VARIATIONS IN ASPHALT ADHESION AS A FUNCTION OF AGGREGATE TYPE

Transcription

1 VARIATIONS IN ASPHALT ADHESION AS A FUNCTION OF AGGREGATE TYPE Shin-Che Huang, Raymond E. Robertson, and Troy A. Pauli 2005 Pavement Performance Prediction Symposium Adhesion and Cohesion in Asphalt Pavement June 22-24, 2005, Cheyenne, Wyoming

2 ACKNOWLEDGEMENTS The authors gratefully acknowledge the Federal Highway Administration, U.S. Department of Transportation, for financial support of this project under contract no. DTFH61-99C Dr. J. Claine Petersen, Mr. James Beiswenger, and Tony Munari.

3 SUPERPAVE PARAMETERS G * sinδ G *sinδ G * 1 [1 ] tanδ sinδ G * (sinδ ) 9 m value S value ZeroShearVis cosity

4 Adsorbed Polar Components, % PROPOSED MECHANISM MAP FOR ASPHALT-FILLER INTERACTION Incompatible AAY-1 AAM-1 Compatible Tan δ of Mastic at 10 rad/s.

5 LITERATURE Marades, E.J. and A. de Waele British Society of Rheology in London, 1949 Mack, C. Ind. and Eng. Chemistry, Vol. 49, 1957 Fink, D.F. and R.L. Griffin ASTM STP 309, 1961 Marek, C.R. and M. Herrin AAPT, Vol. 37, 1968 Bikerman, J.J. Journal of Materials, Vol. 1, 1966 Anderson, D. Thesis, 1971 Scholz, T.V. and S.F. Brown AAPT, Vol. 65, 1996 Gastmans, Andre C. 33 rd PARC, 1996 Huang, S-C., et al. TRB 1638, 1998

6 Viscosity, poise 1e+9 1e+8 1e+7 1e+6 EFFECT OF SIZE OF CALCITE ON ASPHALT 25 C (Anderson, 1971) Neat Asphalt 2.5 to 5 µm 10 to 20 µm 1e Frequency, rad/sec.

7 Viscosity, poise 1e+9 1e+8 1e+7 1e+6 EFFECT OF CALCITE ON TWO DIFFERENT 25 C (Anderson, 1971) Neat B3056 B3056/10-20µm Calcite Neat B3603 B3603/10-20 µm Calcite 1e Frequency, rad/sec.

8 2.0e+5 EFFECT OF ASPHALT SOURCES ON LIMESTONE SURFACE Viscosity, Pa s 1.5e+5 1.0e+5 5.0e+4 AAG-1 (California Valley) AAD-1 (California Coastal) Shear Rate, s -1

9 EFFECT OF FILM THICKNESS ON DIFFERENT MATERIALS, AAD-1 1.2e+5 Viscosity at 0.05 s -1, Pa s 1.0e+5 8.0e+4 6.0e+4 4.0e+4 Limestone Plate Glass Plate 2.0e Film Thickness, micron

10 INFLUENCE OF FILM THICKNESS ON TENSILE STRENGTH Marek & Herrin, AAPT 1968

11 Superpave Mixture Design Filler = 0.6 ~ 1.6 Asphalt Volumetric properties (Air void, VMA...) DOES NOT TAKE INTO ACCOUNT THE PHYSICO - CHEMICAL INTERACTIONS BETWEEN ASPHALTS AND FILLERS

12 IR SPECTRAL RESULTS OF AAG-1 WITH LIMESTONE PLATES Asphaltenes Polars Adsorbed on Aggregate Intensity Wave Number, cm

13 IR SPECTRAL RESULTS OF AAD-1 WITH LIMESTONE PLATES Asphaltenes Polars Adsorbed on Aggregate Intensity Wave Number, cm -1

14 IR SPECTRAL RESULTS OF AAK-1 WITH LIMESTONE PLATES Asphaltenes Polars Adsorbed on Aggregate Intensity Wave Number, cm -1

15 HYPOTHESIS The physical properties of thin asphalt films on mineral aggregates are not completely predictable from experiments using thick (1.0 mm) films on steel surfaces, which is the methodology employed in the current Superpave rheological specifications.

16 OBJECTIVE To develop a simple method that enables the interactions between thin asphalt layers and various aggregate surfaces to be measured.

17 CROSS-SECTIONAL VIEW OF FIXTURE Oven Fixture Support

18 DESIGNED FIXTURE Movable Plate Stationary Plate Movable Part of Fixture Sample Fixed Part of Fixture

19 SLIDING PLATE VISCOMETER

20 SANDWICH SPECIMEN 25 x 40 x 6.5 mm

21 SIMPLE FLUID SYSTEM Force Plate Specimen Plate Force Thickness d = = d r d d r r = Shearing Stress, dynes/cm = Viscosity, poises = Velocity of Plate Movement, cm/sec = Thickness of the Film, cm d = = Rate of Shear, sec -1 dr Movement (cm) = Time (sec) x Film Thickness (cm) 2

22 SAMPLE PREPARATION Before After

23 TYPICAL CREEP CURVE AAD-1 at 30 micron at 25C Deflection, mm Aggregate Plate Glass Plate Loading Time, second

24 SPR Viscosity, 1.0/sec, Pa s, Glass Plates 3.0e+6 2.5e+6 2.0e+6 1.5e+6 1.0e+6 5.0e COMPARISON OF VISCOSITY MEASURED AT 25 C VIS SPM = VIS DSR, R 2 =0.92 AAD-1 AAA-1 AAB-1 AAC-1 AAK-1 AAG-1 AAM-1 AAF e+4 1.0e+5 1.5e+5 2.0e+5 2.5e+5 3.0e+5 3.5e+5 DSR Viscosity at 1.0 rad/sec, Pa s

25 QUESTION? How about the aggregate surface? porosity, roughness

26 x-axis (length), µm 4 AFM ROUGHNESS PROFILE z-axis (height), µm Limestone Granite Plate 0 Glass Plate

27 z-axis (height), µm SURFACE ROUGHNESS Granite Limestone Glass x-axis (length), µm

28 QUESTION? How about the sample temperature?

29 28 TEMPERATURE VARIATIONS 26 Limestone Plate Sample Temperature, C Glass Plate Granite Plate Time in Temperature Chamber, minutes

30 1e+6 EFFECT OF AGGREGATES ON AAD-1 25 C, 20µm Apparent Viscosity, Pa s 8e+5 6e+5 4e+5 2e+5 Granite Plate Glass Plate Limestone Plate Shear Rate, s

31 1.6e+6 EFFECT OF DECANEDICARBOXYLIC ACID IN AAD-1 ON DIFFERENT 20µm Apparent Viscosity, Pa s 1.4e+6 1.2e+6 1.0e+6 8.0e+5 6.0e+5 4.0e+5 Granite Plate Glass Plate Limestone Plate 2.0e Shear Rate, s -1

32 SO WHAT! What has this to do with pavement performance?

33 3e+7 IMPACT OF WATER ON PAV-AGED AAD-1 ON GLASS 30µm Apparent Viscosity, Pa s 2e+7 1e+7 Before Water: 0.1/sec = 1.78e07 Pa s After Water: 0.1/sec = 1.37e07 Pa s After water Before Water Shear Rate, S -1

34 Moisture Damage Index (MDI) Viscosity After Moisture Damage Viscosity Before Moisture Damage 0.77

35 IMPACT OF WATER ON AAD-1/GRANITE (#325) ON GLASS 70 µm 1e+7 25 C Data Before Water Apparent Viscosity, Pa s 8e+6 6e+6 4e+6 Sample I Sample II 2e Shear Rate, s -1

36 IMPACT OF WATER ON AAD-1/GRANITE (#325) ON GLASS 70 µm 1e+7 25 C Data After Water Apparent Viscosity, Pa s 8e+6 6e+6 4e+6 2e+6 Sample I Sample II Shear Rate, S -1

37 IMPACT OF WATER ON AAD-1/GRANITE (#325) ON GLASS 70 µm Moisture Damage 0.1 sec-1 = 0.68

38 IMPACT OF WATER ON AAD-1/LIMESTONE (#325) ON GLASS 70 µm 1e+7 25 C Data 0.1 s -1 = 0.76 Apparent Viscosity, Pa s 8e+6 6e+6 4e+6 2e+6 After Water Before Water

39 Apparent Viscosity, Pa s IMPACT OF WATER ON AAD-1/ HYDRATED LIME ON GLASS 70 µm 1e+7 8e+6 6e+6 4e+6 2e+6 25 C Data Before Water After Water 0.1 sec -1 = Shear Rate, s

40 CONCLUSIONS Polar asphalt components interacting with a mineral substrate induce multimolecular structuring in thin films producing an increase in viscosity. Interactions of asphalts with mineral surfaces have dramatic effects on thin-film viscosities. The interactions depend on asphalt composition and aggregate surface composition.

41 CONCLUSIONS The effects of aggregate surface-induced structuring on the rheological properties of asphalt binders in the thin film region at the asphalt-aggregate interface can be measured by the specially designed fixture. It appears that the specially designed fixture can also be employed to evaluate the effect of water on the rheological properties of thin films of asphalt.

42 QUESTIONS? Thank You