1. Overview Understanding the Performance of Modified Asphalts in Mixtures NCHRP 90-07, TPF 5(019) Thomas Harman Asphalt Pavement Team Leader, R&D Federal Highway Administration www.TFHRC.gov A A S H T O F H W A I N D U S T R Y SUPERPAVE 2005

2. 3 Projects – Common Goals Understanding the Performance of Modified Asphalts in Mixtures Lab Study NCHRP 90-07 ALF Study TPF-5(019) CRM ALF Study SPR 2(174)

3. Products Full-scale validation of... Full-scale validation of... Superpave II Superpave II – Binder specification refinements – Superpave performance test AASHTO 2002 AASHTO 2002 Applicability of the guide to recycled materials Applicability of the guide to recycled materials Other Innovations Other Innovations –FWD/Geogauge

4. Partnerships National Partners National Partners State Pooled Fund Participants State Pooled Fund Participants Industry Partners Industry Partners Collaborative Research Partners Collaborative Research Partners

5. NCHRP 90-07 AASHTO Resolution AASHTO Resolution TRB Superpave ® Committee TRB Superpave ® Committee –Binder Expert Task Group (ETG) –Mixture/Aggregate ETG NCHRP NCHRP Lab Study NCHRP 90-07

6. TRB Superpave ® Committee Recommendation

7. 17 State Pooled Fund Participants 17 State Pooled Fund Participants Not Yet TPF 5(019) SPR 2(174) ALF Studies TPF 5(019) SPR 2(174)

8. Bit Mat Mathy Construction Hot Mix Industries FNF Construction Consulpav Rubber Producers Assoc. ISS RTG Asphalt Institute NAPA / NCAT 21+ Industry Partners CitgoCitgo DowDow DupontDupont KochKoch ParamountParamount TexParTexPar Trifinary, GCATrifinary, GCA TrumbleTrumble Wright AsphaltWright Asphalt Martin Color FiMartin Color Fi

9. Collaborative Research Partners Asphalt Institute Asphalt Institute National Center for Asphalt Technology National Center for Asphalt Technology Western Research Institute Western Research Institute University of Arkansas University of Arkansas Ohio University Ohio University Queens University Queens University Arizona State University Arizona State University FWD Users Group FWD Users Group

10. Output – Validation/Calibration Data, Specification Recommendations Relationships TRB Superpave Committee -Binder ETG -Mix/Aggregate ETG TPF 5(019) / SPR 2(174) Technical Working Group TWG Laboratory Study 90-07 ALF Loading Response Data Collaborative Researchers Industry Support

11. Superpave ® 2002 Asphalt Binder Implementation Status Asphalt Binder Implementation Status Implemented In Progress Undetermined Implemented In Progress Undetermined

12. Superpave ® Plus Elastic recovery Elastic recovery Forced ductility Forced ductility Toughness and tenacity Toughness and tenacity Phase angle Phase angle Method (mode and dose) Method (mode and dose) Combinations Combinations 0 10 20 30 40 50 As isModified PG Grade Specifications Number of States 14

13. ’93 SHRP Binder Study Conducting by FHWA Surface Mix: 19mm AC-05PG 59 AC-10PG 65 AC-20PG 70 Styrelf (SBR)PG 88 Novophalt (PE)PG 77 Base Mix: 37.5mm AC-05 AC-20

14. Key Findings FHWA

15. ALF vs SST ( є P5000 )

16. New Asphalt Binders NCHRP 90-07

17. Target Grade: PG 74-29 Grade dictated by air blown binder Grade dictated by air blown binder High temperature within ±1º C High temperature within ±1º C Low temperature within ± 2º C Low temperature within ± 2º C –Based on critical cracking temperature (BBR and DT)

18. Aggregates Diabase from Leesburg, Virginia (used in previous ALF validation study) Diabase from Leesburg, Virginia (used in previous ALF validation study) Limestone from Fredrick, Maryland (used in SHRP-- aggregate RC, and by 9-19 contractor) Limestone from Fredrick, Maryland (used in SHRP-- aggregate RC, and by 9-19 contractor)

19. Binder and Modifier Suppliers… Citgo:High Temp (PG 70-25) Base (PG 66-28) Flux (PG 55-32) Citgo:High Temp (PG 70-25) Base (PG 66-28) Flux (PG 55-32) Trumbull:Air Blown (PG 73-28) Trumbull:Air Blown (PG 73-28) Dupont:ETP - Dupont:ETP - Elastomeric-terpolymer TFHRC:CMCRA Color-fi-CMCRA TFHRC:CMCRA Color-fi-CMCRA

20. Binder and Modifier Suppliers Texpar:Grafted SBS (l+br) Grafted EVA Texpar:Grafted SBS (l+br) Grafted EVA –Shell 1184:SBS radial –Dexco 2518:SBS linear –PolybuiltEVA Dow Chemical:ESI (ethylene-styrene inter-polymer) Dow Chemical:ESI (ethylene-styrene inter-polymer)

21. Asphalt Binders (Phase I) Crude Modification SourceModeMethodDose (%)PG Grade VBBNeat--67-28 VBBNeat--71-28 VBBAB--74-28 VBBETP-2.276-31 VBBSBSLG3.7572-33 VBBSBSL3.7572-31 VBBSBSRG3.2571-32 VBBEVA-5.570-31 VBBEVAG5.573-31 VBBESI-5.076-32 VBBCMCRA-5.076-29

22. Asphalt Binders (Phase II) Increasing Range of Modified Asphalt Binders Phase I Phase II

23. Laboratory Testing

24. Similar binder properties do not ensure similar mix properties. Similar binder properties do not ensure similar mix properties. To Date FINDINGS

25. Lab Binder & Mastic (NCHRP 90-09) Characterization... Aging Methods Aging Methods High Temperature High Temperature –G*, δ –SSV, ZSV –Repeated Creep –Calculated Parameters Chemical Analysis (WRI) Chemical Analysis (WRI) Fibers (Queens U) Fibers (Queens U) Screening: LAST / PAT Screening: LAST / PAT Intermediate Intermediate –G*, δ –Fatigue Low-Temperature Low-Temperature –BBR –BBR + DT (TSAR) –DT Only –Asphalt Binder Cracking (ABC) Device Moisture: Moisture: –Pneumatic Adhesion

26. Zero-Shear Viscosity (ZSV) a b c Log (Viscosity) Log(Shear Rate) or Stress 00

27. 0 50 100 150 200 250 300 350 400 450 Air_Blown ETP ESI EVA EVA_GRAF PG70-22 SBSLinGraf SBSLinear SBS_RAD_GRAF ZSV at 70oC ZSV - Full Master Curve ZSV - Single Freq Swp PG75-29 PG78-32 PG77-31 PG75-31 PG76-32 PG71-29 PG72-33 PG70-31 PG72-32

28. Mixture Tests… Stiffness:SST Frequency Sweep Dynamic Modulus, /E*/ Stiffness:SST Frequency Sweep Dynamic Modulus, /E*/ Rutting:SST Repeated Shear Asphalt Pavement Analyzer Pine Rotary Wheel Tester Simple Performance Tests Rutting:SST Repeated Shear Asphalt Pavement Analyzer Pine Rotary Wheel Tester Simple Performance Tests Rutting and Moisture Sensitivity: Hamburg Wheel-Tracker Rutting and Moisture Sensitivity: Hamburg Wheel-Tracker

29. Mixture Tests Fatigue Cracking: Fatigue Cracking: SHRP Bending Beam Test Simple Performance Tests Low-Temperature Cracking: Indirect Tensile Creep Low-Temperature Cracking: Indirect Tensile Creep TSRST TSRST

30. MATERIALS AVAILABLE Plant produced mixtures taken from trucksPlant produced mixtures taken from trucks Stockpiled materials - Can a standard mixture be used in lab studies?Stockpiled materials - Can a standard mixture be used in lab studies? Single gradation? Single gradation? Single binder content? Single binder content? Should there be a single binder content for all mixtures? Should there be a single binder content for all mixtures? Pavement samplesPavement samples

31. MIXTURE CHARACTERISTICS (MOST MIXTURES)  High-temp PG from 72 to 74  Single aggregate gradation  % AC for plant mixtures is 5.1 to 5.5%  % AC for lab batched mixtures is 5.4%  7% air voids

32. MIXTURE CHARACTERISTICS (EXCEPTIONS) Crumb rubber mixture in lane 1Crumb rubber mixture in lane 1 Asphalt content is 7.0%Asphalt content is 7.0% Open aggregate gradation and higher VMAOpen aggregate gradation and higher VMA PG cannot be measuredPG cannot be measured Terminal blend has high-temp PG of 81Terminal blend has high-temp PG of 81 PG of the asphalt with fiber cannot be measuredPG of the asphalt with fiber cannot be measured

33. TESTS COMPLETED TO DATE Plant-Produced MixturesPlant-Produced Mixtures French PRT at 74°CFrench PRT at 74°C Trial Hamburg WTD tests at 58°CTrial Hamburg WTD tests at 58°C Hamburg WTD at 64°CHamburg WTD at 64°C SST at 74°CSST at 74°C Trial Simple Performance Tests at 74°CTrial Simple Performance Tests at 74°C Lab Batched MixturesLab Batched Mixtures French PRT at 74°CFrench PRT at 74°C

34. Lane Material Rut Depth, mm 5CR-TB 6.9 3Air Blown 8.0 10Air Blown 8.2 2PG 70-22 9.2 11SBS LG 11.7 8 PG 70-22 11.8 4SBS LG 13.6 1 CR-AZ on PG 70-22 14.3 7Fiber 15.1 12ETP >20.0 9SBS 70-40 >20.0 6ETP >20.0 FRENCH PRT RESULTS FRENCH PRT RESULTS PLANT-PRODUCED MIXTURES

35. French PRT Lane Material Rut Depth, mm 2PG 70-22 9.2 8PG 70-22 11.8 Sig** 3Air Blown 8.0 10Air Blown 8.2 NS 4SBS LG 13.6 11SBS LG 11.7 NS 6ETP >20.0 12ETP >20.0 NS **Could be due the difference in % AC (5.1 vs. 5.4) RUT DEPTHS FOR LANES WITH THE SAME MIX

36. Lab Material PlantBatched CR-TB 6.9 6.0 Air Blown 8.1 7.8 PG 70-22 10.3 15.8 SBS LG 12.6 12.3 CR-AZ on PG 70-22 14.3 (To Be Tested) Fiber 15.1 7.8** SBS 70-40>20.0 >20.0 ETP>20.0 17.0 **Do not know if the dispersion of the fibers is the same RUT DEPTHS BY TYPE OF SAMPLE

37. CONCLUSION FROM FRENCH PRT No correlation to PG.No correlation to PG. Large range in rut depths compared to the range in PGLarge range in rut depths compared to the range in PG

38. Rut Depth Lane Material at 58 C, mm 5CR-TB 4.0 10Air Blown 2.9 12ETP 7.2 Conclusions: All three mixtures passed the test Range in rut depth is low Increase the test temperature from 58 C to 64 C HAMBURG WTD TRIAL TESTS HAMBURG WTD TRIAL TESTS PLANT-PRODUCED MIXTURES

39. Hamburg WTD at 64 C Lane Material WP at a 10-mm Rut Depth 5CR-TB 12800 3Air Blown 16100 10Air Blown 2PG 70-22 11SBS LG 10300 8 PG 70-22 8500 4SBS LG 7800 1 CR-AZ on PG 70-22 7Fiber 7900 12ETP 9SBS 70-40 6ETP 11600 PLANT-PRODUCED MIXTURES

40. Lane Material French Hamburg** 5CR-TB 1 2 3Air Blown 2 1 10Air Blown 3 2PG 70-22 4 11SBS LG 5 4 8 PG 70-22 6 5 4SBS LG 7 7 1 CR-AZ on PG 70-22 8 7Fiber 9 6 12ETP10 9SBS 70-40 10 6ETP10 3 **Tests are still being performed RANKINGS BASED ON THE AVERAGES

41. CONCLUSIONS FROM HAMBURG WTD All three mixtures tested at 58 C passed.All three mixtures tested at 58 C passed. All seven mixtures tested at 64 C failed.All seven mixtures tested at 64 C failed. Large range in performance compared to the range in high temp PG.Large range in performance compared to the range in high temp PG. The elastomeric terpolymer (ETP) performed better in the Hamburg WTD than in the French PRT.The elastomeric terpolymer (ETP) performed better in the Hamburg WTD than in the French PRT.

42. Laboratory Low-Temperature Study BBR BBR BBR + DT (TSAR) BBR + DT (TSAR) DT Only DT Only Asphalt Binder Cracking (ABC) Device Asphalt Binder Cracking (ABC) Device IDT IDT TSRST TSRST Hollow Cylinder Hollow Cylinder

43. Construction A A S H T O F H W A I N D U S T R Y SUPERPAVE 2005

44. Final Test Matrix CRMA 70-22 1 2 AB 3 SBS 4 TB CR 5 Elvo 6 70-22 + Fibers 7 70-22 8 SBS 64-40 9 AB 10 SBS 11 Elvo 12

45. FWD Results

49. Lane(s) Binder Designation Base Binder PG Binder Pre- Construction PG Binder As- Constructed 1CR-AZCitgo(Base 60-28)N.A. 2 and 8PG 70-22Citgo73-23 3 and 10Air BlownCitgo75-2874-28 4 and 11SBS lgTexPar71-2974-28 5CR-TBWright Asphalt 77-2879-28 6 and 12ElvaloyCitgo76-3074-31 7Polyester Fiber Citgo73-23 9SBS 64-40Koch64-4071-38 Binder PG Grade

50. General Sections CR-AZ (Lane 1) Fiber+Control (Lane 7) Binder Content (%) 5.3  0.27.1  0.25.3  0.2 Aggregate Gradation Gradation AGradation BGradation A Lime1 % Fiber NA 0.2-0.3 %

51. FP - 96 Acceptance Sampling & Testing Frequency ALFTestLanes Asphalt Content T 308 Gradation T 30 Rice, G mm T 209 Volumetric Properties: Va, VMA, VFA PP 28

52. FP - 96 Acceptance Sampling & Testing Frequency Control Strip (Parking Lot) Asphalt Content T 308 T 287 Gradation T 30 Rice, G mm T 209 Volumetric Properties: Va, VMA, VFA PP 28

53. 90-01 Mobile Lab Variability of Lime in TFHRC aggregate bins Variability of Lime in TFHRC aggregate bins Ignition Furnace Calibrations Ignition Furnace Calibrations –Correction Factors influenced by hydrated lime Nuclear Gauge Calibrations Nuclear Gauge Calibrations –Calibrations influenced by hydrated lime

54. Sensitivity Study by 90-01

58. In-Place Air Voids (%) Based on Cores

59. Binder Content (%)

60. Lessons for PTF Using control strips (parking lot) was key Using control strips (parking lot) was key Proper distribution of fiber and lime in mixes is difficult Proper distribution of fiber and lime in mixes is difficult Material Transfer Device has advantages and disadvantages Material Transfer Device has advantages and disadvantages

61. Proposed ALF Loading Plan A A S H T O F H W A I N D U S T R Y SUPERPAVE 2005

62. Site 2 TBD Site 4 Fatigue T2 Site 1 Rutting Test Site 3 Fatigue T1 Typical Test Layout for a Lane

63. Proposed Loading Conditions FailureModePavementTemperatureWheelLoadLateralWander Rutting 58 – 76 o C ? 10 kip No Fatigue 19 o C 12 – 16 kip ? Yes 28 o C 12 – 16 kip ? Yes

65. 10 % Deformation 30,000 Passes

66. 8 % Deformation 30,000 Passes

67. 12 34 Rutting T high = 64°C Fatigue T int = 19°C Fatigue T int = 28°C Replicate Products – Raw Data

68. Analysis Goal

69. Data All data will be available (computerized) for anyone who wants to analyze it All data will be available (computerized) for anyone who wants to analyze it

70. Reporting Understanding the Performance of Modified Binders in Asphalt Mixes: Understanding the Performance of Modified Binders in Asphalt Mixes: –Currently have 10 draft reports FHWA NCHRP IN COOPERATION WITH: National Cooperative Highway Research Program Transportation Research Board National Research Council

71. Products Full-scale validation of... Full-scale validation of... Superpave Superpave – Binder specification refinements – Superpave performance test AASHTO 2002 AASHTO 2002 Applicability of the guide to recycled materials Applicability of the guide to recycled materials FWD/Geogauge FWD/Geogauge

72. “So what?” A A S H T O F H W A I N D U S T R Y SUPERPAVE 2005

73. Superpave ® II PG based on Degree Days

74. Output – Validation/Calibration Data, Specification Recommendations Key: Communication TRB Superpave Committee -Binder ETG -Mix/Aggregate ETG TPF 5(019) Technical Working Group TWG Collaborative Researchers Laboratory Study 90-07 ALF Loading Response Data Industry Support

75. Technical Working Group (TWG) Meeting December 5-6, 2002