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

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

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

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

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 18-02-xx sample arrived too late for testing.

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

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

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.”

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

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

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).

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 100-250 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.

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

EPG High Temperature: Effect of Recovery 18-04-03 CRS-2P 18-10-02 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.

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. 18-04-02 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.

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.

EPG Intermediate Temperature

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 61-31 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 67-25 and EPG 61-19, Both are L samples. Function of formulating to the current specification?

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. 18-10-01, 18-10-02, and 18-10-03 were all lab created. Have to confirm, but suspect that all three were the same base asphalt binder. Average G* values were 10.8. 7.6, and 14.8 MPa respectively. Note that the 14.8 MPa value for the 18-10-03 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).

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.

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

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 09-50 study may need to be re-evaluated for low traffic applications. 2.2

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.

Alternate High Temperature: MSCR

Alternate High Temperature: MSCR

Alternate High Temperature: MSCR

Alternate Polymer Identification: MSCR

Alternate Polymer Identification: MSCR

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

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

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

2018 ETF Testing Program Some Key Takeaways from the Analysis MSCR limits suggested by NCHRP 09-50 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 09-50 research How much will change when formulations change to adapt to new specification?

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%

Thanks! Questions or Comments? Mike Anderson Asphalt Institute 859.288.4984 office manderson@asphaltinstitute.org