1. Emulsion Task Force Meeting
Scrub Seal Update
Andrew Hanz
Mathy Construction
Emulsion Task Force Meeting
Indianapolis, IN
June 21, 2018

2. Subcommittee Membership
Codrin Daranga
Andy Clayton
Hussain Bahia
Ken Gryzbowski
Jeff Schoger
Kevin Carlson
Katy Fleury

3. Why have a specification?
Scrub seal is being used effectively throughout the US.
All based on proprietary specifications.
Universal specification
Reduces confusion
Promotes competition
Promotes innovation

4. Components of the Materials Spec
Polymer Modified Rejuvenating Emulsion
Emulsion
Emulsion Residue
Rejuvenating Agent
Polymer
Aggregate
Gradation
Quality Requirements

5. Why was the spec. pulled back
Why was the spec. pulled back? Emulsion Residue Properties – Polymer Identification
Original Proposed test was MSCR %R, 3.2kPa at 10C >55%.
Elastomeric Systems
Test could not differentiate between PMAs and CRS-2. Test temperature too low and material too stiff.
Solution: MSCR at 52°C and 0.1kPa
Non-Elastomeric Systems
MSCR or other elasticity test does not identify polymer presence.
Solution: TBD

6. Scrub Seal vs Conventional Chip Seal Emulsions
DSR at 52°C
MSCR
%R 0.1
%R 3.2
G*/sind
delta 10 52 58
CMS-2P
2.86 77
75.5%
29.9%
19.4%
68.3%
8.7%
3.0%
CRS-2
3.228
85.3
63.0%
4.2%
-0.4%
61.1%
0.8%
0.0%
CRS-2P
4.494
74.4
77.7%
48.7%
47.7%
69.8%
26.8%
14.0%
HFRS-2
5.13
76.8
79.5%
61.8%
53.9%
72.3%
10.5%
3.4%
HFRS-2P
5.228
66.8
86.4%
83.0%
80.7%
78.4%
59.7%
35.0%

7. Emulsion Specification Table - Elastomeric
PMREa
Grade
Min
Max
Tests on residue from distillationd:
   Penetration, 4°C (39°F), 200 g, 60 s, 0.1 mm 40
Or G* at 4°C 10 rad/s, 1% strain at
TBD
Elastic Recovery, 25C T301
50?
   OR MSCR Percent Recovery at 0.1 kPa, 52°C (50°F), % 20 —
   Ash Content, % 1
   Viscosity, 60°C (140°F), Pa∙S
500
Or Jnr at 52°C
4.5??
D Residue preparation for testing may use the alternate methods, R 78, ASTM D7403, or ASTM D7944, so as not to negatively affect the properties of any polymer modifiers contained therein

8. Motivation for Changes
Allow “Old” and “New” Test Methods
Old: Penetration, viscosity, elastic recovery
New: All DSR based
Why? – Testing Time and Effort
All residue approval tests could be conducted on one machine.
Use of moisture balance significantly reduces time.

9. Next Steps All scrub seal emulsions Elastomeric Systems
Evaluate demulsibility requirements. Considering removing from specification or a very high maximum (i.e. 80%)
Elastomeric Systems
Distribute data table and solicit test results using “Old” and “New” approaches.
Non-elastomeric Systems
Evaluate NCHRP 9-50 approach for polymer identification.