Evaluation of Asphalt Shingle Binder Availability Factor Gerald

Evaluation of Asphalt Shingle Binder Availability Factor Gerald Huber November 8, 2013

Asphalt Binder Availability? • The asphalt binder in shingles is very hard. • All of it can not act like asphalt. • How much of it should I discount? • The remainder is available.

“It’s All In There” • All of the asphalt binder is in the mix. • Homogeneous? – Finer is better – Warm Mix : Hot Mix

Asphalt Binder Availability • AASHTO PP 53, Section 6 • Volumetric design w/o shingles – Design virgin asphalt content 5. 8% • Add Shingles to design – Asphalt content increases 6. 9% 5. 45% virgin 1. 55% RAS

Calculate Contribution Virgin Asphalt no Shingles Initial Estimate Contribution Virgin Asphalt with Shingles Percent of Shingles Asphalt Content of Shingles

Calculate Contribution 5. 8% 28% 5. 45% 5. 0% 30. 6%

Possible Results • Section 6. 2 – Virgin asphalt decreases • Some of the shingle binder is available – Virgin asphalt decreases exactly the amount in the shingles • All of the shingle binder is available – Virgin asphalt increases • More asphalt required to coat the shingles than is contained in the shingles

Final Estimate of Asphalt Binder Availability • Section 6. 2. 6 – True availability factor is always greater than the estimated value. – True value defined calculated by Equation 2 28% 64%

Back to Basics • 15. 5% Virgin • 17. 5% Shingles Added

Study Hypothesis • “Asphalt Binder Availability” – Related to change in VMA • Mineral Matter in shingle increases VMA – Properties of asphalt binder not related to increase in VMA

Experiment • Design mixture with no shingles • Add shingles (with full asphalt content) – Calculate VMA and air voids • Add shingles (with half normal asphalt content) – Calculate VMA and air voids • Add shingles (with no asphalt content) – Calculate VMA and air voids

Shingles Used • Tear Off Shingles – Indianapolis, Indiana • Tear Off Shingles – Stockton, California • Manufacture Waste – Chicago, Illinois

Properties of Shingles in Study Source Maximum Specific Gravity, Gmm Average Asphalt Content, % Effective Specific Gravity of the Aggregate, Gse Chicago MW 2. 204 19. 0 2. 615 Indianapolis TOS 1. 908 23. 2 2. 573 Stockton TOS 1. 779 30. 6 2. 619

12. 5 mm 9. 5 mm 4. 75 mm 2. 36 mm 1. 18 mm 0. 600 mm 0. 300 mm 0. 150 mm 0. 075 mm 100. 0 97. 8 70. 5 41. 0 26. 2 17. 5 10. 9 6. 6 4. 9 % AC Absptn Actual VMA Actual Voids 5. 80 0. 92 15. 5 4. 0 Virgin Design • 9. 5 -mm Nominal Maximum Size • PG 64 -22

Materials • • • Crushed Stone Sand Natural Sand Baghouse Fines PG 64 -22 Post Consumer Shingles

Crushed Stone

Stone Sand

Natural Sand

Baghouse Fines

Indianapolis Shingles

Extracting Shingles

Extracted Shingles - #4

Extracted Shingles - #30

Extracted Shingles - #100

Extracted Shingles - #200

Design with Stockton Shingles Mix Design Material Blend Virgin Blend 100% Extracted 50% Extracted RAS RAS % AC Virgin 5. 8 5. 0 4. 3 % RAS AC 0. 0 0. 8 1. 5 % AC, Total 5. 8 VMA, % 15. 5 17. 4 17. 3 17. 5 Air Voids, % 4. 0 7. 0 6. 8

Stockton Shingle Designs, VMA 18. 0 17. 0 16. 0 15. 0 14. 0 13. 0 12. 0 11. 0 10. 0 Virgin RAS Non Extracted RAS 50% Extracted RAS 100% Extracted

Indianapolis Shingle Designs, VMA 18. 0 17. 0 16. 0 15. 0 14. 0 13. 0 12. 0 11. 0 10. 0 Virgin RAS Non Extracted RAS 50% Extracted RAS 100% Extracted

Chicago Shingle Designs, VMA 19. 0 18. 0 17. 0 16. 0 15. 0 14. 0 13. 0 12. 0 11. 0 10. 0 Virgin RAS Non Extracted RAS 50% Extracted RAS 100% Extracted

Stockton Shingle Designs, %AC 8. 0 7. 0 6. 0 5. 0 4. 0 3. 0 2. 0 1. 0 0. 0 Virgin RAS Non Extracted RAS 50% Extracted RAS 100% Extracted

Indianapolis Shingle Designs, %AC 8. 0 7. 0 6. 0 5. 0 4. 0 3. 0 2. 0 1. 0 0. 0 Virgin RAS Non Extracted RAS 50% Extracted RAS 100% Extracted

Chicago Shingle Designs, %AC 8. 0 7. 0 6. 0 5. 0 4. 0 3. 0 2. 0 1. 0 0. 0 Virgin RAS Non Extracted RAS 50% Extracted RAS 100% Extracted

Stockton Asphalt Binder Availability, % 70. 0 60. 0 50. 0 40. 0 30. 0 20. 0 10. 0 Virgin RAS Non Extracted RAS 50% Extracted RAS 100% Extracted

Indianapolis Asphalt Binder Availability, % 60. 0 50. 0 40. 0 30. 0 20. 0 10. 0 Virgin RAS Non Extracted RAS 50% Extracted RAS 100% Extracted

Chicago Asphalt Binder Availability, % 0. 0 -20. 0 -40. 0 -60. 0 -80. 0 -100. 0 -120. 0 -140. 0 Virgin RAS Non Extracted RAS 50% Extracted RAS 100% Extracted

Conclusions • “Asphalt Binder Availability” not related to asphalt binder properties – Worst for manufacture waste – Dependent on %AC in the RAS • Increased %AC related to mineral matter of shingles, – Chicago manufacture waste had highest increase (most granules) • 1. 6% – Stockton and Indianapolis had lower increases • 1. 1% and 0. 8% • Asphalt Binder Availability Factor from PP 53 not applicable

Next Steps • Determine effect of shingle asphalt binder on HMA performance properties – Fatigue – Low Temperature Cracking • Set design guidelines to ensure mixture performance.

“It’s All In There” • How to account for the effects – Maximum asphalt binder ratio? – Grade of new asphalt binder? – Finer grind size?

Thanks • Gerald Huber