1. Karl Zipf DelDOT February 2014
Grading Asphalt Binders with the Multiple Stress Creep Recovery Test AASHTO TP-70 and MP-19 “The Future is Coming”
Karl Zipf
DelDOT
February 2014

2. WARNING

3. Brief History of the Test
DTFH61-08-H-0003 – Cooperative Agreement between the FHWA and the Asphalt Institute
John A. D’Angelo (FHWA)
Asphalt Binder ETG
Member Companies of the Asphalt Institute – Technical Advisory Committee

4. The present test methods for asphalt binder grading do not adequately characterize rutting or polymer-modified asphalts (PMA).
The current PG System (AASHTO M-320) is blind to modification and requires PG plus tests such as Elastic Recovery to characterize PMA binders.

5. The PG system was supposed to reduce rutting but over the past decade and a half it has not

6. The New Asphalt Binder Test
Uses the DSR which labs already have.
Runs the sample 10 times. Load and relax.

7. MSCR Test Data
The test gives two values which are the basis of the standards, TP-70 and MP-19.
Jnr – Nonrecoverable creep compliance for 10 cycles at a creep stress of 3.2 kPa
% Average Recovery at a creep stress of 3.2 kPa

8. The New Asphalt Binder Test

9. What’s in a Name SHRP (Sharp) – Strategic Highway Research Program
ISTEA (Ice Tea) – Intermodal Surface Transportation Equality Act
TWG (Twig) – Technical Working Group
MSCR (???) – Multiple Stress Creep Recovery

10. “MASCAR”
Sounds like NASCAR

11. “Massacre”
Like in the Boston Massacre

12. “Mascara”
Both asphalt and mascara are black

13. “Muskrat”
Multiple Stress Creep Recovery Test

14. Jnr Limits are Based on Rut Data
The Jnr (Nonrecoverable Compliance) correlated to rut depth in the ALF track, field studies and lab tests.
The Jnr will used to determine the binder grade.
Jnr works for both modified and non-modified binders.

15. MSCR % Recovery & Modification
Many processes will stiffen and binder but not all make them elastic.
The % Recovery is used to characterize the elasticity from polymer modification.
A polymer curve was developed based on data from available PMA binders.

16. Polymer Modification Curve
Currently in TP-70, will move to MP-19

17. So Far So Good Jnr % Recovery So how do you grade a binder?
Two key values for the MSCR test
These will determine the binder grade and whether it can be called a PMA binder.
Jnr
% Recovery
So how do you grade a binder?

18. Like PG System, Grade Based on LTPP Climate Temperature

19. Looks Familiar
USDA Plant Hardiness Zone Map

20. Northeast States LTPP High, Low and USDA

21. M-320 & MSCR Nomenclature Right now it now it looks like the PG System
The BIG change is that everything is based on the LOCAL high temperature environment.
Our environment is 64C and our standard grade, like the PG system is PG
Other grades, PG 70, and PG 76 will be tested at 64C as PG 64(something), based on the Jnr.
Binder name becomes state/region dependent.

22. MSCR and Low Temperature
The low temperature tests and nomenclature will not change with MSCR.
It still uses the BBR results.
The mid temperature criteria, the 8 mm DSR test, will have 6000 kPa as a cutoff for the stiffer grades, since for DelDOT the test temp will be 25C.

23. MP-19 Grades at 64C Jnr = 2.0 – 4.0 = PG 64S-22 “Standard” = PG 64-22
Jnr = 1.0 – 2.0 = PG 64H-22 “Heavy” = PG 70-22
Jnr = 0.5 – 1.0 = PG 64V-22 “Very Heavy” = PG 76-22
Jnr = 0.25 – 0.5 = PG 64E-22 “Extreme” = PG 76-22
Note MP-19 uses “High” & “Heavy” interchangeably
Standard “S” = traffic < 10 million ESALs, > 70 km/h
Heavy “H” = traffic million ESALs, km/h
Very Heavy “V” = traffic > 30 million ESALs, < 20km/h
Extreme “E” > 30 million ESALs, < 20km/h, toll plazas

24. Polymer Curve & DelDOT Data

25. Where the New Grades Fall at 64C

26. When Will DelDOT See MP-19?
The FHWA is pushing the MSCR test ASAP.
The Asphalt Institute is pushing the MSCR test.
The NEAUPG (Northeast Asphalt User-Producer Group) is reviewing a limited regional implementation for maybe 2014.
NEAUPG will be polymer curve in 2014, and non-PMA in a future year.
SEAUPG will consider it in 2015, central USA later, and west coast probably not at all.
National implementation date is unknown.

27. DelDOT M-320 vs MP-19 Grades PG 58-28 = PG 58S-28, Jnr 2.0 – 4.5 58C
PG = PG 64H-22, Jnr 1.0 – C
No Grade = PG 64V-22, Jnr 0.5 – C
For 2014 ?
PG = PG 64E-22, Jnr < C and meet polymer elasticity curve.

28. DelDOT and PG as MSCR
64V
64E

29. NEAUPG & PMA
From Maine to Maryland there will probably be two standard grades, PG 58S & PG 64S.
NYDOT will switch over all grades around Sept 2014 to MP-19.

30. MSCR and RAP
Like the PG System, M-320 the MSCR spec, MP-19 is based on 100% virgin binders.
RAP is stiff, Jnr , but not elastic so will fail the polymer curve.
RAP affects the low temperature properties, and these rules have not changed, and it is the low temperature where one sees failure.

31. August 2014
The MSCR Test AASHTO TP-70 will be a full standard AASHTO T-350
The MSCR Binder Grading AASHTO MP-19 will be a full standard, AASHTO M-322.

32. The End (Not really. There will probably be more next year.) Questions?

33. Implementing a New Standard