7/28/2019 07 Airport Pavt Design[1]
1/32
By laurent Porot
Technology Implementer,Shell Bitumen Sustainable development
Airport Pavement Design
Airport Workshop Lafarge/Shell
10th July 2007, London
7/28/2019 07 Airport Pavt Design[1]
2/32
2
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desig
Agenda
1. Background2. What are the key parameters for airport pavements
3. What about pavement design
4. What is new in airport pavement engineering
5. Conclusions
7/28/2019 07 Airport Pavt Design[1]
3/32
3
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desig
1. Background
2. What are the key parameters for airport pavements?
3. What about pavement design?4. What is new in airport pavement engineering?
5. Conclusions
7/28/2019 07 Airport Pavt Design[1]
4/32
4
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desig
A road can fail a runway can not
Airport pavements must exhibit higher performances than roadpavements and are less tolerant of failures
Which properties should be optimised
What is the reality
7/28/2019 07 Airport Pavt Design[1]
5/32
5
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Airport pavement specificity
Airport pavement is not as unique as a road!
Apron
Runway
Taxiway
Terminal
7/28/2019 07 Airport Pavt Design[1]
6/32
6
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Airport vs. Road
In terms of geometry
Wider, shorter length and low transversal slope
In terms of loadings
Higher load up to 16bars, up to 6 wheels
Low speed on taxiways, high speed on runways
In terms of pavementLower traffic volume 104 instead of 106 cycles
Random in loading application
In terms of serviceability
Skid resistance
FOD
Traffic control
7/28/2019 07 Airport Pavt Design[1]
7/32
7
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
1. Background
2. What are the key parameters for airport pavements?
3. What about pavement design?
4. What is new in airport pavement engineering?
5. Conclusions
7/28/2019 07 Airport Pavt Design[1]
8/32
8
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Airport pavement functions
Granular base layers
Bound base layers
Top layers
Asset value:Structural need
Cracking
Permanent deformation
Maintenance:Rubber removal
Surface sealantDe-icing
Works under traffic control
Overlay on concrete
Service value:Permanent deformation
Surface ShearSkid resistance
Water evacuation
FOD / integrity
Fuel spilling
Joint sealant
7/28/2019 07 Airport Pavt Design[1]
9/32
9
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Airport pavement functions
Granular base layers
Bound base layers
Top layers
Asset value:Structural needCrackingPermanent deformation
Maintenance:Rubber removal
Surface sealantDe-icing
Works under traffic control
Overlay on concrete
Service value:Permanent deformationSurface ShearSkid resistance
Water evacuation
FOD / integrity
Fuel spillingJoint sealant
7/28/2019 07 Airport Pavt Design[1]
10/32
10
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Permanent deformation
Degradation on aprons, taxiways, runway entrances
Mainly at aircraft stop lines
Material performances:
Static loading more than dynamic loading
Stiffness at low speed (low frequency)
Low energy dissipation
Suitable solution
Thin asphalt system for top layers (SMA)
High modulus base layer
Polymer modified bitumen PmB
7/28/2019 07 Airport Pavt Design[1]
11/32
7/28/2019 07 Airport Pavt Design[1]
12/32
12
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Strength and structural need
Structural value of the pavement itself
Spread load on sub grade and withstand traffic flow
Valid on aprons, taxiways, runways
Material performance
Stiffness at various conditions
7/28/2019 07 Airport Pavt Design[1]
13/32
13
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Strength and structural need
Structural value of the pavement itself
Spread load on sub grade and withstand traffic flow
Valid on aprons, taxiways, runways
Material performance
Stiffness at various conditions
Master Curve at 15C
100
1000
10000
100000
1,E-03 1,E-02 1,E-01 1,E+00 1,E+01 1,E+02 1,E+03 1,E+04 1,E+05 1,E+06
Shift Frequency
Modulus,
MPa
Asphalt Mix A
Asphalt Mix B
Asphalt Mix C
15C 10Hz
High T
Low frequencyLow T
High frequency
7/28/2019 07 Airport Pavt Design[1]
14/32
14
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Master Curve at 15C
100
1000
10000
100000
1,E-03 1,E-02 1,E-01 1,E+00 1,E+01 1,E+02 1,E+03 1,E+04 1,E+05 1,E+06
Shift Frequency
Modulus,MPa
Asphalt Mix A
Asphalt Mix B
Asphalt Mix C
15C 10Hz
High T
Low frequencyLow T
High frequency
Strength and structural need
Structural value of the pavement itself
Spread load on sub grade and withstand traffic flow
Valid on aprons, taxiways, runways
Material performance
Stiffness at various conditions
Dense asphalt concrete
Depends on the load conditions
7/28/2019 07 Airport Pavt Design[1]
15/32
15
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Fuel resistance
Degradation on taxiways, aprons
Due to chemical agent
Can lead to integrity loss FOD
Material performance required:
Fuel resistance
Dense asphalt / closed surface
Special products available
Fuel resisting binder instead of tar
7/28/2019 07 Airport Pavt Design[1]
16/32
16
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Airport pavements are specific
Pavement materials have to address key performance parameters
How to predict and characterise these performances
Relevant testing
Under which conditions
7/28/2019 07 Airport Pavt Design[1]
17/32
17
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Specification for permanent deformation
For road applications
Wheel tracking test
Dynamic loading
Standard road loading
Creep test static or cyclic
What is suitable for airport applicationsStatic loading
Slow speed related (loading time)
Heavy load, high pressure
French Wheel Tracking Tester
Creep test
7/28/2019 07 Airport Pavt Design[1]
18/32
18
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Specification for cracking resistance
For road applications
Fatigue test
For 1 million cycles
Strain level in range of 60-150 micro strain
Thermal cracking susceptibility
What is suitable for airport applicationsFatigue test
For 10 000 cycles
High strain level in connection with heavy load
Healing effect
Fracture toughness
Fracture toughness
2 points fatigue test
7/28/2019 07 Airport Pavt Design[1]
19/32
19
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Strength and structural need
For road applications
Elastic modulus (at low strain level)
Indirect tensile strength, ITS at 20C
Full complex modulus measurement
What is suitable for airport applications
High strain maybe not any more in the elastic domain
Need for complex modulus measurement and interpretation
At various conditions especially for slow speed
Look at visco-elasticity of the material
7/28/2019 07 Airport Pavt Design[1]
20/32
20
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Fuel resisting material
Common fuel immersion test procedure
Immersion of samples in kerosene
Results compared to dry samples
Mass loss
As a function of immersion time
Less than 1% after 24h
Specimen stability after immersion
Indirect Tensile Strength
Limited use, depend on integrity of specimen
Direct compression StrengthNot less than 75% of strength loss
Specimen mass loss as a function of Kerosine Immersion Time
BBSG 0/10, 5% voids
0
2
4
6
8
10
12
14
16
18
0 20 40 60 80 100 120 140 160 18
Immersion time, h
Specimenmassloss,%
7/28/2019 07 Airport Pavt Design[1]
21/32
21
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
1. Background
2. What are the key parameters for airport pavements?
3. What about pavement design?
4. What is new in airport pavement engineering?
5. Conclusions
7/28/2019 07 Airport Pavt Design[1]
22/32
22
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Current approach - ACN/PCN Principle
International system set up by ICAO in Annex 14
ACN/PCN approach
Aircraft Classification Number, ACN
Maximum mass, quality of the soil support, type of structure
Pavement Classification Number, PCN
Comparison of ACN to PCN
The CBR (Californian Bearing Ratio) method
Empirical approach using a simple equivalent wheel
Pavement thickness equivalence & layer equivalency factor per material
Limitation
Based on DC10 as the heaviest aircraft (in correlation with the AASHO road test)
Empirical method based on CBR and material equivalency
Does not take into account material performances
7/28/2019 07 Airport Pavt Design[1]
23/32
23
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Effect of super jumbo jets
Introduction of large body aircraft
Bogies of 4 wheels, up to 6 wheels
Aggressiveness of B777, B747, A340, A380
Much higher than small body aircraft
Research program has shown new
pavement failure from bituminous layers
7/28/2019 07 Airport Pavt Design[1]
24/32
24
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
The new FAA method
FAA has developed a Layered Elastic airport pavement Design (LEDFAA) to comply with large aircraft
body(software available for free)
Bases on multilayered model similar to Shells BISAR
Input
Real traffic flow and load configuration
Elastic modulus of material
Still limitations
Does not take into accountclimate condition (fatigue law)
7/28/2019 07 Airport Pavt Design[1]
25/32
25
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Other approaches
Aircraft Loading Index ALI approach
3D Finite Element method
Research & Experiments
National Airport Pavement Test Facility, NAPTF (Atlantic City, US)
Pavement Experimental Programme, PEP (LCPC-Airbus)
7/28/2019 07 Airport Pavt Design[1]
26/32
26
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
1. Background
2. What are the key parameters for airport pavements?
3. What about pavement design?
4. What is new in airport pavement engineering?
5. Conclusions
7/28/2019 07 Airport Pavt Design[1]
27/32
27
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Experience sharing FAA (US)
FAA recommendation for bitumen selection (AC 150-5370-10B P401)
Use of the PG grade framework as a reference
In range of PG58 and PG76 for surface layers
PG bump regarding traffic classes for runway, taxiway/Aprons
FAA recommendation for asphalt mix design
Shift from Marshal method to Superpave method
Use of Superpave Gyratory Compactor with Ndesign and Nmax
Some on going research for more fundamental specifications
Fuel resistance sealer and binder (research project 05-02)
Use of Stone Matrix Asphalt SMA (research project 04-04)
Energy ratio approach for assessing fatigue performance at high strain levels (University of Illinois researchpartnership)
7/28/2019 07 Airport Pavt Design[1]
28/32
28
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Experience sharing Middle East
Characterisation of permanent deformation
resistance
Model Mobile Load Simulator MMLS from South Africa
Adaptation of the speed and cycle number for airfieldapplication
Introduction of PG82
Greater high temperature criteria to better fit with hot dry climate
7/28/2019 07 Airport Pavt Design[1]
29/32
29
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Experience sharing Europe
Airbus research programme
Pavement Experimental Programme 1&2 1998-2003 to assess impact of A380 on pavement (PEP1 bituminouspavement, PEP2 rigid pavement)
Simulation of pavement strain/stress distribution
Cracking performances
PEP 3 to start in 2007 to assess the tyre pressure effect on permanent deformation of asphalt pavement
7 asphalt mixtures to be assessed under various conditions of loading
French BBA, a dedicated asphalt mixture for Airfield application
Gap graded asphalt mixture
Special specification against fatigue cracking and permanent deformation
7/28/2019 07 Airport Pavt Design[1]
30/32
30
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
1. Introduction
2. Airport pavement similar to road pavement?
3. What are the key parameters for airport?
4. What about specification?
5. Conclusions
7/28/2019 07 Airport Pavt Design[1]
31/32
31
Airport Workshop Lafarge/Shell, 10th of July 2007 Londo
Airport Pavement Desi
Conclusions
A road can fail a runway can not Airport pavements are different than road pavements
Function, loading, use, operation
Key parameters for airport pavement have greater impact
Static loading
High strain and stress levels
Extreme conditions
Road specifications might be not adapted to suit airfield application
Need for specific dedicated pavement engineering
7/28/2019 07 Airport Pavt Design[1]
32/32
Airport Pavement Design
Airport Workshop Lafarge/Shell
10th July 2007, London