Use of Public RoadsUse of Public Roads New perspectives in mixture New perspectives in mixture

designingdesigningRole of the state in Technological Role of the state in Technological

DevelopmentsDevelopments

Chantal de La ROCHELCPC - France

Head of Road and binders materials section

Performance-based Road Construction TechnologyTerms of Reference, Contract, Conditions

Conference of Hungarian Road Society - 16-17 Nov 2005

OutlinesOutlines

French road networks : some figures

An example of performance based mix design methodology

Trends in bituminous mixture evolution

Role of the state in technological development

Conclusion and future prospects.

Superficies 550 000 km²Population : 63 Millions1 million kms of roads

Overview of the French Road NatworkOverview of the French Road Natwork

Notional Roads 20 000 km

Toll Motorways 8 000 km

Free motorways 3 000 km

Routes de liaisons 8 800 km

Departments 380 000 km

Cities 600 000 km

French Roads : some figuresFrench Roads : some figures

Réseau routier français

RoutesCommunales

58%

RoutesDépartementales

38%

Autoroutes1%

Routes Nationales

3%

1 Million de km en linéaire

7500 kms 28000kms

550000 kms

365000 kms

Transfer to local authorities 1/1/2006 : RN 12 000 kms

Temperate climate θ surface -15°C, + 60°C, average 15°C

Average traffic: 20 à 60 000 v/j

French Roads : some figuresFrench Roads : some figures

Remark: legal axle load 130 kN

Autoroutes68%

R. Nationales

28%

Routes Communales

0%

RoutesDépartementales

4%

REPARTITION DES TRAFICS

22 800 V/j

9 400 V/j

1 300 V/j 150 V/j

An example of performance based An example of performance based methodologymethodology

French Bituminous French Bituminous Mix Design MethodologyMix Design Methodology

One material type for each needOne material type for each need

Optimized with performance based Optimized with performance based criteriacriteria

In relation with its use on the roadIn relation with its use on the road

Principle Principle

Standard Performances Lab study Gradation & Binder content designer’s

choice

Typical grading curves

0

10

20

30

40

50

60

70

80

90

100

0.1 1 10

Sieve [mm]

Paa

sing

[%

]

ECF

BBSG

BBM

BBTM

BBUM

BBDr

Formulation tool: Gyratory

Compactor(PCG)

Mix design Mix design and Compositionand Composition

Mix design Formulation methodMix design Formulation method

Components selection(aggregates, filler, binder, additives)

Check of their properties performance class

Minimum binder content defined by standard K Richness modulus (linked to the binder

film thickness) Level of mix design study

defined in contract Check of the performance versus the selected

class of the product standard

Performances tested Performances tested

One test per property Gyratory compactor (PCG)

workability and compactability assessment

Immersion compression (Duriez) test Water sensitivity

Wheel tracking test Rutting resistance

Direct tensile or 2 point bending test Stiffness

2 points bending test Fatigue resistance

Design stepsDesign steps

Selection and identification of components

Choice: gradation & binder content

Compactability test (gyratory)

Duriez test

Rutting test

Modulus test

Fatigue test

Formulation selected

Level 1

Level 2

Level 3

Level 4

Compaction

Water sensitivity

Rutting

Stiffness

Fatigue

Level 1 and 2 testsLevel 1 and 2 tests

Components selection(aggregates, filler, binder, additives)

Check of their properties performance class

Manufacturing and control of samples Gyratory compaction test Water sensitivity Wheel tracking rutting test Marshall

Marshall test

Preparation of samples in laboratoryPreparation of samples in laboratory

Good control quality of mix: composition, voids,.. Homogeneity

Accurate and Relevant Tests Relevant comparison with in situ materials

Mixer BBMAX 80

Plate compactor: 400*600*150 or 180*500*25 à 100

Vertical gamma Bench

EN 12697-33EN 12697-33

ex NFP 98-250-2ex NFP 98-250-2

EN 12697-35 ex NFP 98-250-1) (EN 12697-7 ex NFP 98-250-5)(EN 12697-7 ex NFP 98-250-5)

MLPC Gyratory shear compactor

Gyratory compactor Standard (NF 12697-31

ex NFP 98-252) Characterisation of void %

reduction under axial force + gyratory shear

Mix design by adjustment of void content according to product standards

Estimation of site void contentVsite = V(Ne)

Ne nbr of cycle as thickness [mm]

r = 0,95 R = 1,38 (% voids 60 g)

Compactability characterisationCompactability characterisation

Repetability 0,95Reproducibility 1,34

Typical resultV

oid

cont

ent (

%)

Void content

Failed

Failed

InterpretationInterpretationof gyratory compaction testof gyratory compaction test

Conformity study of a mix in relation to product standard specification for each material type ( NFP 98-130 to 141)

Pass

% voids

Number of passes2 26168

20

10

5

4

6

812 cm

Void content versus layer thicknessVoid content versus layer thicknessIn site compaction processIn site compaction process

0

2

4

6

8

10

12

14

BB

AC

BB

AC

(bin

der

)

BB

AG

G

BB

ME

GB

2

GB

3

EM

E 1

EM

E 2

Vo

ids

%

On spec

Out of spec

Gyratory compactor test: Gyratory compactor test: specificationsspecifications

Gyratory compactor test: Gyratory compactor test: specificationsspecifications

Water sensitivity : Duriez testWater sensitivity : Duriez test

Standard NFP 98-251-1 Two compaction efforts: D< 14 mm H 190 mm, 60 kN, 5

min D>14 mm H 270 mm, 180 kN, 5

min Stored at 18 °C, 7 days

in air (50 % moisture) in water

Vertical compression (1 mm/s ) Ratio r/R (and % voids) Repeatability and reproducibility

r = 0,08 R =0,13 (ratio of 0,73) Decision to use of an adhesion agent

European standard indirect tensile test (EN 12697-12)

Level 2 : rutting resistance testLevel 2 : rutting resistance test

LPC Wheel tracking testLPC Wheel tracking test

Wheel

Rut depth measurement

Standard (EN 12697-22 ex NFP 98-253-1

Influence of heavy, slow, channelled traffic under high temperature

relevant correlation with site, repeatability (r = 1,2 et R =1,3)

Test conditions: Smooth tire, pressure 0.6

MPa Load 5 kN, speed 1 cycle/s Controlled temperature

60°C

LPC Wheel tracking testLPC Wheel tracking testLPC Wheel tracking testLPC Wheel tracking test

Rutting

Number of cycles

AverageRegression

Typical results with the LCPC wheel Typical results with the LCPC wheel tracking tracking

Influence of binder contentInfluence of binder contentInfluence of binder contentInfluence of binder content

Influence of binder typeInfluence of binder type

Influence of sand natureInfluence of sand natureInfluence of sand natureInfluence of sand nature

Influence of aggregates shapeInfluence of aggregates shapeInfluence of aggregates shapeInfluence of aggregates shape

Influence of void contentInfluence of void content

Rutting resistance -specificationsRutting resistance -specificationsRutting resistance -specificationsRutting resistance -specifications

Test @ 60 °C

0

4

8

12

16

20

BBA1

BBA2

BBA3

BBME1

BBME2

BBME3

GB 2to 4

EME1-2

Ru

t d

epth

[%

]

Surface Base

Number of cycles 10 000 30 000 10 000 30 000

Out of spec

On spec

Level 3 and 4Level 3 and 4

Mechanical tests:stiffness measurement (direct tensile test or 2 points

bending on trapezoidal samples)Fatigue resistance test

Determination of bituminous mixes Determination of bituminous mixes mechanical characteristics for pavement mechanical characteristics for pavement

structural designstructural design

Need for stiffness characteristics and fatigue resistance : admissible strain for 1 million cycles

Traffic direction

Wearing course

Base

Sub-base

Natural soil

BituminousLayers Thickness tStiffness E(tension)

Non treated

Direct tensile test

100

1000

10000

100000

0,0001 0,01 1 100 10000

Temps (s)

Mod

ule

(Mpa

)

0°C

10 °C

15°C

courbemaîtresseSérie4

Série6

EN 12697-26 ex NFP 98 260-1

Direct tension on cylindrical specimen

Master curve (rheological behavior)

Modulus for pavement design (specification) 15°C, 0,02s

Complex modulus testComplex modulus test

EN 12697-26 ex NFP 98 260-2 2 points bending on trapezoidal samples, 4 repetitions

E pavement design 15°C, 10 Hz Master curve (rheological behavior)

60°C

100

1000

10000

100000

0,1 1,0 10,0 100,0

Fréquence (Hz)

-10°C0°C10°C15°C20°C30°C40°C

r = 335 MPa , R = 2750 MPa (E = 15300 MPa)

StiffnessStiffnessStiffnessStiffness

Modulus @ 15°C: complex (10 Hz) or tensile (0,02 s)

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

BBA1-2

BBA3

BBME1

BBME2-3

GB 2-3

GB 4 EME1-2

Mo

du

lus

[M

Pa]

Out of spec

On spec

Fatigue testFatigue test

Standard EN 12697-24 ex NF P 98-261-1 2 points Bending beam on trapezoidal samples

B=56, b=25, t=2, h=250 mm 3 strain levels with 6 specimens each, 10°C and 25 Hz Strain calculated for 1 million of cycles 6

(better behavior for high 6) r = 4,2 µstrain R= 8,3 µstrain

Droite de fatigue

1000

10000

100000

1000000

10000000

10 100 1000

Déformation

Nombre

de cy

cles

6

Fatigue testFatigue testFatigue testFatigue test

Admissible strain @ 10 °C and 25 Hz [µstrain]

70

80

90

100

110

120

130

140

150

BBA 1 BBA 2 BBA 3 BBME1

BBME2-3

GB 2 GB 3 GB 4 EME1

EME2

[

µst

rain

]

Out of spec

On spec

level1level1Giratory, water sensitivity

Level 2Level 2Level 2Level 2

Level 3Level 3

Level 4Level 4

Permanent deformation

Stiffness

Fatigue

Summary of the French mix design Summary of the French mix design methodologymethodology

Trends in bituminous mixtures evolutionsTrends in bituminous mixtures evolutions

Dissociation of layer functionsDissociation of layer functions : : base = structure base = structure

wearing course = surface caracteristics.wearing course = surface caracteristics.

Trends in bituminous mixtures evolutionsTrends in bituminous mixtures evolutions

Dissociation of layer functionsDissociation of layer functions : : base = structure base = structure

wearing course = surface caracteristics.wearing course = surface caracteristics.

Base materials evolutionBase materials evolution

Higher and higher binder contents

Smaller aggregate maximum size : 31 20 14 10 mm

Increase of bitumen hardness: 50 35 20 10 pen

Additives to increase hardness

Performances improvement GB 3 then GB 4

EME 2

Reduction of thicknesses

Base and foundation materials Base and foundation materials evolutionevolution

0

20

40

60

80

100

120

140

1970 1980 1990 2000 EME

% bitume

Grade

Module

Typ

e of

mix

Gir

ator

y. (

Voi

ds %

)C

80 (

D 1

0mm

)C

100

(D 1

4mm

) C

120

(D 2

0 m

m)

Wat

er s

ensi

tivi

tyr/

R r

atio

Rut

dep

th(6

0°C

-100

mm

)*

10.0

00 c

ycle

s (%

)**

30.

000

cycl

es (

%)

Stif

fnes

s m

odul

us(1

5°C

-10H

z) in

MP

a

Fat

igue

– a

dmis

sibl

e st

rain

(@ 1

mil

lion

de c

ycle

s)

G.BClass 2

11 0.65 10* 9,000 80.10-6

GBClass 3

10 0.7 10* 9,000 90.10-6

GBClass 4

9 0.7 10** 11,000 100.10-6

EMEClass 1

10 0.7 7.5** 14,000 100.10-6

EMEclass 2

6 0.75 7.5** 14,000 130.10-6

Base Hot Mix Asphalt : main Base Hot Mix Asphalt : main performances performances

surface materials evolutionsurface materials evolution

Thinner and thinner layers 1 to 2cm

Gap graded curves

Increase of porosity

Need for water proofing tack coat

More and more use of modified and special

binders

Standardized products performance

characteristics

Role of the state in Technological Role of the state in Technological DevelopmentsDevelopments

Existing toolsExisting tools

Common researches between French administration and road contractors

development of products, methodologies, laboratory devices, techniques, technical guides

Standardization French since 1992 10 product standards European with typical French products such as

BBTM taken into account

Innovation policy of the French administration example : innovation protocol (charte de l’innovation)

Innovation policyInnovation policy

For more than 25 years

Strong input of French administration:

Innovative Techniques Concourse Technical advices (avis techniques) Innovation protocol (charte de l’innovation)

Innovation policy - examplesInnovation policy - examples

Innovation protocols(chartes de l’innovation)

French Road administration/road contractorsFrench Road administration/toll motorway companies

Technical conventions SETRA / Departments

Innovation protocol : mean Innovation protocol : mean featuresfeatures

Focus on some priority subjects Partnership Sharing of observation data Financial risk acceptation : French Road

administration pays for over cost and possible repairs

Common conclusion Leading committee Technical validation : Certificate

Innovation protocol : OrganisationInnovation protocol : Organisation

SUBJECTSPROPOSALS

SELECTION EXPERIMENTATIONSSURVEYS

CONCLUSIONS - DECISION

CERTIFICATE

AGREMENT PROTOCOL

Some studied subjects among the Some studied subjects among the various innovation protocolsvarious innovation protocols

Preventing permanent deformation Preventing reflective cracking Bituminous mixtures recycling Improvement of surface characteristics Recycling porous asphalts Cleanliness of tack coats…..

Conclusion after 10 years (French Conclusion after 10 years (French Road administration - road Road administration - road

contractors) contractors)

79 agreement protocols 189 innovative sites 60 French departments All the French road contactors 24 certificates 10 Millions €uros (over costs) Survey by the Regional Laboratories of

Ponts et Chaussées

ConclusionsConclusions

French mix design methodology is based on the following performances : Workability assessment (Giratory, central tool) Water sensitivity Resistance to permanent deformation Stiffness Fatiguedepending on the mix design study level asked in

contractual documents Performances based mix design methodology

allows Optimization of mix design to the expected use of the

material Evolution of techniques Innovation

ConclusionsConclusions

Technological development requires Strong administration policy Partnership of all the road community

I whish you a very fruitful meeting on I whish you a very fruitful meeting on performance based Road construction technologyperformance based Road construction technology

Thank you for your attention !Thank you for your attention !

Kõszõnõm a figyelmúket !