By:

Shu Wei Goh

Zhanping You, Ph.D., P.E.

Michigan Technological University

Laboratory Evaluation and the Mechanical Properties of Warm Mix Asphalt Using

Aspha-min®

OutlineIntroductionLiterature ReviewsObjectivesMaterial DescriptionsSample PreparationTest Descriptions & ResultsConclusions and Recommendations

IntroductionWhat is Warm Mix Asphalt (WMA)?

A technology that allowed the producers of Hot-Mix Asphalt (HMA) pavement material to lower the temperatures at which the material is mixed and placed on the road.

IntroductionHow does WMA works?

Reduced the viscosity of the asphalt binder at a given temperature and allowed the aggregate to be fully coated at a lower temperature.Aspha-min® Sasobit®WAM-Foam®Evotherm®Asphaltan B®

IntroductionBenefits of WMA:

Lower energy consumptionReduced mixing and compaction

temperatureEarlier traffic opening after construction due

to reduced cool down timeLower plant wearSlowed binder aging potentialLower fumes and emissions

Figure Above shows that the drum plant in Iron Mountain, MI. Lower emission released by Warm Mix Asphalt compare to Hot Mix Asphalt

Warm Mix Asphalt Hot Mix Asphalt

Literature ReviewsWMA with Aspha-min® has improved

workabilityWMA has similar performance

compared to HMA during the field testWMA made with Aspha-min® has

increase the potential of moisture damage

WMA made with Aspha-min® and Sasobit® has a lower rutting depth

ObjectivesEvaluate the binder properties using

Aspha-min® as an additiveEvaluate the performance of WMA

made with Aspha-min® obtained from laboratory tests.

Evaluate the WMA using Mechanistic-Empirical Pavement Guide (MEPDG) using laboratory results

Materials For Asphalt Binder TestAsphalt Binder:

Control:PG 64-28PG 52-34

WMA:PG 64-28 + 0.3% Aspha-min®PG 64-28 + 0.5% Aspha-min®PG 58-34 + 0.3% Aspha-min®PG 58-34 + 0.4% Aspha-min®PG 58-34 + 0.5% Aspha-min®

Materials For Asphalt Mixture Performance TestAggregate Source:

MichiganAsphalt Binder used:

PG 64-28Control Mix Type:

4E3Aggregate size up to 12.5mmDesigned traffic load less than 3 millions ESALs

WMA additive added:0.3% Aspha-min®0.5% Aspha-min®

Sample PreparationSample prepared according to

Superpave specificationAir Void Level:

4%Control - 4E3:

Compacting temperature: 142˚CWMA - 0.3% & 0.5% Aspha-min® :

Compaction temperature: 100˚C & 120˚C

Laboratory TestingAsphalt Binder Tests:

Dynamic Shear Rheometer (DSR)Rotational ViscometerBending Beam Rheometer (BBR)

Asphalt Mixture Performance Test:IDT Resilient Modulus TestDynamic Modulus TestAPA Rutting Test

DSR Test

Dynamic Shear Rheometer (DSR) is used to characteristic the viscous and elastic behavior of asphalt binders at high and intermediate service temperatures

DSR Test InputTemperature:

High Temperature (un-aged, RTFO aged):64˚C for PG 64-2858˚C for PG 58-34

Low Temperature (PAV and RTFO aged):22˚C

Frequency:10 rad/s

DSR Test Results

G*/sin() (KPa) G*∙sin() (KPa) High Temperature Low Temperature

Un-aged Binder Binder After RTFO

Aging Binder after PAV

aging Asphalt Binder 52°C 64°C 52°C 64°C 22°C

Control PG52-34 1.23 - - - - 0.3%AM_PG52-34 1.06 - - - - 0.4%AM_PG52-34 1.07 - - - - 0.5%AM_PG52-34 1.01 - - - - Control PG64-28 - 1.18 - 2.62 2064.30

0.3%AM_PG64-28 - 0.92 - 2.05 2639.20 0.5%AM_PG64-28 - 0.78 - 2.03 2813.80

Rotational Viscosity

Rotational Viscometer (RV) is used to find the viscosity of the binder.

Temperature tested:80˚C 100˚C120˚C135˚C165˚C

Binder Tested:PG 64-28PG 52-34

Viscosity Result: PG64-28

0.01

0.1

1

10

100

75 95 115 135 155 175

Temperature (Celsius)

Vis

cosi

ty (

Pa.

s)

Control PG64-28

0.3%AM_PG64-28

0.5%AM_PG64-28

Power(0.5%AM_PG64-28)Power(0.3%AM_PG64-28)Power (Control(PG64-28

Viscosity Result: PG52-34

0.01

0.1

1

100 120 140 160 180

Temperature (Celsius)

Vis

cosi

ty (

Pa.

s)

Control PG52-34

0.3%AM_PG52-34

0.4%AM_PG52-34

0.5%AM_PG58-34

Bending Beam Rheometer (BBR)

BBR is used to determined asphalt binder’s propensity to thermal cracking at low pavement service temperature.

The BBR uses a transient creep load, applied in the bending mode, to load an asphalt beam specimen held at a constant low temperature.

BBR Creep Stiffness Result

Asphalt Binder Average Stiffness

(MPa) Average m-value

Control 210.5 0.315 0.3% Aspha-min 193.75 0.317 0.5% Aspha-min 191.83 0.321

* M-value is the slope of the log creep stiffness versus log time

curve at 60 second during the test

IDT Resilient Modulus Test

Load apply:250KN

Temperature tested:-4˚C21.3˚C 37.8˚C54.4˚C

IDT Resilient Modulus Result

0

4000

8000

12000

16000

20000

Control 0.3%AM_100C

0.3%AM_120C 0.5%AM_100C

0.5%AM_120C

Sample

Re

silie

nt

Mo

du

lus

(M

Pa

)

-4C

-4C

-4C -4C -4C

21.1C 21.1C

21.1C 21.1C

21.1C

37.8C 37.8C37.8C 37.8C 37.8C

54.4C 54.4C 54.4C 54.4C 54.4C

Dynamic Modulus Test

Determined by applying sinusoidal vertical loads to cylindrical samples while measuring the deformation

Dynamic Modulus InputsFrequency used:

0.1Hz, 0.5Hz, 1Hz, 5Hz, 10Hz, and 25HzTemperature tested:

-5˚C4˚C21.1˚C

The recoverable axial micro-strain in this test was controlled within 50 and 100 micro strain so that the material is in a viscoelastic range

Dynamic Modulus Result

0

5000

10000

15000

20000

25000

30000

0.1 1 10 100Frequency (Hz)

Dyn

amic

Mo

du

lus

(MP

a)

Control0.3%AM_100C0.3%AM_120C0.5%AM_100C0.5%AM_120 -5˚C

4˚C

21.1˚C

APA Rutting

The purpose of this test is to evaluate the rut resistance of the asphalt mixture and the rut depth was measured using the Asphalt Pavement Analyzer machine.

APA Rutting InputsTemperature used:

64˚CLoad applied:

100lbsDuration of the test:

8000 cycles

APA Rutting Result

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

6

0 2000 4000 6000 8000 10000

Number of Cycle

Ru

t D

epth

(m

m)

Control

0.3%AM_100C

0.3%AM_120C

0.5%AM_100C

0.5%AM_120C

Mechanistic-Empirical Pavement Design Guide (MEPDG)Developed under the National Cooperative

Highway Research Program (NCHRP) Project 1-37A

Able to predict the development and propagation of various kinds of pavement distressRutting and fatigue crackingUsing input data on asphalt mixture

characteristics obtained from laboratory testing.

MEPDG InputsHierarchical levels used in

predicting the asphalt pavement performance:Level 1

Design pavement life:20 years

MEPDG Result

Control

0.3 AM_100C

0.3 AM_120C0.5 AM_100C0.5 AM_120C

0.09

0.18

0.27

0.36

0.45

0.54

0.63

0.72

0 50 100 150 200 250 300

Month

Dep

th (

inch

.)

Control

0.3 AM_100C

0.3 AM_120C

0.5 AM_100C

0.5 AM_120C

ConclusionsThe additional Aspha-min® does not

significantly affect the binder’s viscosity. The additional Aspha-min® slightly

decreased the G* at high temperature and increased the G* at low temperature through DSR test.

The additional Aspha-min® has slightly reduced binder’s creep stiffness through BBR test

ConclusionsThe additional Aspha-min® does not

significantly affect the resilient modulusThe additional Aspha-min® decreased

the rutting depth through the APA test. The rutting depth decrease when compaction temperature for WMA increased

WMA compacted at 120˚C has shown a higher performance overall for E* through dynamic modulus test

ConclusionsThe additional Aspha-min® decreased

the predicted depth of rutting based on a level 1 analysis using the MEPDG

RecommendationsLife cycle cost and life cycle assessment

analysis should be performed to evaluate whether Aspha-min® will give any advantage or disadvantage in terms of sustainable development.

The performance grade of asphalt binder with the additional Aspha-min® should be examined for each project before the construction.

RecommendationsThe long-term performance in the field

should be monitored.A guideline of the design, construction,

and maintenance of WMA is needed for successful field applications.

Main ReferencesHurley, G.C., Evaluation Of New Technologies For

Use In Warm Mix Asphalt, in Civil Engineering Department. 2006, Auburn University: Auburn. p. 231.

Hurley, G.C., B.D. Prowell, G. Reinke, P. Joskowicz, R. Davis, J. Scherocman, S. Brown, X. Hongbin and D. Bonte. Evaluation of Potential Processes For Use In Warm Mix Asphalt Savannah, GA, United States: Association of Asphalt Paving Technologist, White Bear Lake, MN 55110, United States. 2006.

Prowell, B.D., G.C. Hurley and E. Crews, Field Performance of Warm-Mix Asphalt at the NCAT Test Track, in Transportation Research Board 86th Annual Meeting. 2007: Washington DC, United States.

Main ReferencesFHWA. Warm Mix Asphalt Technologies and

Research. 2007 [cited 2007]; Available from: http://www.fhwa.dot.gov/pavement/asphalt/wma.cfm.

Wasiuddin, N.M., S. Selvamohan, M.M. Zaman and M.L.T.A. Guegan, A Comparative Laboratory Study of Sasobit® and Aspha-min® in Warm-Mix Asphalt, in Transportation Research Board 86th Annual Meeting. 2007: Washington DC, United States.

Barthel, W., J.-P. Marchand and M.V. Devivere. Warm Asphalt Mixes By Adding A Synthetic Zeolite. Eurasphalt & Eurobitume Congress 2004 Proceedings. 2004

Main ReferencesKristjansdottir, O., Warm Mix Asphalt for Cold

Weather Paving, in Civil and Environmental Engineering. 2006, University of Washington: Seattle.

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