1. ETF Emulsion/Residue Testing Program
Andrew Hanz, Codrin Daranga
AASHTO TSP•2 – Emulsion Task Force (ETF) Meeting
Heritage Research Group – The Center
Indianapolis, IN
June 12-13, 2019

2. ETF Testing Program
The principal goals of the 2017 ETF Testing Program were to:
Determine appropriate procedures to be used for high and low temperature rheological properties
Determine the need for long-term aging
Evaluate procedures intended to ensure the quality of polymer modification without excluding good performers
The principal goal of the 2018 ETF Testing Program was to:
Evaluate the draft specification refined from the 2017 ETF Testing Program

3. ETF Testing Program Thanks!
The suppliers of the asphalt emulsion samples
The testing labs
Codrin Daranga and Shelly Cowley, Paragon Technical Services
Cristian Clopotel, Marathon Petroleum
Andrew Hanz, MTE Services
Amy Morhart and Darren Anweiler, Husky
Tim Reece and Jason Wielinski, Heritage Research Group
Texas A&M University
Dr. Amy Epps-Martin, Dr. Edith Arambula, and team
North Carolina State University
Dr. Richard Kim, Dr. Cassie Hintz, and team
Mike Voth, FHWA – Central Federal Lands
Wes Cooper, Asphalt Institute Binder Lab Manager

4. ETF Testing Program Samples Identification Year – UPG – Sample ID 18
01 (Pacific)
02 (Rocky Mountain)
03 (North Central)
04 (Southeast)
05 (Northeast)
06 (Canada)
10 (Lab) 01 . n

5. ETF Testing Program 2018 Samples # of Samples Type of Samples
Location(s) 4
CRS-2P
02, 03, 04, 10 3
CRS-2L
02, 04, 10
CRS-2
03, 04, 10 1
HFMS-2P 02
CRS-1hL 03
Only 3 CRS-2P samples were tested. The xx sample arrived too late for testing.

6. 2018 ETF Testing Program Tests on Residue from AASHTO R78, Procedure B
Tests on Residue from AASHTO T59, Section 7
Modified Samples Only

7. Residue Recovery AASHTO R78, Procedure B AASHTO T59, Section 7
“Recovering Residue from Emulsified Asphalt Using Low- Temperature Evaporative Techniques”
Thin film, silicone mat
Forced draft oven at 60°C for 6 hours
High and Intermediate temperature testing for performance grading
AASHTO T59, Section 7
“Emulsified Asphalt Residue by Evaporation”
Forced draft oven at 163°C for 3 hours
Modified asphalt emulsions only
High temperature testing for polymer identification

8. Residue Recovery Time from residue recovery to testing matters
Guidance provided to labs:
“Before recovering the asphalt emulsion, please ensure that the test procedures will be conducted on the recovered residue within 48 hours after recovery.”

9. 2018 ETF Testing Program High Temperature Testing on Recovered Residue
Determination of G*/sin δ
Testing Details
Perform in accordance with AASHTO T315
25-mm parallel plate geometry
1-mm gap
12% shear strain
Temperature sweep starting at 55°C and proceeding in 6°C increments until failure (the point where G*/sin δ is less than 0.65 kPa)
Report
G*/sin δ at each temperature
δ at each temperature
Tc,high – the continuous high temperature grade where G*/sin δ = 0.65 kPa
δ at Tc,high – the value of phase angle at the continuous high temperature grade

10. 2018 ETF Testing Program High Temperature Testing on Recovered Residue
Determination of MSCR Parameters
Testing Details
Perform in accordance with AASHTO T350
25-mm parallel plate geometry
1-mm gap
Test temperature at 3°C higher than LTPPBind Grade Temperature (as indicated with sample) and at 3°C lower than LTPPBind Grade Temperature
Use a new test specimen for each temperature
Report
Jnr0.1 and Jnr3.2 at each temperature
R0.1 and R3.2 at each temperature

11. 2018 ETF Testing Program
Intermediate-Low Temperature Testing on Recovered Residue
Determination of G* at critical phase angle, Gc
Testing Details
Perform in accordance with Research Draft Standard, “Determining Dynamic Shear Modulus of Emulsion Residues at Critical Phase Angle Values Using the Dynamic Shear Rheometer (DSR)” with exceptions as noted in italics below
8-mm parallel plate geometry
2-mm gap
1% shear strain
Frequency sweep at each temperature starting at 0.1 rad/s and proceeding to 100 rad/s using 10 loading frequencies per decade.
Three temperatures starting at 25°C, then proceeding to 15°C, and finally 5°C
Report
G* and δ at each temperature and frequency
Gc at critical phase angle (as indicated with sample) using analysis shown in Section 12 or through use of rheological software package (please indicate which approach was used).

12. EPG High Temperature
CRS-2 looks to be about the same high temperature grade regardless of the actual climate in which it is expected to be used. Probably due to formulating for current specifications (where a CRS-2 would have a Pen range of dmm, putting it in a PG 58-xx or softer grade).
Critical temperature by G*/sin δ appears to be slightly higher on average for P emulsions than L emulsions. HFMS-2P significantly higher.
High variability for some samples; more than would be encountered with standard DSR testing. To put it in perspective…the published multilab 1s% for an individual G*/sin d result by T315 is 6%. For the values around 0.65 – 1.00 kPa used to calculate Tc, the calculated 1s% for Tc would be 0.5C. This suggests that the recovery procedure may play a significant role in the results. Significantly low values may be indicative of incomplete recovery.

13. EPG High Temperature
Variability improved when AASHTO T59 Section 7 procedure was used for residue recovery. Range of 1s% was 1-3% for T59 Section 7 and 3-7% for R78 Procedure B

14. EPG High Temperature: Effect of Recovery
CRS-2P
CRS-2L
Line of equality shown. Distance from the line of equality indicates how much the Tc changes with recovery procedure. Highlighted data points are more than 6 degrees (one grade) different. AASHTO T59 procedure results in generally higher Tc values.

15. EPG Polymer Identification
All P samples pass with 80 degree maximum criterion.
All L samples pass with 84 degree maximum criterion. Lab 3 indicated that 3 of the 4 samples would also pass the 84 degree maximum criterion.
CRS-2 sample is close to the 84 degree criterion, with Labs 2 and 3 indicating passing results. These two labs also indicated much lower Tc values for this sample than Labs 1 and 5.

16. EPG Polymer Identification
AASHTO T59 Section 7 procedure generally lowers phase angle. Variability is substantially unchanged, but all samples/labs indicate passing at 80 degree maximum criterion with two exceptions (Lab 2, two L samples).
Not much change in average value for P samples. Was 73.8 degrees with R78 and 72.5 degrees with T59. Reduction of 1.3 degrees.
Larger change in average value for L samples. Was 81.3 degrees with R78 and 76.3 degrees with T59. Reduction of 5.0 degrees.

17. EPG Intermediate Temperature

18. EPG Intermediate Temperature
δc, degrees
G*, MPa
EPG 61-31 42
37.5
EPG 67-25 45
17.4
EPG 61-19 48
13.6
EPG 67-19
5.8
EPG 61-13 51
4.7
More difficult to meet G* at δc criterion as low temperature grade decreases. The two EPG were a CRS-2 and CRS-2P. The CRS-2P was only marginally better in G* value. Likely caused by same or similar low temperature grade. Same source. P sample could potentially use softer base binder depending on high temperature properties.
Only one sample each of EPG and EPG 61-19, Both are L samples.
Function of formulating to the current specification?

19. EPG Intermediate Temperature
Table showing G* at a common phase angle (45 degrees) to show how similar the likely-used base binder grades were in all samples , , and were all lab created. Have to confirm, but suspect that all three were the same base asphalt binder. Average G* values were , and 14.8 MPa respectively. Note that the 14.8 MPa value for the sample drops to 6.8 MPa if the one seemingly anomalous high data point is removed (Lab 3). This would show a slight improvement in intermediate temperature properties as a function of using latex (7.6 MPa) or SB/SBS polymer (6.8 MPa) compared to CRS-2 (10.8 MPa).

20. Alternate High Temperature: MSCR
Graph showing all MSCR Jnr-3.2 results as a function of G*/sin δ at the same temperature. Expected relationship shown.

21. MSCR Testing to Establish “S” Grade Criterion
4.5
Data from the study performed by AI to set the Jnr-3.2 criterion for S grades in AASHTO M332 using unmodified MRL asphalt binders from SHRP.
2.2

22. MSCR Testing to Establish “S” Grade Criterion
4.5
G*/sin δ, kPa
Est. Jnr-3.2, kPa-1
1.00
10.87
0.65
17.62
Using the equation and extrapolating back to G*/sin d values of 1.00 kPa and 0.65 kPa yields the Jnr-3.2 values shown in the table. Suggests that the 8.00 kPa-1 maximum from the NCHRP study may need to be re-evaluated for low traffic applications.
2.2

23. Alternate High Temperature: MSCR
As with the Tc determination, recovery of residue using AASHTO T59 results in higher Tc values and lower Jnr-3.2 values at the same temperature.

24. Alternate High Temperature: MSCR

25. Alternate High Temperature: MSCR

26. Alternate High Temperature: MSCR

27. Alternate Polymer Identification: MSCR

28. Alternate Polymer Identification: MSCR

29. 2018 ETF Testing Program Some Key Takeaways from the Analysis
Consistency in residue recovery is important to minimize variability
AASHTO R78, Procedure B has higher variability – particularly for high temperature results
AASHTO T59, Section 7 mitigates some of the variability, but changes the values

30. 2018 ETF Testing Program Some Key Takeaways from the Analysis
Phase angle limits for polymer identification generally separate modified from unmodified emulsion residues using AASHTO R78 Procedure B recovery
84-degree maximum generally segregates unmodified from modified residue
80-degree maximum generally segregates polymer modified (P) from latex modified (L) residues
AASHTO T59, Section 7 recovery appears to make all modified residues pass the criterion of 80 degrees maximum
Generally greater effect on latex modified residue than polymer modified residue

31. 2018 ETF Testing Program Some Key Takeaways from the Analysis
Intermediate temperature properties appear to be strongly impacted by low temperature grade
The lower the low temperature grade, the higher the G* at δc…regardless of whether the residue is unmodified or modified
Function of the base asphalt binder?
May see changes once formulations change to meet new specification

32. 2018 ETF Testing Program Some Key Takeaways from the Analysis
MSCR limits suggested by NCHRP may need to be re- evaluated
A G*/sin δ value of 0.65 kPa is comparable to a Jnr-3.2 value of approximately 17.6 kPa-1
Twice as high as the limit for low traffic from NCHRP research
How much will change when formulations change to adapt to new specification?

33. 2018 ETF Testing Program Some Key Takeaways from the Analysis MSCR
Jnr,3.2 variability still high
Not helped by variability in recovery procedure
Testing at temperature of EPG-6 appears more appropriate for discrimination of results
R0.1 at temperature of EPG-6 appears appropriate for discrimination of results
Average of CRS-2 residue = 4%
Average of CRS-2L residue = 42%
Average of CRS-2P residue = 57%

34. Thanks! Questions or Comments? Mike Anderson Asphalt Institute
office