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

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

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

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

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

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%

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

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.

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.