Service technique de laviation civile DGAC/STAC Infrastructure research Current Research Work FAA...

Service technique de l’aviation civile

DGAC/STACInfrastructure research

Current Research Work

FAA Airport Pavement Working Group Atlantic City, NJ 24-26 April, 2011

2Current research workService technique de l’aviation civile25 april 2012

Main research topics

French rational design method for airfield pavements

Materials characterization and testing methods : material exchange FAA <-> DGAC/STAC

Dynamic F/HWD data analysisTowards a rational PCNReliability of friction measurementsWater depth modeling on runways

3Current research workService technique de l’aviation civile25 april 2012

French rational design method for airfield pavements

A new technical manual

A rational method used in France for highway design for more than 30 years

Development of the airfield rational design method from the highway one.

First restricted to new flexible airfield pavement.

4Current research workService technique de l’aviation civile25 april 2012

French rational design method for airfield pavements

2 steps :

−Mechanical design

−Freeze / thaw verification

The mechanical design in 6 steps :

1/ Gathering the data and design parameters (traffic, layers thicknesses, material types and characteristics, risk coefficient…)

5Current research workService technique de l’aviation civile25 april 2012

French rational design method for airfield pavements

2/ Stresses / Strains calculation with an isotropic linear elastic multilayered model

Discretization of the horizontal calculation planes (x,y) located at heights zk using a grid (xi, yj, zk).

x : longitudinal axis of the moving load

y : transverse direction

Calculation planes located at:

the HMA base

(horizontal extensions)

the top of the unbound layers (vertical contractions)

6Current research workService technique de l’aviation civile25 april 2012

French rational design method for airfield pavements

3/ Individual damage calculation without wandering

Deformations induced by the set of moving loads of a landing gear taken into account through the "Miner law continuous integration ":

0

0

X if Xwith X

otherwise

(x) : longitudinal deformation variation

7Current research workService technique de l’aviation civile25 april 2012

French rational design method for airfield pavements

4/ Individual damage calculation with wandering

5/ Cumulated damage calculation

6/ Iterative calculations, setting of the layers’ thickness so that:

- ddcumulated 1 (and lower than 1),

- technological limits regardings materials are satisfied.

8Current research workService technique de l’aviation civile25 april 2012

The technical manual and its software are achieved

Next steps :− trial period by experts to get a feedback

− diffusion to all the users

and further applications : overlay design, rigid pavement design, rational ACN/PCN.

French rational design method for airfield pavements

9Current research workService technique de l’aviation civile25 april 2012

Materials characterization and testing methods

To compare US and French material properties and behaviour

To compare US and French testing methods used for materials characterization

To compare US and French rational design methods

Analysis of NAPTF data to validate/refine this rational design method. The method has been calibrated using the results of two Airbus full-scale testing programs (flexible PEP and HTPT)

10Current research workService technique de l’aviation civile25 april 2012

Materials characterization and testing methods

Materials exchange FAA <-> DGAC/STAC :

French materials received by FAA November 2010:

– Asphalt materials from 1995 facility:

• 101x69x20 cm block (includes surface and base HMA layers).

– Asphalt materials from Bonneuil instrumented facility:

• 63x54x21 cm block (includes surface and base HMA layers).

• 6 HMA cores of varying depth.– Approximately 150 kg of bagged GNT2

(capping layer) from Bonneuil instrumented facility.

• US testing is achieved

11Current research workService technique de l’aviation civile25 april 2012

Materials characterization and testing methods

Materials exchange FAA <-> DGAC/STAC :

U.S. material samples received by STAC April 2011:– (2) Econocrete (lean concrete)

beams, Item P-306, in steel molds.

– (3) Econocrete (lean concrete) cylinders, Item P-306.

– (2) Blocks of asphalt base material, Item P-403.

– (4) Buckets and (1) bag of crushed aggregate base material, Item P-154 (Crushed quarry screenings).

• All materials from NAPTF test items.

• French testing has just been completed

12Current research workService technique de l’aviation civile25 april 2012

Materials characterization and testing methods

And now, in progress :

Comparison and data analysis of the results obtained by FAA and DGAC/STAC

13Current research workService technique de l’aviation civile25 april 2012

French HWD pavement testing methodology (flexible pavements)

A new technical guide for:

1) pavement testing

2) data analysis:-Backcalculation

-Critical strains calculations

-Determination of pavement residual life, and/or bearing capacity (Single Wheel Load, PCN?)

Consistent with the new design guidance

14Current research workService technique de l’aviation civile25 april 2012

Dynamic F/HWD data analysis

Technical guide and associated software (PREDIWARE) almost achieved

Next steps:

− validation by a user committee

− release

Next studies:

− overlay design

− rigid pavement assessment

15Current research workService technique de l’aviation civile25 april 2012

Towards a rational PCN

Study in progress, a new work axis :

The aim is to cross the work done on the rational design method and on the HWD data analysis to develop a method to calculate a rational PCN.

16Current research workService technique de l’aviation civile25 april 2012

Reliability of friction measurements

Aims of the study based on the IMAG device−To identify, quantify and reduce uncertainties

−To be more confident in friction results

First step : Identification of all the parameters affecting the measurements.

17Current research workService technique de l’aviation civile25 april 2012

Reliability of friction measurements

• The main parameters are : Calibration, Tire (wear, pressure), Water depth, Speed, Slip rate, Horizontality of sensors

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

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lity

Calibr

atio

n

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Tire w

ear

Wat

er d

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ire w

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Tire w

ear X

Wat

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epth

Speed

Slip ra

te

Slip ra

te X

Tire

wea

r

Horizo

ntali

ty

95 km/h

65 km/h

40 km/h

18Current research workService technique de l’aviation civile25 april 2012

Reliability of friction measurements

• The results :

– LFC = LFCread 0,10 at 95 km/h

– LFC = LFCread 0,09 at 65 km/h

– LFC = LFCread 0,08 at 40 km/h

• To compare with :

19Current research workService technique de l’aviation civile25 april 2012

Water depth modeling on runways

Modeling of the runway characteristics with the VANI device

−Transverse and longitudinal slopes

−Evenness

−Macro-texture

−Friction (micro-texture)

20Current research workService technique de l’aviation civile25 april 2012

Water depth modeling on runways

Modeling of water flow lines based on VANI data

Development of a software to predict the water depth on the runway during a rainy period or a thunderstorm.

Input data :

-VANI data

-rain intensity (weather data)

Output data :

Water depth

Flow model

21Current research workService technique de l’aviation civile

Thank you

BROUTIN MichaelMichael.broutin@aviation-civile.gouv.frSTAC/IA Infrastructures Aéroportuaires

22Current research workService technique de l’aviation civile25 april 2012

French HWD pavement testing methodology (flexible pavements)

-Use of histories instead of only peak values for backcalculation step

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-Dynamical FE modelling

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