1. Mn/DOT Shingle Study By Jim McGraw HMA Shingle Workshop July 12, 2006

2. Shingle Study Objectives  Variability of Shingles  Effect on Mix & Binder  Deleterious Material

3. Study Mix Design

4. Material Variability  10 Random Samples  % Binder  PG Grading  Extracted Gradation  Deleterious Material Paper/Glass Fiber Procedures  Mixture Testing

5. Material Variability- Binder  RAP Average 7.0 % S.D. 0.2 %  Tear-Off Average 36.4% S.D 1.9 %  Manufacture Waste Average 19.6 % S.D. 2.3 %  5% Addition-Binder 1.0% MW, 1.8% TO TO Stiffer

6. Extracted Gradation  Tear Off finer on sieves less than #10  Additional Processing to remove metal  TO mixes less -#100 & #200

7. Extracted Gradation

8. Effect of Hot Mix Plant  Unexpected RTFO Losses  TO- Average 1.30%, S.D.0.4%  MW- Average 0.80 S.D. 0.4%  RAP-Average 0.7% S.D. 0.1%  Binder – 0.3-0.7%

9. Shingle HT PG Grade  MW- Average 141.7 S.D. 6.1  TO-Average 126.0 S.D. 4.5  RAP- Average 76.1 S.D. 0.9

10. Mix HT PG Grade  TO- Avg 73.2 S.D. 0.2  MW-Avg 70.9 S.D. 0.4  RAP-Avg 64.2 S.D. 0.3  MW- Full grade stiffer  TO- 1 ½ grade stiffer  RAP Grade - soft

11. Shingles LT PG  TO- Avg 1.1 S.D. 5.1  MW- Avg –11.0 S.D. 1.9  RAP- Avg –25.8 S.D. 0.7

12. Mix LT PG  TO- Avg –28.8 S.D. 2.4  MW- Avg –26.2 S.D. 0.2  RAP- Avg –29.2 S.D. 0.9  PG 58-28- PG 60-30  Good low temp from RAP  % Mixing ???

13. Deleterious Materials  MW- Average 1.74% glass fibers with S.D of 1.15 Average of 1.34 % paper and a S.D of 0.48  Tear Off- Average 0.66 % glass fibers with S.D of 0.17 Average of 16.96 % paper and a S.D of 2.12  AASHTO Spec- 0.5%

14. Shingle Blending Chart

15. TH 10 Shingle HMA- SP 0502-09  PG 64-28/30% RAP - PG 69.5-29.8  PG 64-28 /27% RAP and 3 % shingles PG 72.5-25.0  PG 64-28/5% shingles/25% RAP- PG 75.8- 25.5  Adding 3% shingles it increases stiffness on both ends by ½ grade over that of the 30% RAP.  Adding an additional 2% for a total of 5% increases the high end by an additional ½ grade but doesn't effect the low temp grade  Some cracking seen

16. Conclusions  More mixture testing with true control Mix Fatigue Test Verify binder grade  Shingle Only Study Softer Binder  Field Review  Revisit present spec