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Bitumen Chemomechanics Related to Pavement Performance
Troy Pauli, Will Grimes, Alec Cookman, Ryan Boysen, Shin-Che Huang, Mike Farrar, Mike Harnsberger, James
Beiswenger, Pam Coles and Bruce Thomas
51st Petersen Asphalt Research Conference and Pavement Performance Prediction Symposium
Innovations for Predicting Pavement PerformanceMeasurements and Models
Hilton Garden Inn & University of Wyoming Conference CenterJuly 17, 2014, Laramie, Wyoming
Acknowledgments
The authors gratefully acknowledge the Federal Highway Administration, U.S. Department of Transportation, for financial support of this project under contract no. DTFH61-07-H-00009 (ARC).
Delft University of TechnologyTom Scarpas, Sybrand van de Zwaag and Alexander Schmets
Asphalt Research Consortium Partners
Outline
• Introduction• Bitumen Composition• Asphalt Macrostructure Modeling• Bitumen Chemomechanics
• Properties of the Oil Phase • Viscous Flow• Diffusion and Molecular Mass• Thermal Fatigue
• Properties of the Maltene and Asphalt Phase• Viscous Flow• Healing
• Asphalt Macrostructure and RAP Blending• Wax Surface Freezing
• Sectorization and Rippling• Healing
• Conclusions
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Per
cent
Of F
ract
ion
Asphalt
AsphaltenesResinsWaxNeutrals
Asphalt Composition(SARA/IEC/WAX)
Asphalt Microstructure Modeling
Damage-Healing: Entropy Production
Nosonovsky, M, and B. Bhushan, 2010, Surface Self-organization: From Wear to Self-healing in Biological and Technical Surfaces. Applied Surface Science, 256, 3982-3987.
Nosonovsky, M., and S. K. Esche, 2008, A Paradox of Decreasing Entropy in Multiscale Monte Carlo Grain Growth Simulations. Entropy, 10(2), 49-54.
Nosonovsky, M., 2010, Entropy in Tribology: in the Search for Applications. Entropy, 12(6), 1345-1390.
Nosonovsky, N., R.Amano, J. M. Lucci and P. K. Rohatgi, 2009, Physical Chemistry of Self-organization and Self-healing in Metals. Phys. Chem. Chem. Phys., 11, 9530-9536.
The net entropy production of a damage-healing systems
Entropy Production in Damage-Healing
Pauli, A. T., 2014, Chemomechanics of Damage Accumulation and Damage Recovery Self-Healing in Bituminous Asphalt Binders. Dissertation, Printed by Sieca Repro, Delft, The Netherlands. ISBN 978-94-6186-269-3.
Entropy Production in Damage-Healing
Properties of the Oil Phase:
Viscous FlowDiffusion, Molecular Weight and Thermal
Fatigue
Entropy Production in Damage-Healing
Viscous Flow of Model Oils
0.00
1.00
2.00
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8.00
9.00
10.00
0 100 200 300 400 500 600 700
n-P
araf
fin v
isco
sity
, cen
tipoi
se
n-Paraffin molecular mass, g/mol
90°C
120°C
150°C
180°C
HPLC-Gel Permeation Chromatography
Thermal Gravimetric Analysis
Tvol vs. Molecular Mass
Viscous Flow of Neutral Oils
Rajbongshi, P., and A. Das, 2009, Estimation of Temperature Stress and Low-Temperature Crack Spacing in Asphalt Pavements. Journal of Transportation Engineering © ASCE, October 2009, 745-752.
Rajbongshi, P., and A. Das, 2008, Thermal Fatigue Considerations in Asphalt Pavement Design. Int. J. Pavement Res. and Technol., 1(4), 129-134.
Stress Build-up: Thermal Fatigue
Stress Build-up: Thermal Fatigue
a. b.
R² = 0.9561
0
0.0005
0.001
0.0015
0.002
0.0025
0 10 20 30
AB
S C
hang
e in
spe
cific
vol
ume
(-15°
C)
Percent Wax from IEC Neutrals
AAM-1
R² = 0.9483
0
0.0005
0.001
0.0015
0.002
0.0025
500 700 900 1100 1300A
BS
Cha
nge
in s
peci
fic v
olum
e (-1
5°C
)
IEC Neutrals Molecular Mass (Da)
AAG-1
AAM-1
Oils Molecular Mass vs. α
*Bahia, H. U., 1991, Low-Temperature Isothermal Physical Hardening of Asphalt Cements. PhD Dissertation.Civil Engineering Department, Penn State University. University Park, PA.
*
Thermal Stress vs. α
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250
MN1-2 MN1-3 MN1-4 MN1-5
Nor
mal
ized
Tra
nsve
rse
Cra
ck L
engt
h, (2
009)
(Lft)
Asphalt Source
2008 2009
Thermal Fatigue in Pavement
Thermal Fatigue in Pavement
Pauli, A. T., M. J. Farrar, and P. M. Harnsberger, 2012, Material Property Testing of Asphalt Binders Related to Thermal Cracking in a Comparative Site Pavement Performance Study. In Scarpas, A., N. Kringos, and I. Al-Qadi (Eds.), 2012, 7th RILEM International Conference on Cracking in Pavements Mechanisms, Modeling, Testing, Detection and Prevention Case Histories. Springer, The Netherlands, pp. 233-243.
Thermal Fatigue in Pavement
MN1-2
Thermal Fatigue in Pavement
Properties of the Maltene and Asphalt Phase:
Viscous Flow of Maltenes and Oils and Healing
Entropy Production in Damage-Healing
Viscous flow of maltenes
Viscous flow of asphalt
Viscous flow of asphalt (influence of temperature)
Viscous flow of asphalt (influence of temperature)
Lytton, R. L., C. W. Chen and D. N. Little, 2001, Microdamage Healing in Asphalt and Asphalt Concrete, Volume III: A Micromechanics Fracture and Healing Model for Asphalt Concrete, FHWA-RD-98-143. Federal Highway Administration, U. S. Department of Transportation, McLean, VA.
Flow Properties and Healing
Flow Properties and Healing
Entropy Production in Damage-Healing
Asphalt Microstructure and RAP Blending
Mix Model Mechanism
RAP-Asphalt Flow Properties
RAP-Asphalt Flow Properties
RAP-Asphalt Flow Properties
RAP-Asphalt Mixture Model
RAP-Asphalt Flow Properties
RAP-Asphalt Flow Properties
RAP-Asphalt Flow Properties
RAP-Asphalt Flow Properties
y = -288.05x2 + 36.892x + 87.192R² = 0.9067
0
10
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0.00 0.20 0.40 0.60
Pha
se A
ngle
Isooctane Asphaltene Mass Fraction
Viscous flow of asphalt
Surface Freezing and Crystallization in n-
ParaffinsA Model for Wax Surface Structuring in Bitumen
Entropy Production in Damage-Healing
Wax Surface-Freezing in Complex Media
Wax Surface-Freezing in Complex Media
Paraffin surface freezing “detected” byX-ray reflectivity and grazing incidence diffraction
X.Z. Wu, B.M. Ocko, E.B. Sirota, S.K. Sinha, M. Deutsch, B.H. Cao, M.W. Kim, Surface Tension Measurements of Surface Freezing in Liquid Normal Alkanes, Science, 261 (1993a) 1018-1020.
Wax Surface-Freezing in Complex Media
Wax Surface-Freezing in Complex Media
Wax Surface-Freezing in Complex Media
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surfa
ce te
nsio
n, d
yne/
cm
temperature, °C
hexadecanewax-oils highSTasphaltseicosanewax-oils lowSToils (waxless)
Surface tension versus temperature plots for material groups; asphalts, IEC neutral fraction oils and model paraffins.
Wax Surface-Freezing in Complex Media
Pauli, T., W. Grimes. J. Beiswenger and A. J. M. Schmets, 2014, Surface Structuring of Wax in Complex Media.
J. Mater. Civ. Eng., 10, Submitted August 27, 2013; doi:10.1061/(ASCE)MT.1943-5533.0001032.
Wax Surface-Freezing in Complex Media
Wax Surface-Freezing in Complex Media
Wax Surface-Freezing in Complex Media
Wax Surface-Freezing in Complex Media
Wax Surface-Freezing in Complex Media
1%
5%
10%
20%
Spin-cast, dried, then image
1%
5%
10%
20%
Wax Surface-Freezing in Complex Media
y = 0.5595x - 0.0142R² = 0.8947
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0 2 4 6
Cry
tallin
e M
ater
ial v
ia D
SC
Γ, fitting coefficient
y = 1.1936x + 0.6833R² = 0.9711
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
0 2 4 6
Per
cent
Wax
Ext
ract
ed fr
om IE
C N
eutra
ls
Γ, fitting coefficient
Wax Surface-Freezing in Complex Media
Sectorization and Rippling Morphologies in Paraffin
and Polymer Crystal Lamella
Why Bees?: CES, Sectorization, Tilt Angle
Why Bees?: CES, Sectorization, Tilt Angle
Why Bees?: CES, Sectorization, Tilt Angle
Why Bees?: CES, Sectorization, Tilt Angle
Cooling
Assemblage of
crystallites to micro single
crystals
Roughening in the crystal
Artificial Bees: Paraffin in paraffin oil
Paraffin micro-crystals present in different media
asphalt maltenes neutral oils
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Hea
ling
Rat
e In
dice
s
Mass % Wax per IEC Neutral
dh/dt
dh2/dt
Healing and Presence of Wax
Force-Flux Coupling
Conclusions
• The oils phase viscosity is driven by molecular weigh.• The maltene (i.e., the oils plus resins) may be considered a
polar associated solution, BUT, apparent molecular weight may be a big player in viscosity.
• The asphalt (maltene plus asphaltenes) is conveniently modeled as a nano-particle suspension. AGAIN, apparent molecular weight considerations may play a significant role in viscous flow.
• Activation energy models of viscosity work well to explain viscosity-temperature relationships of the nano-particle suspension model considered.
• The Oil’s molecular weight correlates with thermal contraction properties of asphalt, thus, thermal fatigue correlates with thermal contraction, ergo, oils molecular weight correlates with , thermal fatigue.
• Asphaltene content strongly contributes to stiffness of RAP mixtures.
Conclusions
• The “LIQUID” (behavior) of asphalt relates to fatigue-healing.
• Surface crystallization (Surface Freezing) of paraffin wax in complex media involves diffusion controlled crystallization. Bees are observed in both thermally and solvent treated materials.
• Crystals develop at a liquid-vapor interface due to lowering of the liquid-vapor surface free energy state relative to a liquid-solid + solid-vapor state.
• Oils and wax concentration are mutually related in terms of molecular weight, both of which relate to healing.
• Force-flux Coupling makes it difficult to pin-point a single compositional contributor to binder mechanical (rheological) behavior.
• IN SHROT: a chemomechanics model of bitumen behavior based in non-equilibrium statistical thermodynamics of asphalt microstructure is proposed to predict damage-