.7
29.4
18.8
15.9
11.6

20. Statistical evaluation of laboratory test data
Rutting model
Groupings
District 3
Aggregate Source
Binder Sources
Average regression coefficients provided for each group
Paramount Grouping K1 K2 K3
2.4577
0.3276

21. Statistical evaluation of laboratory test data
Fatigue model
Groupings
NV as a whole
PG76-22 mixtures
Average regression coefficients provided for each group
PG76-22 Grouping K1 K2 K3 C
5.028
2.307
0.001

22. Calibration of performance models
Need to incorporate polymer modified binders
Need to consider new materials that performs better to local environmental conditions
Need to incorporate preservation and maintenance, construction for rehabilitation and new construction
Local calibration allows for factors in that area to be factored into the pavement ME indirectly

23. Calibration of performance models
Rutting model

24. Calibration of performance models

25. Distress data collection
Challenges in collecting measured distresses
Convert PMS data to pavement ME measuring units
New versus Rehabilitated sections
Properties for base, sub-baselayers

26. Calibration of performance models

27. Acknowledgement Tireless support from NDOT is gratefully acknowledged.
Professors and graduate students in Pavements/Materials program at UNR are thanked for the accomplishment.

28. Thank you