Asphalt Technology Guidance Program

(ATGP)

Ohio Transportation Engineering ConferenceOctober 10, 2017

Long-Life Asphalt Pavement for the 21st Century

Office of Asset Management,

Pavements, & Construction

Agenda

• FHWA Pavement and Materials

• Trailer Activities

• Aggregate Imaging System (AIMS)

• Asphalt Mixture Performance Tester (AMPT)

• Questions and Tour

2

Pavement & Materials Discipline

• Program Office

– Office of Asset Management, Pavements, and Construction (FHWA HQ, Washington, DC)

• ATGP: Mobile Asphalt Testing Trailer (MATT) and Asphalt Binder Testing Laboratory (ABTL)

3

Pavement & Materials Discipline

• Program Office

– Office of Asset Management, Pavements, and Construction (FHWA HQ, Washington, DC)

• ATGP: Mobile Asphalt Testing Trailer (MATT) and Asphalt Binder Testing Laboratory (ABTL)

• Research and Development

– Office of Infrastructure R&D (Turner-Fairbank Highway Research Center, McLean, VA)

4

Pavement & Materials Discipline

• Program Office

– Office of Asset Management, Pavements, and Construction (FHWA HQ, Washington, DC)

• ATGP: Mobile Asphalt Testing Trailer (MATT) and Asphalt Binder Testing Laboratory (ABTL)

• Research and Development

– Office of Infrastructure R&D (Turner-Fairbank Highway Research Center, McLean, VA)

• Technical Services (Resource Centers)

– Atlanta, Baltimore, Chicago, Denver

5

Pavement & Materials Discipline

• Program Office

– Office of Asset Management, Pavements, and Construction (FHWA HQ, Washington, DC)

• ATGP: Mobile Asphalt Testing Trailer (MATT) and Asphalt Binder Testing Laboratory (ABTL)

• Research and Development

– Office of Infrastructure R&D (Turner-Fairbank Highway Research Center, McLean, VA)

• Technical Services (Resource Centers)

– Atlanta, Baltimore, Chicago, Denver

• Division Offices (nationwide) 6

MATT Program History

• Projects began in 1988

– DP 74: Field Management of Asphalt Mixes Using Volumetric Quality Control

• Transition to Superpave implementation

– Early-1990s

– Classroom and hands-on training

• Transition to performance-related specifications

– Shadow testing

– AMPT user since 2003!

• Innovative materials and practices

– WMA, GTR, RAP/RAS, increased density7

MATT in Ohio

• 1988 – Standard Materials, Jackson

– DP 74: Field Management Using Volumetric Quality Control

• 1994 – Ohio DOT, Columbus

– Superpave Level 1 Training

• 1995 – STONECO, Marion

– SPS-9 Project: Level 1 Superpave

• 2017 – Here and now!

8

9

Program Objective

• Provide Support to National Initiatives

– Increased Pavement Density

– Increased RAP/RAS Usage

– Understanding Asphalt Rubber Testing

– Mixture Performance Testing and the AMPT

– Stone Matrix Asphalt

– Binder Performance Testing

– Long-Term Aging

MATT Technology

• Equipment Development & Refinement

– Simple Performance Tester (SPT)

• Evaluation and Refinement of Innovative

Contracting Concepts

• Development of New QA Concepts for HMA

• Advanced Rapid Test Tools

– AIMS, CoreLok, CoreDry

10

11

Routine Project Site Activities

•Material Characterization

•Mix Design Replication and Testing

•Mix Production Testing

Binder Tests and Analysis

12

Binder Characterization

TEST PROCEDURES EQUIPMENT

• RV

• DSR

• RTFO

• PAV

• Vacuum Degassing Oven

• BBR

• DTT

• ABCD

• Torsional bar testing

13

• Performance Grading

– AASHTO M 320

– AASHTO M 332 (MSCR)

– AASHTO R 49 (Low Temperature PG)

• Solubility & Separation

– AASHTO T 44

– ASTM D7173

Additional DSR Testing

• Parallel Plate (PP) Geometry

– Frequency Sweep (Master Curve)

– Linear Amplitude Sweep (AASHTO TP 101)

– 4mm test

• Cylindrical Geometry

– Viscosity: AASHTO T 316

– Asphalt Rubber Testing

14courtesy of Anton Paar & TA Instruments.

DSR Testing Alternative: Asphalt Rubber Binder

Can it fit within existing PG grading system?

• DSR Testing Geometry

– Caltrans, University of California Pavement Research Center, Anton Paar

– Concentric Cylinder (CC) development testing evaluation looks promising

– CC test geometry may overcome specimen preparation limitations of PP geometry

– Draft AASHTO standard in development

15

• Advantage– GTR modified asphalt can be measured with

particle sizes up to 2 mm

– No trimming problems and filling problems

– No edge effects 16

Concentric Cylinder Geometry

courtesy of Anton Paar

Rheological Properties:Master Curve

• Rheological parameter:

– Rheological index (R value)

– Crossover frequency (ωc)

– Glover-Rowe (G-R)

• These parameters can be interrelated from understanding the relationship between loading time (or frequency) and temperature.

17

Extended Aging

Do current procedures provide similarly aged material compared to long term aging in the field?

• Binder: PAV procedure (AASHTO R 28)

– ETG task force evaluating 40 h PAV

– Rheological parameters are used to assess

• Mixture: Oven aging (AASHTO R 30)

– NCHRP 9-54 is underway to investigate the need for extended aging

18

Long Term Conditioning:

19

Master Curve - PG 76-22 Asphalt Rubber

• More conditioning causes the master curves to become flatter with R increasing and ωc decreasing.

Low Temperature BBR Test:Binder New Parameter (∆Tc)

• ∆Tc is the difference between the critical low temperature determined by stiffness and relaxation criteria from BBR test

– ∆Tc = S critical temp - m critical temp

• As an asphalt binder ages, ∆Tc value becomes more negative

– Indicating a loss of relaxation properties

• Important parameter related to asphalt binder durability

• Threshold of -5°C being evaluated

20

Low Temperature ABCD Test:AASHTO TP 92

• Asphalt Binder Cracking Device (ABCD)

– Cracking Temperature

– Fracture Stress

– Low Temperature Grade

21

courtesy of EZ Asphalt Technology.

Long Term Conditioning:Low Temperature - PG 76-22 Asphalt Rubber

• Reasonable agreement between the three measurements for 20 hours PAV conditioning

• Doubling PAV time:

– 1.1 °C ↑ of cracking temp (ABCD)

– 3.2 °C ↑ of cracking temp (Table 1)

– 1.9 °C ↑ of cracking temp (Table 2) 22

PAV

Conditioning

Time

(h)

AASHTO M

320 Table 1

Intermediate

Temperature

Continuous

Grade

(°C)

AASHTO M

320 Table 1

Low

Temperature

Continuous

Grade

(°C)

AASHTO M

320

Table 1

∆ Tc

(°C)

AASHTO M

320 Table 2

Critical

Cracking

Temperature

(°C)

ABCD Low

Temperature

Grade

(°C)

ABCD

AASHTO TP

92

Cracking

Temperature

(°C)

20 18.5 -27.7 -2.3 -27.7 -28.6 -35.5

40 18.5 -24.5 -5.2 -25.8 -27.7 -34.4

Aggregate and Volumetric

Testing and Analysis

23

Aggregate Characterization

• Physical Properties, AASHTO M-323– Sieve Analysis – AASHTO T 11 & T 27

– Specific Gravity & Absorption – AASHTO T 84 & T 85

– Flat & Elongation – ASTM D4791

– CA Angularity – AASHTO T 335

– FA Angularity – AASHTO T 308

– Sand Equivalent – AASHTO T 176

– Shape & Texture (AIMS) – AASHTO PP 64 & TP 81

• Angularity

• Shape

• Texture

24

25

Masad et al. (2003)

TP 81-12

AIMS

AIMS Output - Example

26

Low HighMedium

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20

% o

f P

art

icle

s

AIMS Form2D

AIMS Form2D Distribution

0.075 (#200)_RAP 0.15 (#100)_RAP

0.30 (#50)_RAP 0.60 (#30)_RAP

1.18 (#16)_RAP 2.36 (#8)_RAP

Low Medium High

0

10

20

30

40

50

60

70

80

90

100

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

% o

f P

art

icle

s

AIMS Angularity Index

AIMS Angularity Distribution

0.075 (#200)_RAP 0.15 (#100)_RAP

0.30 (#50)_RAP 0.60 (#30)_RAP

1.18 (#16)_RAP 2.36 (#8)_RAP

4.75 (#4)_RAP 9.5 (0.375)_RAP

12.5 (0.50)_RAP 19.0 (0.75)_RAP

Low Medium High

0

10

20

30

40

50

60

70

80

90

100

0 100 200 300 400 500 600 700 800 900 1000

% o

f P

art

icle

s

AIMS Texture Index

AIMS Texture Distribution

4.75 (#4)_RAP 9.5 (0.375)_RAP

12.5 (0.50)_RAP 19.0 (0.75)_RAP

LowMedium High

0

10

20

30

40

50

60

70

80

90

100

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

% o

f P

art

icle

s

AIMS Sphericity (SP)

AIMS Sphericity Distribution

4.75 (#4)_RAP

9.5 (0.375)_RAP

12.5 (0.50)_RAP

19.0 (0.75)_RAP

27

1:5

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Elo

ngation R

atio (

Inte

rmedia

te/L

ong)

Less E

longate

d �

Flatness Ratio (Short/Intermediate) Less Flat �

4.75 (#4)_RAP 9.5 (0.375)_RAP

12.5 (0.50)_RAP 19.0 (0.75)_RAP

Elongation vs Flatness

AIMS Output - Example

28

FAA

CAA –fractured faces

F&E (3:1 & 5:1)

Aggregate

Type

AIMS TP 81 ASTM D 5821

CAA RankCAA

RankCAA

Rank

(+1) (+2)

#7 2637 4 100 1 100 1

#8 2954 1 100 1 100 1

Birdseye 2762 3 100 1 100 1

#10 Wash 2834 2 -- -- -- --

RAP 2585 5 98 2 95 2

Aggregate

Type

AIMS TP 81 ASTM D 4791

F&E

(3:1)Rank

F&E

(5:1)Rank

F&E

(3:1)Rank

F&E

(5:1)Rank

#7 22.2 4 3.0 4 0 1 0 1

#8 27.7 5 9.3 5 0 1 0 1

Birdseye 7.8 3 0.0 1 -- -- -- --

#10 Wash 1.6 1 0.6 2 -- -- -- --

RAP 6.9 2 1.5 3 0 1 0 1

Aggregate

Type

AIMS TP 81 AASHTO T 304

FAA Rank FAA Rank

#7 3009 4 44.8 4

#8 2899 5 45.1 3

Birdseye 3166 1 44.5 5

#10 Wash 3164 2 50.6 1

RAP 3017 3 46.5 2

Mix Design Replication

• Use Plant Site Materials

29

Mix Design Replication

30

•Mixing, Aging, Compacting

Mixture Production Testing

31

Asphalt Mixture Sample

Volumetric Properties

Pb – Ignition (T 308)

Gradation – (T 30)

Gmm – Rice (T 209)

Gmb – (T 166)

- Corelok (T 331)

- Gilson SG 4 (TP 82)

Performance Testing

Dynamic Modulus (TP 79)

- Unconfined

Flow Number (TP 79)

- Confined

- Unconfined

Cyclic Fatigue (TP 107)

Gilson SG-4

• AASHTO TP 82 “Bulk Specific Gravity of Compacted Bituminous Mixtures Using Water Displacement Measured by Pressure Sensor”

32Courtesy of Gilson Company, Inc.

Corelok

AASHTO T 331 – “Bulk Specific Gravity (Gmb) and Density of Compacted Hot Mix Asphalt (HMA) Using Automatic Vacuum Sealing Method”

33CoreLok, courtesy of InstroTek, Inc.

Rapid Test Tools

CoreDry

• ASTM D7227– “Standard Practice for Rapid Drying of

Compacted Asphalt Specimens by using Vacuum Drying Apparatus”

• Rapid Vacuum Drying

– Alternating cycles of Vacuum and Heating

• Maintains Sample at Room Temperature

34

Mixture Performance Testing

and Analysis

35

Performance Characteristics

• Asphalt Mixture Performance Tester

IPC Global

36

AMPT – addressing a need

• Late 1980s-Early 1990s: Strategic Highway Research Program• Superpave mixture design approach

• Performance grade binders

• But no viable performance tests for mixture

• National Cooperative Highway Research Program• 9-19: Identify simple performance tests for Superpave (rutting,

fatigue)• Dynamic modulus, flow number, flow time

• 9-29: Produce test methods and prototype, conduct ruggedness and interlaboratory studies• Simple Performance Tester (now known as AMPT) was born!

37

AMPT

• Temperature range from about 4°to 70°C

• Computer-controlled device

• Software built-in for various test procedures

• Fundamental tests

• Stress and strain modeling

• “Bulk testing”

• Pavement ME

• Kits available for other tests

38

39

AMPT Overview

40

Gauge Point Gluing System

Dynamic Modulus Test

• Mixture Stiffness• Rutting• Fatigue Cracking

41

Stress

Strain

σ ε00

lΤ

Τp

Time

σ

εE*

0

0=

Dynamic Modulus Phase Angle

Τ

Τφ

p

l= (360)

Reduced Frequency, Hz

Dynamic Modulus Master Curve

10,000,000

1,000,000

100,000

10,000

1,000

E*,psi

115°F

70°F

40°F

FIT

1.0E-06 1.0E-04 1.0E-02 1.0E+00 1.0E+02 1.0E+04 1.0E+06

E*min=4,259 psi

E*max=3,376,744 psi

R2= 0.9978Se/Sy= 0.038 3

2

1

0

-1

-2

-3

Log S

hift Fact

or

0 50 100 150

Temperature

42

AMPT Cyclic Fatigue

• Fundamental, repeated loading test

• Direct tension (pull-pull)

• Small-specimen testing available

• AASHTO TP 107 – revisions out for ballot!

• Material behavior across all possible

loading conditions!

43

AMPT Cyclic Fatigue Process

Preparation

- Cylindrical specimen

- 100 mm x 130 mm

- Small-specimen: 38 mm x 110 mm

- End plate gluing, clamp system being

explored

- 2-3 days for mix

Testing

- Dynamic modulus fingerprint for specimen

variability

- Pull-pull fatigue test

- Strain level based on TFHRC database

- Test temperature based on location of

interest

- Load until crack forms

- 1-2 days for mix

Analysis

- AMPT automatically captures data for

analysis

- Calculate damage via spreadsheet or software

- Assign mixture rankings or use

pavement prediction software

- 1-2 hours for mix

44

AMPT Cyclic Fatigue field

validation

• Pavement prediction software built from models

• Field validation

• 59 mixtures

• 55 different pavement structures

• Develop laboratory-to-field transfer functions

• Built for use in a PRS framework…

45

AMPT Cyclic Fatigue advantages

• Standard sample preparation

• AASHTOWare Pavement ME compatible

• Ruggedness, precision and bias underway

• Commercial software available

• Spreadsheet analysis & formulation available

• Predicts performance!

• Material behavior across all possible loading/temperature conditions!

46

AMPT implementation

• Transportation Pooled Fund Study (TPF(5)-178)• Purchase, installation of 29 AMPTs • NHI Course (over 80 trainees)• Interlaboratory study on effect of air voids• National workshop• Equipment specification, and others!

• Test standard development, improvement, and revision

• Instructional videos, TechBriefs

• PRS shadow implementation (TFHRC-led)

• MATT projects/training

• User Groups at TRB and regional meetings47

AMPT Users Groups

• National/International

• TRB Annual Meeting

• Discussion of issues, best practices, future efforts

• 164 members, 28 DOTs present

• Regional

• User-Producer Groups

• State Asphalt Paving Assoc. meetings

48

MATT Staff

• Federal Highway Administration (FHWA HQ)

– Matthew Corrigan, Sr. Asphalt Pavement Engineer

– David Mensching, Asphalt Pavement Engineer

• ESC, Inc. (FHWA Contractor)

– Chuck Paugh, Senior Project Manager

– Mary Luz Echeverria, Project Administrator

– Amir Golalipour, Baron Colbert, Satish Belagutti, Project Engineers

– Warren Day, Anthony Fernandez, Steve Portillo, David Heidler, Laboratory Technicians

49

Technical assistance

• If you have upcoming projects where you’d like MATT technical assistance, contact:

– Dave Mensching, david.mensching@dot.gov, 202.366.1286

– Matt Corrigan, matthew.corrigan@dot.gov, 202.366.1549

– Chuck Paugh, chuck.paugh.ctr@dot.gov, 202.366.6640

50

• Trailer is parked outside!

• Come in for a tour!

• We’re here to assist! Please stop by anytime for more discussion.

• Questions?

Closing notes

51

Mix Design Replication

Mix Design Replication

3 Points

Performance Test Specimens

• 4 Replicates per Pb

Ignition Furnace Correction Factor

52

Mixture Production Testing• Volumetric Determination

– Pb

– VMA

– Va

– VFA

– Pbe / 0.075 mm

53

HMA Production Testing

HMA Sample

• Pb

• Ignition• Gradation• T 30• Gmm

• Gmb

• T 166• CoreLok

• Performance Specimens• 4 - Replicates

• Dynamic Modulus (E*)• Unconfined

• Flow Number• Unconfined

54

Performance Sample Preparation

55

IPC ServoPac

• ServoPac Gyratory Compactor

– Capable of measuring Shear Resistance

– Compacts tall specimens required for fabrication of SPT specimens

Additional HMA Technology

ServoPac Shear

Mix Design Replication Volumetrics

400

410

420

430

440

450

460

470

480

490

500

0 20 40 60 80 100 120 140 160

Gyrations

Sh

ea

r

56

ServoPac Gyratory CompactorServoPac Shear

Mix Design Replication Volumetrics

400

410

420

430

440

450

460

470

480

490

500

0 20 40 60 80 100 120 140 160

Gyrations

Sh

ear

57

Extrapolation vs Full Height

1.10

1.12

1.14

1.16

1.18

1.20

1.22

1.24

1.26

1.28

1.10 1.12 1.14 1.16 1.18 1.20 1.22 1.24 1.26 1.28

Internal Angle - Full Height Specimen (deg)

Inte

rna

l A

ng

le -

Ex

tra

po

late

d

(de

g)

AFG1A

AFGC 125X

Interlaken

Test Quip

1:1 Line

"+0.02" line

"-0.02" line"Best Fit" line:

y = 0.9554 x + 0.0493

r2 = 0.916

58

Extrapolation

DAV Loaded Angle at Top of Specimen

Specimen Height DAV angle Date Specimen

36 mm 1.218 degrees 22-Jul-2002 DAV4-2

37 mm 1.216 degrees 22-Jul-2002 DAV4-4

36 mm 1.206 degrees 22-Jul-2002 DAV4-6

70 mm 1.192 degrees 22-Jul-2002 DAV4-8

70 mm 1.191 degrees 22-Jul-2002 DAV4-10

70 mm 1.181 degrees 22-Jul-2002 DAV4-12

DAV Loaded Angle at Bottom of Specimen

Specimen Height DAV angle Date Specimen

27 mm 1.221 degrees 22-Jul-2002 DAV4-1

27 mm 1.214 degrees 22-Jul-2002 DAV4-3

27 mm 1.209 degrees 22-Jul-2002 DAV4-5

61 mm 1.207 degrees 22-Jul-2002 DAV4-7

61 mm 1.196 degrees 22-Jul-2002 DAV4-9

61 mm 1.192 degrees 22-Jul-2002 DAV4-11

• 2 Heights – top & bottom

59

Rapid Test Tools

CoreLok• Marketed by Instrotek Inc.

• Versatile device– Gmm (ASTM D6857)

– Gmb (AASHTO T 331, ASTM D6752)

– Gsb – for CA & FA

– Effective Porosity (ASTM D7063)

• Vacuum Sealing Procedure

• NCAT Ruggedness Study

• Round-Robin to establish AASHTO Precision Statement

60