Wednesday March 6, 2013 Case Study: High RAP Pilot Project

Contractor Perspective: Dan Karcher, R.E. Pierson Materials

Acknowledgements R.E. Pierson Materials Arawak Paving Nustar Asphalt New Jersey Asphalt Paving Association Rowan University Rutgers University New Jersey Department of Transportation

Plant Quality Control Training on best practices for managing RAP

Consistency Plant component changes

Dillman drum and multiple RAP bins, Astec Fractionating System Addition of third liquid asphalt tank

Bridgeport Plant

Best Practices For Managing RAP Inventories

Avoid contamination Mix as you feed Don’t under-process Don’t process when it rains Blend again when moving Fractionating

Pros & Cons

Quality Control Testing Testing and analyzing of all materials Consensus properties Asphalt binder content

Ignition oven and solvent extraction Rowan University

Leave no stone unturned

Conservative Approach Competition is getting stiffer Maintain our economical edge

Superpave High RAP Mix Designs Purpose

Minimize the stress, maximize performance, and minimize maintenance cost

Four high RAP mix designs HMA 9.5M76 20% RAP (Nustar PG76-22) HMA 9.5M76 30% RAP (Nustar PG76-22) HMA 12.5M64 30% RAP (Nustar PG58-28) HMA 12.5M64 40% RAP (Nustar PG58-28) Approved for volumetrics by NJDOT Region South

Materials

Checking Volumetrics By Performance Tests

Performance Tests Asphalt Pavement Analyzer Overlay Tester

Requirements HMA 9.5M76 High RAP Surface Course

APA Rutting <4.0mm Overlay Tester Fatigue >175 cycles

HMA 12.5M64 High RAP Intermediate Course APA Rutting <7.0mm Overlay Tester Fatigue >100 cycles

Trial and Error PG Grade NMAS RAP % OT(cycles) APA Rutting 58-28 12.5mm 30% 1442 9.28mm 58-28 12.5mm 40% 503 8.56mm 76-22 9.5mm 20% 365 5.53mm 76-22 9.5mm 30% 129 4.37mm Address rutting concern

Reference NCHRP 673

Adjusting Mix Designs to Improve Rut Resistance

Increase the binder high-temperature grade If the binder is not modified, consider using a polymer-

modified binder of the same grade or one high-temperature grade lower

If the binder is polymer-modified, try a different type of modified binder

Increase the amount of mineral filler in the mix, adjusting the aggregate gradation if necessary to maintain adequate VMA

Decrease the design VMA value Replace part of the aggregate (fine, coarse, or both)

Nustar Formulated Binder 64 High RAP 1

PG 64-28 76 High RAP 1

PG 70-22 Next set of samples

Continuing Performance Testing PG Grade NMAS RAP% OT APA Rutting 64 HRAP 1 12.5 40% 80 5.94mm 76 HRAP 1 9.5 30% 121 3.66mm 64 HRAP 1 12.5 35% 560 PASS 76 HRAP 1 9.5 25% 320 PASS Passed performance testing requirements of NJDOT

HMA High RAP Specification

High RAP Mix Designs For Production

Ensure quality Produce mixes on private sector

Utilizing pre-crushed RAP Same RAP used for lab work

HMA 12.5M64 Plant Produced High RAP 6.62mm rutting 752 OT cycles

HMA 9.5M76 Plant Produced High RAP 6.02mm rutting 982 OT cycles

HMA 12.5M64 PASSED HMA 9.5M76 FAILED – Try Again Possible binder contamination – mix checked at 300 and 450 ton locations APA 2.72mm, OT cycles 169. Some passed, some failed

Ready For Job Site Plant quality assurance/quality control results

complied Plant produced mix complied with performance

requirements Field results complied for air voids and ride quality

Final Results Performance

HMA 9.5M76 25% RAP 1691 OT Cycles 3.56mm Rutting

HMA 12.5M64 35% RAP 409 OT Cycles 6.57mm Rutting

Compaction Average of HMA 9.5M76 High RAP surface course density is

6.7% air voids for two lots Average of HMA 12.5M64 High RAP surface course density is

5.6% air voids for three lots

Final Results (cont.) Inconsistencies with surface course air voids resulted

in pay disincentive Consistent results with intermediate course air voids

resulted in pay incentive Ride quality

Average IRI 54.3 – pay incentive

Time To Follow Through HMA 12.5M64 intermediate course can be used as

surface course with 35% RAP and still meet performance criteria

HMA 9.5M76 surface course with 25% RAP possible replacement of HPTO Thin Overlay Cost savings without jeopardizing performance

Balancing High RAP mix designs Better Roads – Upping the RAP article

“Quality is doing the right thing when no one is looking.” -Henry Ford