1. ETF Rejuvenator Task Force
June 2019 Update
Hassan Tabatabaee, Cargill

2. Task Force Members
Hassan Tabatabaee, Cargill (Chair)
Andrew Hanz, MTE
Andy Clayton, Blue Line
Larry Galehouse, MSU
Pete Montenegro, Collaborative Aggregates (replacing Katy Fleury)
Russell Milan, MI Paving
Gayle King, GHK
Colin Durante, Pavement Technology
2 Conference Calls have been held to discuss TF scope and objectives.

3. Task Force Objectives Education: Specification:
Offer educational material to ETF and industry on past and current state of the practice for rejuvenators in pavement preservation.
Joint presentation by Andy Calyton, Hassan Tabatabaee, and Andrew Hanz, hopefully during next ETF meeting.
Specification:
Address gaps in pavement preservation specifications with regards to rejuvenators.
Utilize and build on existing and historical state agency and industry specifications
Align activities with other parallel rejuvenator committees (e.g. ASTM and AI).
Research Need Statements
Create RNS to address identified gaps in performance-based test methods and mechanisms for rejuvenators pavement preservation.
Build on RNS previously submitted by ETF to NCHRP.

4. Education
Joint presentation on past and current state of the practice for rejuvenators in pavement preservation, hopefully during next ETF meeting.
Andy Calyton to present on past rejuvenating pavement preservation practice history,
Hassan Tabatabaee to present on current bio-based rejuvenating practice in pavement preservation
Andrew Hanz to present on NCAT scrub seal life-extension experience.
Future presentations may be potentially organized as a webinar.

5. Specification Specification being considered so far:
California Rejuvenating Pavement Preservation Specification
ASTM D4552 (Screening spec for Hot Mix rejuvenators)
Rejuvenator Spec table in Scrub Seal Specification
Possible approaches being considered:
Create separate specification for each pavement preservation application that contains its own embedded rejuvenator specification table (as in the current proposed Scrub Seal spec)
Create a basic stand-alone specification for pavement preservation rejuvenators that can be referenced by other pavement preservation standard methods.
In either case, performance-based test methods for rejuvenating pavement preservation application are a current gap in knowledge.

6. Research Need Statements
Three general sets of ideas have been proposed by the task force so far. Scope will be narrowed as work begins on the documents:
Scrub seal performance test (includes measuring diffusivity of rejuvenators in underlying layers.)
Rejuvenating fog performance test (includes measuring diffusivity of rejuvenators in underlying layers.)
Emulsion and bitumen quality/analytical assessment after introduction of rejuvenators,– e.g. chemical, stability, rheology, etc. (Potentially expanding research to include emulsion residue modification and softening with additives)