2019 NEC/AAAE Airports Conference Hershey, PA March 28, 2019 830 Coc45_F… · Hershey, PA March...

Ronald Corun

Specialty Products Manager

Associated Asphalt Partners, LLC

2019 NEC/AAAE Airports Conference

Hershey, PA

March 28, 2019

Background

Airports experience fuel and hydraulic oil spills on aprons and taxiways Fueling operations

Aircraft sitting in queues

Softens (weakens) asphalt

Causes permanent deformations and failuresIndentations in Taxiway GG at

LaGuardia Airport

Fuel Resistant Pavement Sealers Coal tar sealers are

most commonly used to protect Hot Mix Asphalt pavements from fuel damage

Different coefficient of expansion for coal tar causes substantial alligator cracking within 2-3 years

Cracking allows fuel penetration - short service life

Coal tar sealers are carcinogenic MSDS – “Unusual Chronic

Toxicity: May cause cancer of the skin, lungs, kidney and bladder.”

Adding carcinogenic material to pavement that may be recycled – future exposure

Development of Fuel-Resistant PMA

Developed test to measure

fuel resistance

Weigh 4 Marshall samples

after compaction

Immerse in jet fuel for 24

hours

Remove samples from fuel

bath, dry and weigh

Average weight loss of 4

Marshall specimens must

be less than 1.5%

Development of Fuel-Resistant PMA

Standard Hot Mix Asphalt

mixture loses 10% weight

from 24 hour soak in jet

fuel

Standard Polymer

Modified Asphalt (PG 76-

22) loses 5-6% weight

after 24 soak in jet fuel

Fuel Resistant PMA –

less than 1.0% weight

loss

Fuel-Resistant PMA Usage

First Fuel Resistant

Construction Project–

La Guardia Airport in

2002

Test section on Taxiway

GG – 450 tons

Asphalt Pavement Analyzer (APA) - Rutting

Evaluation of HMA

- Moving wheel load (100 lbs) applied to

a pressurized hose (100 psi) which lies

on top of asphalt samples

- Tested at 64oC for 8,000 loading

cycles

- Computer data acquisition system

StellarFlex FR – Rut Resistance

0

2

4

6

8

10

12

PG 64-22 PG 76-22 PG 82-22 StellarFlexFR

10.2

6.8

4.3

1.6

APA Rutting, mm

StellarFlex FR Fatigue Test Flexural Beam Fatigue

Device, AASHTO T-321 Tests mix’s ability to

withstand repeated bending which causes fatigue failure

Data = number of loading cycles to failure (loss of stiffness)

Failure occurs when stiffness of beam < 50% of initial stiffness

Test parameters – 1000 micro strain, 15°C, 10 HZ

StellarFlex FR – Crack Resistance

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

PG 82-22 StellarFlex FR

4200

45000

Flexural Beam Fatigue, Cycles to Failure

Fuel-Resistant PMA Usage – La Guardia

Placed Fuel-Resistant

PMA on Taxiway GG

at La Guardia Airport

August 2002

Graded as PG 94-22

Pumped into plant at

330°F

Produced mix at

340°F

Placed in silo for 4

hours


Paved at 330°F

No problems with placement

Handwork and longitudinal joints look good

Density achieved

Paving crew could not see a difference in Fuel-Resistant PMAmaterial from standard PMA


Inspected fuel resistant pavement in October 2003

Excellent condition No rutting

No cracking

No surface deterioration

2018 – still performing well, only pavement at LaGuardia not rutted

Fuel Resistant Specification

Working with engineers at MassPort, developed generic specification for fuel resistant HMA

Minimum PG 82-22 polymer modified asphalt

○ Pass fuel resistance test

○ Minimum 85% Elastic Recovery

Standard test method for fuel resistance

½” P-401 Mix #3

○ 50 blow Marshall design

○ Design at 2.5% air voids

Result – asphalt mix with outstanding rut resistance, crack resistance, and durability that also resists jet fuel damage

Fuel-Resistant Usage – Logan Airport

First use of

modified P-401

mix with FR binder

at Boston Logan

Airport


Placed 1300 tons

of fuel resistant

mix on Taxiway N

and Runway 4L-

22R at Logan

Airport in June

2004

StellarFlex FR at Logan Airport


FR Asphalt graded as PG 94-22

1/2” P-401 mix designed at 2.5% air voids

7% asphalt content design target

MassPort engineers concerned about rutting

APA testing at Worcester Polytechnic Institute

Worcester Polytechnic Institute –

APA Rut Testing

0

1

2

3

4

5

3/4" P-401Mix

1/2" P-401Mix

3/4" FR Mix 1/2" FR Mix

3.6

4.1

0.90.7

APA Rutting, mm

Logan P-401 vs FR Mix

Asphalt Mix Performance Tester (AMPT)


AMPT Dynamic Modulus (STOA)

1,000

10,000

100,000

1,000,000

10,000,000

1.0E-07 1.0E-05 1.0E-03 1.0E-01 1.0E+01 1.0E+03 1.0E+05 1.0E+07

Dy

na

mic

Mo

du

lus

(psi

)

Loading Frequency (Hz)

P601 - STOA

Logan Airport - STOA


AMPT Dynamic Modulus (LTOA)

1,000

10,000

100,000

1,000,000

10,000,000

1.0E-07 1.0E-05 1.0E-03 1.0E-01 1.0E+01 1.0E+03 1.0E+05 1.0E+07

Dy

na

mic

Mo

du

lus

(psi

)


P601 - LTOA

Logan Airport - LTOA


AMPT Flow Number

7908

364

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

P601 Logan Airport

STOA

Rep

eate

d L

oa

d F

low

Nu

mb

er

@ 5

4oC

Mix Type and Conditioning Level

Traffic Level

Million

ESALs

Minimum

Flow Number

Cycles

General

Rut

Resistance

< 3 --- Poor to Fair

3 to < 10 53 Good

10 to < 30 190 Very Good

30 740 Excellent


Texas Overlay Tester


Texas Overlay Tester

4134

745

102

6

1

10

100

1000

10000

P601 Logan Airport P601 Logan Airport

STOA LTOA

Overl

ay T

este

r C

ycle

s t

o F

ailu

re @

25

oC

Mix Type and Conditioning Level


Flexural Beam Fatigue

1,000

10,000

100,000

1,000,000

10,000,000

100 1,000

Fati

gu

e L

ife,

Nf,

50%

(Cycle

s)

Tensile Micro-strain (ms)

P601 - STOA

Logan - STOA

P601 - LTOA

Logan - LTOA

32 k

O

k

t

150% f,E

1

ε

1kN


Mix produced in drum plant at 340˚F

Placed at 325˚F without difficulty

Met density specification

Excellent surface appearance

StellarFlex FR at Logan Airport

Fuel-Resistant Usage – New Projects

Boston, MA - Logan Airport Alleyway Project – 2005

Charlotte, NC - Douglas International Airport Runway Project – Summer

2006

Florida DOT Truck Inspection Station –

Summer 2006



Williston, FL – GA Airport Apron project - 2015

Fuel-Resistant Usage – Charlotte

Airport

Charlotte, NC -Douglas International Airport Runway 18L – 36R

August 2006

Night work – Runway available from 11:00 pm until 6:00 am

Mill 2”

Pave with 2” FR Mix

Logan Airport - 2014

De-icing at Logan Airport is done at the gates

Alleyway P-601 pavement in picture has been exposed to de-icing chemicals for 12 winters – no visible damage to date


10 year old P-601 Pavement

Logan Airport – Why did the

Joints Open Up?


10 year old P-601 Pavement

FR at Logan Airport

9 year old StellarFlex FR Pavement


10 Year Old P-401 Pavement with PG 76-28

Logan Airport 2014

10 year old P-601 10 year old P-401

Logan Airport – May 2016

P-601 Pavement from 2004 Still in Place

Logan Airport – June 2017

Runway 4L-22R Repaved with P-401 Mix Containing PG 76-28

Logan Airport – April 2018

One Year Later –Area has been Milled and Replaced

Logan Airport – Runway 4L-22R

Repaved in 2017 with P-401 mix using PG 76-28 binder

Rutted almost immediately

Milled and repaved rutted area in November 2017 with P-601 mix and PG 82-28 FR binder

Fixed problemRunway 4L-22R - August 2014

BWI Airport– Freight Apron Paved in 2015 with

6” P-401 mix base

layers and 2” P-601

surface course

Slight indentations

appeared under

parked air freighters

(B-767, B747)

Forensic analysis

conducted to

identify issue

BWI Airport– Freight Apron It was suggested

that additional compaction of P-601 mix occurred under static load of aircraft

Cored surface layer inside and outside of rutting – no difference in density of any of the cores

Very consistent densities – averaged 3.2% air voids in indentations to 3.1% air voids outside of indentations

BWI Airport– Freight Apron Rutting occurs

either from weak surface layer or weak underlying layers (pavement or subbase)

Straightedge identified no material pushed up around edges of rutting

Indicates problem with underlying layers

BWI Airport– Freight Apron Full depth cores

were cut and binder was extracted from each layer

Surface layer binder was PG 94-22 FR binder meeting P-601 specification

All layers of P-401 mix contained PG 64-22 binder

P-601 GA Project – Williston, FL Airport

P-601 GA Project - Herlong, Florida

Fuel Spill Causes Discoloration, But No Damage to

StellarFlex FR ® Pavement

P-601 for Bus Lanes

Bus lanes have heavy,

channelized traffic –

rutting may be an

issue

Oil and fuel leaks are

also present

Logan Airport has

used P-601 pavement

in bus lanes to solve

the problem

FAA P-601 Specification

FAA was looking for alternative to coal tar sealers – projecting it would be outlawed in near future

Evaluated performance of Logan Airport StellarFlex FR mixes

Adopted Logan Airport FR specification as P-601 “Fuel Resistant Hot Mix Asphalt Pavement” specification in July 2014

P-601 usage is eligible for FAA funding


FAA has adopted

Advisory Circular #

150 / 5370-10G ,

dated 07/21/2014

Contains

specification item

P-601 Fuel

Resistant Hot Mix

Asphalt (HMA)

pavement

FAA P-601 Specification Asphalt Binder Specification

ASTM D6373 Minimum grade of PG 82-22

ASTM D6084 Elastic Recovery at 25°C ≥ 85%

ASTM D7173 Maximum temperature difference of 4°C when using ASTM D36 Ring and Ball apparatus

Mix Specification P-401 ½” mix

Target air voids = 2.5%

50 blow or 50 gyration mix compaction regardless of aircraft type

Maximum Weight loss by fuel immersion 2.5% as measured by test procedure in FAA P-601 Specification Section 601-3.3


FAA has issued

Advisory Circular #

150 / 5370-10H on

December 21, 2018

Renumbers

specification item

P-601 Fuel

Resistant Hot Mix

Asphalt (HMA)

pavement as P-404


Asphalt Binder Specification ASTM D6373 PG 88-22 or PG 82-28 as dictated by

climate

ASTM D6084 Elastic Recovery at 25°C ≥ 85%

ASTM D7173 Maximum temperature difference of 4°C when using ASTM D36 Ring and Ball apparatus

Mix Specification Changes Eliminates natural sand

Allows liquid-anti-strip, if needed

One freeze thaw cycle for TSR test

Adds APA rutting requirement ○ <10mm @ 4000 passes, hose pressure 250 psi

Allowable lift thickness 1.5” – 3”

Maximum Weight Loss Fuel Soak Test = 1.5%

¾” FR Mix Development

Despite demonstrated performance over time, many engineers are uncomfortable with a ½” mix (FAA Mix #3) that is currently in the P-601 specification

They believe a 3/4” FAA Mix #2 gradation is needed to withstand aircraft loadings on taxiways and runways

Associated Asphalt sponsored a research project at Rutgers University to see if a 3/4” FAA Mix #2 could be designed using P-601 criteria (FAA Mix #2 FR) Designed at 2.5% air voids

Designed with 50 Marshall blows

¾” FR Mix Development

Compared ¾” FAA Mix #2 FR version to standard P-401 Mix #2

Compared to P-401 Mix #2 with best asphalt binder available – PG 82-22

Proposed AC 150 5370-10H recommends three grade bumps for heavily trafficked pavements – yields a PG 82-22 in PG 64-22 climate regions

Compared mix performance using multiple laboratory rutting and cracking tests

¾” Fuel Resistant Mix

FAA Gradation #2 Requirements and Research Study Gradation

Specification Lab Design

1 Inch (25.0 mm) --- 100.0

3/4 Inch (19.0 mm) 100 100.0

1/2 Inch (12.5 mm) 90 - 100 92.9

3/8 Inch (9.5 mm) 72 - 88 77.8

No. 4 (4.75 mm) 53 - 73 57.0

No. 8 (2.36 mm) 38 - 60 39.1

No. 16 (1.18 mm) 26 - 48 28.3

No. 30 (600 mm) 18 - 38 19.9

No. 50 (300 mm) 11 - 27 12.1

No. 100 (150 mm) 6 - 8 7.6

No. 200 (75 mm) 3 - 6 4.4

Sieve Size

P401 Gradation 2


Asphalt Binders (true grade)

PG 82-22: PG 83.1-25.3

StellarFlex FR: PG 95.1-25.9


Mix Design Results

Air Voids○ FAA Mix #2 FR = 2.5%

○ P401 FAA Mix #2 = 3.5%

Optimum Asphalt Content○ FAA Mix #2 FR = 6.7%

○ P401 FAA Mix #2 = 5.8%

Voids in Mineral Aggregates (VMA)○ FAA Mix #2 FR = 17.4%

○ P401 FAA Mix #2 = 16.3%

Fuel Resistance Mass Loss○ FAA Mix #2 FR = 0.31%

○ P401 FAA Mix #2 = 5.07%


1,000

10,000

100,000

1,000,000

10,000,000

1.0E-07 1.0E-05 1.0E-03 1.0E-01 1.0E+01 1.0E+03 1.0E+05 1.0E+07

Dy

na

mic

Mo

du

lus

(psi

)


P401 FAA #2 82-22 - STOA

FAA #2 FR - STOA

P601 - STOA

Dynamic Modulus Master Stiffness Curve for Short-Term Oven

Aged (STOA) Asphalt Mixtures


1,000

10,000

100,000

1,000,000

10,000,000

1.0E-07 1.0E-05 1.0E-03 1.0E-01 1.0E+01 1.0E+03 1.0E+05 1.0E+07

Dy

na

mic

Mo

du

lus

(psi

)


P401 FAA #2 82-22 - LTOA

FAA #2 FR - LTOA

P601 - LTOA

Dynamic Modulus Master Stiffness Curve for Long-Term Oven

Aged Asphalt (LTOA) Mixtures


3820

862

7908

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

FAA #2 FR P401 FAA #2 P601

AM

PT

Flo

w N

um

be

r (c

ycle

s)

AMPT Repeated Load Flow Number Results


0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000

AP

A R

utt

ing (

mm

)

Number of Loading Cycles

64oC Test Temp.; 100psi Hose Pressure; 100 lb Load Load

APA Rutting @ 8,000 Cycles

FAA #2 FR = 1.76 mm (Std Dev. = 0.18 mm)

P401 FAA #2 = 2.32 mm (Std Dev. = 0.32 mm)

FAA Proposed APA (100psi/100lb) Criteria ≤ 5 mm Rutting

Asphalt Pavement Analyzer (APA) Rutting Performance


Federal Aviation Administration (FAA) Relationship

Between High Pressure APA vs AASHTO T340 ( Garg, 2017)


Flexural Fatigue Life for FAA #2 FR, P401 FAA #2 and

P-601 Asphalt Mixtures

1,000

10,000

100,000

1,000,000

10,000,000

100 1000

P401 FAA #2 - STOA

P401 FAA #2 - LTOA

FAA #2 FR - STOA

FAA #2 FR - LTOA

P601 - STOA

P601 - LTOA

Beam Fatigue

Cycles to

Failure @ 800

microstrain__

P-401 Mix #2 -

45,000 cycles

FAA Mix #2 FR

– 380,000 cycles

P-601 –

1,000,000 cycles


IDEAL CTIndex Test Results

483.7

294.7

850.9

123.5

37.1

173

0

100

200

300

400

500

600

700

800

900

1000

FAA #2 FR P401 FAA #2 P601 FAA #2 FR P401 FAA #2 P601

STOA LTOA

IDEA

L C

TIn

de

x

Mixture Type and Conditioning

Benefits of FAA P-404 Mix with

StellarFlex FR StellarFlex FR highly polymer modified asphalt

provides: Outstanding rut resistance

Improved fatigue resistance

Resistance to fuel and oil damage – eliminates need for coal tar sealers

Excellent workability (Evotherm is included in formulation)

P-601 mix design has increased asphalt content, which provides: Improved fatigue (cracking) resistance

Increased pavement life (durability)

Combination provides resistance to all potential airfield pavement damages – results in longer pavement life and lower life cycle cost

Questions?

2019 NEC/AAAE Airports Conference Hershey, PA March 28, 2019 830 Coc45_F… · Hershey, PA March...

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