Update/status: 4 di ll l l t DSR4 mm diam. parallel plate DSRMichael J. Farrar (mfarrar@uwyo.edu)

Changping Sui William H. Tuminello

Thomas F. TurnerThomas F. Turner

Western Research Institute

P3 SymposiumLaramie, Wyoming

July 15 2010July 15, 2010

Acknowledgementsg

• This work is funded by Federal Highway Administration under contract number: DTFH61-07-D-00005

• University of Wyomingy y g• Dave Walrath, Professor of Mechanical

Engineeringg ee g• Lee Stutzman, graduate student in

Mechanical EngineeringMechanical Engineering

Outline

• Brief introduction to 4mm DSR and machine compliance

BBR s 4mm DSR• BBR vs. 4mm DSR

• Thermal stress build-up calculated from 4mm DSR and BBR

• Extensional creep compliance with• Extensional creep compliance with DTT specimens

• Future work

Methodology

Dynamic Shear Rheometer (DSR) with 4 mm diam. Parallel-plates

P bl E d t i t t li t l t t---- Problem: Error due to instrument compliance at low temperature

---- Solution: Correct compliance error: • using method developed by Schröter et al.1(corrected manually)

• real time correction conducted by software(corrected automatically)

Plate radius = 2 mmSample height = 1.5 ~ 1.75 mmSample volume = 18 84 ~ 21 98 mm3Sample volume = 18.84 ~ 21.98 mmSample weight = ~20 mg

1 K. Schröter, S. A. Hutcheson, X. Shi, A. Mandanici, and G. B. McKenna, J. Chem. Phys. 125, 2006, 214507.

4 mm parallel plates – G* Mastercurve – corrected and uncorrectedcurve corrected and uncorrected

G* Master Curves from Data Collected on Different Plate Sizes by Different OperatorsDifferent Plate Sizes by Different Operators

2010 TRB paper highlightsp p g g

• Low temperature data was corrected for instrument compliance using two methodscompliance using two methods

• Reproducibility of the data was demonstrated using same conditions different plate sizes different machines and fromconditions, different plate sizes, different machines, and from different operators

• After compliance corrections, it has been demonstrated that the p ,4 mm technique is a reliable, fast, and simple test method to measure low temperature properties of asphalt binders with small samples (~20 mg)

New Technique for Measuring Low-Temperature Properties of Asphalt Binders with SmallNew Technique for Measuring Low Temperature Properties of Asphalt Binders with Small Amount of Materials, C. Sui, M.J. Farrar, W.H.Tuminello, T.F. Turner, TRB 2010

New reports comingp g

A New Low-temperature Performance Grading Method U i 4 P ll l l DSRUsing 4 mm Parallel-plates on a DSRChangping Sui, Michael J. Farrar, P. Michael Harnsberger,

William H. Tuminello, Thomas F. TurnerWilliam H. Tuminello, Thomas F. Turner

Evolution of Unmodified Asphalt Binder Complex Shear Modulus Model Parameters with Oxidative Aging

Using 4 mm Parallel-plates on a DSRMi h l J F R Gl Ch i S i Shi Ch HMichael J. Farrar, Ron Glaser, Changping Sui, Shin-Che Huang,

Thomas F. Turner, P. Michael Harnsberger

ASTM specificationp f

ASTM D7175 – 08ASTM D7175 08

Standard Test Method for Determining the Rheological Properties of Asphalt Binder Using a Dynamic Shear Rheometer

Interconversion

Adapted from [Emri, I. et al 2005]

S(t) – BBR vs. 4mm DSR( )

Thermal stress build-up cont.

Creep test setupp p

Extensional creep testp

0.006

0.004

0.005

0.003

Strain

0 001

0.002

0

0.001

0 500 1000 1500 2000 2500 3000 3500 40000 500 1000 1500 2000 2500 3000 3500 4000

Time (s)

Comparison BBR, 4mm, extensional creep testc eep test

Future work

• Perform 4 mm DSR on recovered binder from cores and binder from thin film aging studies

• Complete low-temperature shear creep and tensile creep tests and compare the results to BBR data

• Emulsion residue – how well can BBR S(t) and m-value be estimated from intermediate temperature DSR

• Crack sealant

• Adapt ARC DSR binder fatigue test(s) to 4 mm plate DSR

• Adapt ARC DSR binder healing test(s) to 4 mm plate DSR

Questions?

THANK YOU !

Methodology cont.gy

Manual correction - using method developedb S h öt t l [2006]

111

by Schröter et al. [2006]

tsmes KKK **

RGK4

tsmes KRGh

RGh 1

*2

*2

44

hGK

2

K*mes is the measured complex torsional stiffness K*s is the actual complex torsional stiffness of the

sample Kt is the machine torsional stiffness. G is the shear modulusG is the shear modulush is the gapR is the plate radius