CANADIAN USER PRODUCER GROUP FOR ASPHALT 2010 RECYCLED ASPHALT PAVEMENT

Transcription

1 CANADIAN USER PRODUCER GROUP FOR ASPHALT 2010 RECYCLED ASPHALT PAVEMENT The Latest Rap on RAP Gerry Huber Heritage Research Group Chairman RAP and Shingle ETG

2 RAP Expert Task Group Formed 2007 Members DoTs Industry Academia

3 Purpose of ETG National Guidance Coordinate Develop Improve Recommendations Correct use of technology State of practice

4 Main Issues Identified Performance Test Best Practices Manual Binder Grade Changes Field Performance Variability

5 Performance Studies of Asphalt Pavements with Greater than 25% RAP Randy C. West, NCAT October 7,

6 Barriers to Increasing RAP 6

7 A Performance Comparison of RAP vs. Virgin Mixes LTPP SPS-5 pavement sections 18 U.S. states and Canadian provinces At least 30% RAP used in recycled mixes Projects range in age from 6 to 17 yrs 7

8 General Performance Percentage of Sections Below General Pavement Performance Thresholds Distress Parameter Threshold RAP Sections Virgin Sections IRI 2.0 m/km 86% 89% Rutting 10 mm 71% 78% Fatigue Cracking 25% of WP area 60% 72% Longitudinal Cracking 25% of section length 79% 86% Transverse Cracking 20 cracks per section 47% 64% Block Cracking 10% of section area 89% 94% Raveling 10% of section area 8 75% 69%

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15 High RAP Performance in Florida Jim Musselman Florida Department of Transportation

16 Statewide Pavement Performance Deficient Pavements (%) Criteria Ride Crack Rut Section of Florida Statutes: Ensuring that 80% of the pavement on the SHS meets Department Standards

17 D.R.I.P Data Rich. Information Poor

18 Pavement Management Data

19 Age (yrs) 18 Only Projects >5,000 tons (No consideration for traffic) % 30 % 35 % 40 % 45 % 50 % 0 Percent RAP (%)

20 RAP Management Best Practices RAP Needs Analysis Milling for Success Multiple-source RAP piles Crushing Considerations Screening Options Best Practices for Stockpiling Sampling and Testing of RAP Stockpiles Production of Recycled Asphalt Mixes 20

21 Barriers to Increasing RAP 21

22 Milled RAP Keep millings from different projects in separate stockpiles. Milled RAP can typically be used as is in HMA without further

23 Multiple Source RAP Stockpiles It is vital to prevent dumping of any deleterious materials in the pile from the beginning. Clearly instruct all truck drivers hauling materials to the yard where to dump different types of materials

24 RAP Crushing Process Small dozer to break up RAP and push it to a loader Mix up the material while feeding it into the Processing Unit

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26 Fractionating RAP The practice should not be mandated; it should be the contractor s business decision if and when to fractionate RAP. 26

27 Variability: RAP vs. Aggregate Based on 74 RAP stockpiles in 14 states, and 60 Aggregate stockpiles in 6 states 27

28 Fractionated vs. Unfractionated 28

29 Investigation of Low and High Temperature Properties of Plant-Produced RAP Mixtures Becky McDaniel RAP ETG December 17, 2009

30 Experimental Design Reclaimed Asphalt Pavement Asphalt Binder Grade PG PG % 15% 25% 40% X X X X Mix A Mix B Mix C Mix D X X Mix E Mix F

31 Example Binder Data ID Grade HT Grade (DSR) LT Grade (BBR) True Grade T crit (TSAR) Virgin PG Binders PG A B PG C D E PG F

32 Log E*, MPa One Example - Mix E* PG MixA (0%0 RAP) MixB (15% RAP) MixC (25% RAP) MixD (40% RAP) E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 Log Reduced Frequency, Hz

33 Log E*, MPa One Example - Mix E* Control versus PG MixA (0% RAP) MixE (25% RAP) MixF (40% RAP) E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 Log Reduced Frequency, Hz

34 Log E*, MPa One Example - Mix E* PG64-22 versus PG MixC (25% RAP) MixE (25% RAP) MixD (40% RAP) MixF (40% RAP) E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 Log Reduced Frequency, Hz

35 E*, MPa Second Example - Mix E* Control versus PG Mix 5A (0% RAP) Mix 5E (25% RAP) Mix 5F (40% RAP) E-04 1.E-02 1.E+00 1.E+02 1.E+04 1.E+06 Reduced Frequency, Hz

36 Strength, kpa IDT Strength Example Strength Temperature Pvmt. Cracking Temperature, C 2500 PB-A PB-B PB-C PB-D PB-E PB-F -28 Mixes

37 Stiffness, GPa IDT Stiffness Example Stiffness Temperature Pvmt. Cracking Temperature, C 10 PB-A PB-B PB-C PB-D PB-E PB-F -28 Mixes

38 Strength, kpa IDT Strength Example Strength Pvmt. Cracking Temperature, C Temperature 2000 JH-A JH-B JH-C JH-D JH-E JH-F -28 Mixes

39 Strength, kpa IDT Strength Example Strength -16 Pvmt. Cracking Temperature, C Temperature 3000 EB-A EB-B EB-C EB-D EB-E EB-F -22 Mixes

40 Stiffness, GPa IDT Stiffness Example Stiffness 30 Temperature -16 Pvmt. Cracking Temperature, C 20 EB-A EB-B EB-C EB-D EB-E EB-F -22 Mixes

41 General Conclusions Low Temperature Cracking (IDT) Slight effects on critical cracking temp at up to 25% RAP with PG64-22 Critical cracking temp of 40% RAP with PG64-22 was slightly warmer but still around -22 C

42 Current ETG Activities Best Practices document by TRB 2011 Research Needs statements Performance Prediction tests Shingles Recommend changes to R35 Superpave Volumetric Design Change to % Binder Replacement

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