FAA P404 FUEL RESISTANT HOT MIX ASPHALT PAVEMENT

FAA P-404 FUEL RESISTANT HOT MIX ASPHALT PAVEMENT SPECIFICATION 2019 NEC/AAAE Airports Conference Hershey, PA March 28, 2019 Ronald Corun Specialty Products Manager Associated Asphalt Partners, LLC

Background � Airports experience fuel and hydraulic oil spills on aprons and taxiways � Fueling operations � Aircraft sitting in Indentations in Taxiway GG at La. Guardia Airport queues � Softens (weakens) asphalt � Causes permanent deformations and failures

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 7622) 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) appli a pressurized hose (100 psi) whic on top of asphalt samples - Tested at 64 o. C for 8, 000 loading cycles - Computer data acquisition system

Stellar. Flex FR – Rut Resistance APA Rutting, mm 10. 2 12 10 6. 8 8 4. 3 6 1. 6 4 2 0 PG 64 -22 PG 76 -22 PG 82 -22 Stellar. Flex FR

Stellar. Flex 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

Stellar. Flex FR – Crack Resistance 45000 Flexural Beam Fatigue, Cycles to Failure 45000 40000 35000 30000 25000 20000 15000 10000 5000 0 4200 PG 82 -22 Stellar. Flex FR

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 PMA material 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 La. Guardia not rutted

Fuel Resistant Specification � Working with engineers at Mass. Port, 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 4 L 22 R at Logan Airport in June 2004

Stellar. Flex 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 Mass. Port engineers concerned about rutting APA testing at Worcester Polytechnic Institute

Worcester Polytechnic Institute – APA Rut Testing APA Rutting, mm 4. 1 4. 5 4 3. 5 3 2. 5 2 1. 5 1 0. 5 0 3. 6 0. 9 3/4" P-401 Mix 1/2" P-401 Mix 3/4" FR Mix 0. 7 1/2" FR Mix

Logan P-401 vs FR Mix Asphalt Mix Performance Tester (AMPT)

Logan P-401 vs FR Mix AMPT Dynamic Modulus (STOA)

Logan P-401 vs FR Mix AMPT Dynamic Modulus (LTOA)

Logan P-401 vs FR Mix Traffic Level Million ESALs < 3 3 to < 10 10 to < 30 Minimum Flow Number Cycles General Rut Resistance --53 190 740 Poor to Fair Good Very Good Excellent AMPT Flow Number

Logan P-401 vs FR Mix Texas Overlay Tester

Logan P-401 vs FR Mix Texas Overlay Tester

Logan P-401 vs FR Mix Flexural Beam Fatigue

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 �

Stellar. Flex 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 – 2007 � Williston, FL – GA Airport � Apron project - 2015

Fuel-Resistant Usage – Charlotte Airport � Charlotte, NC - Douglas International Airport � Runway 18 L – 36 R � 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 deicing 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 Stellar. Flex 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 4 L-22 R 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 4 L 22 R 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 problem � Runway 4 L-22 R - 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, B 747) � 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 9422 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 Stellar. Flex 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 Stellar. Flex 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 -10 G , dated 07/21/2014 � Contains specification item P -601 Fuel Resistant Hot Mix Asphalt (HMA) pavement �

FAA P-601 Specification � Asphalt Binder Specification �ASTM D 6373 Minimum grade of PG 82 -22 �ASTM D 6084 Elastic Recovery at 25°C ≥ 85% �ASTM D 7173 Maximum temperature difference of 4°C when using ASTM D 36 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 -10 H 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 D 6373 PG 88 -22 or PG 82 -28 as dictated by climate � ASTM D 6084 Elastic Recovery at 25°C ≥ 85% � ASTM D 7173 Maximum temperature difference of 4°C when using ASTM D 36 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 ○ <10 mm @ 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 -10 H 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

¾” Fuel Resistant Mix � Asphalt Binders (true grade) �PG 82 -22: PG 83. 1 -25. 3 �Stellar. Flex FR: PG 95. 1 -25. 9

¾” Fuel Resistant Mix � Mix Design Results �Air Voids ○ FAA Mix #2 FR = 2. 5% ○ P 401 FAA Mix #2 = 3. 5% �Optimum Asphalt Content ○ FAA Mix #2 FR = 6. 7% ○ P 401 FAA Mix #2 = 5. 8% �Voids in Mineral Aggregates (VMA) ○ FAA Mix #2 FR = 17. 4% ○ P 401 FAA Mix #2 = 16. 3% �Fuel Resistance Mass Loss ○ FAA Mix #2 FR = 0. 31% ○ P 401 FAA Mix #2 = 5. 07%

¾” Fuel Resistant Mix Dynamic Modulus Master Stiffness Curve for Short-Term Oven Aged (STOA) Asphalt Mixtures

¾” Fuel Resistant Mix Dynamic Modulus Master Stiffness Curve for Long-Term Oven Aged Asphalt (LTOA) Mixtures

¾” Fuel Resistant Mix AMPT Repeated Load Flow Number Results

¾” Fuel Resistant Mix Asphalt Pavement Analyzer (APA) Rutting Performance

¾” Fuel Resistant Mix Federal Aviation Administration (FAA) Relationship Between High Pressure APA vs AASHTO T 340 ( Garg, 2017)

¾” Fuel Resistant Mix 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 cycles Flexural Fatigue Life for FAA #2 FR, P 401 FAA #2 and P-601 Asphalt Mixtures

¾” Fuel Resistant Mix IDEAL CTIndex Test Results

Benefits of FAA P-404 Mix with Stellar. Flex FR � Stellar. Flex 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

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