2019 nec/aaae airports conference hershey, pa … 830 coc45...2019/03/28 · august 2002 graded as...
TRANSCRIPT
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
Fuel-Resistant PMA Usage – La Guardia
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
Fuel-Resistant PMA Usage – La Guardia
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
Fuel-Resistant Usage – 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
Fuel-Resistant Usage – 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)
Logan P-401 vs FR Mix
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
Logan P-401 vs FR Mix
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
)
Loading Frequency (Hz)
P601 - LTOA
Logan Airport - LTOA
Logan P-401 vs FR Mix
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
Logan P-401 vs FR Mix
Texas Overlay Tester
Logan P-401 vs FR Mix
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
Logan P-401 vs FR Mix
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
Fuel-Resistant Usage – Logan Airport
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
Boston, MA - Logan Airport Alleyway Project – 2006
Boston, MA - Logan Airport Alleyway Project – 2007
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
Fuel-Resistant Usage – Logan Airport
Fuel-Resistant Usage – Logan Airport
Fuel-Resistant Usage – Logan Airport
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
Logan Airport - 2014
10 year old P-601 Pavement
Logan Airport - 2014
10 year old P-601 Pavement
Logan Airport – Why did the
Joints Open Up?
Logan Airport - 2014
10 year old P-601 Pavement
FR at Logan Airport
9 year old StellarFlex FR Pavement
Logan Airport - 2014
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 P-601 Specification
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 P-404 Specification
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
FAA P-404 Specification
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
¾” Fuel Resistant Mix
Asphalt Binders (true grade)
PG 82-22: PG 83.1-25.3
StellarFlex FR: PG 95.1-25.9
¾” Fuel Resistant Mix
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%
¾” Fuel Resistant Mix
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)
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
¾” Fuel Resistant Mix
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)
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
¾” Fuel Resistant Mix
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
¾” Fuel Resistant Mix
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
¾” Fuel Resistant Mix
Federal Aviation Administration (FAA) Relationship
Between High Pressure APA vs AASHTO T340 ( Garg, 2017)
¾” Fuel Resistant Mix
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
¾” Fuel Resistant Mix
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?