ACCELERATED PAVEMENTACCELERATED PAVEMENT TESTING

ISAP International WorkshopCOLD AND WARM ASPHALT MIXTURE DESIGN/ CHARACTERIZATION AND PAVEMENT DESIGNCHARACTERIZATION AND PAVEMENT DESIGN

FortalezaOctober 5-6, 2009

Dr. Angel MateosCEDEX Transport Research Center

Definition of APT

ALT ~ Accelerated Load Testing (of pavements)APT ~ Accelerated Pavement Testing

C t ll d li ti f t t h l l di t b thControlled application of a prototype wheel loading, at or above the appropriate legal load limit to a prototype or actual, layered, structural pavement system to determine pavement response and performanceunder a controlled, accelerated, accumulation of damage in a compressed time period.

(NCHRP Synthesis 235, 1996)( y , )

Controlled application of wheel loading to pavement structures for the purpose of simulating the effects of long-term in-service loadingpurpose of simulating the effects of long-term in-service loading conditions in a compressed time period.

(NCHRP Synthesis 325, 2004)

Types of Facilities

From laboratory devices......but there are also mobile

to Road Tests...to Road TestsFrom linear Test Tracks......to circular Test Tracks

Most of them are fixed...

Traffic Simulation

Hydraulic ActuatorLINTRACK (N th l d )

Pulse LoadingBASt (G ) LINTRACK (Netherlands)BASt (Germany)

Dead WeightCEDEX (Spain)

Real TrucksWesTrack (USA)

European APT Facilities

PTF (Great Britain)HVS-Nordic (Sweden)LIRA (Romania)Mobile Load Simulator

EMPA-ETH (Switzerland) & BASt (Germany)ETH (Switzerland)LAVOC (Switzerland)PTF (Great Britain)University of Nottingham

HVS-Nordic (Sweden)

PTF (Great Britain)RTM (Denmark)

LINTRACK (Netherlands)( )

BASt (Germany)LAVOC (Switzerland)LCPC (France)

CEDEX (Spain)

European APT Facilities

12

10

8

mbe

r Pulse LoadingLinear Test Track

4

6

Num

Linear Test TrackCircular Test Track

2

01965 1970 1975 1980 1985 1990 1995 2000 2005 2009

Year

Introduction to APTActive APT Programs

in the World (2009)

38 Consolidated Programs5 New Programs

Why APT for WMA ?

Rapid evaluation of pavement performanceth i t d f- months instead of years -

P ti l t tPractical output(loads per month)

most facilities...[100 000 – 400 000]

0 0.5 1 1.5 mill.* *

No risk from failure of in-service pavementsNo risk from failure of in-service pavements

“Almost” real materials in “almost” real pavementsost ea ate a s a ost ea pa e e ts

Why APT for WMA ?

Improved understanding of WMA performance

• Monitored structural response• Monitored structural response

• Systematic evaluation of pavement performanceComputer Simulation /Engineering Judgement

Long Term PavementPerformance Studies

• Detailed knowledge of traffic & environmental conditions FI

T

MH

IGH

Engineering Judgement

Ability to control load & environmental variablesBE

NE

F

ME

DIU

M

Field Testing

Ability to control load & environmental variables

• Load related

LOW

Laboratory Testing

Accelerated PavementTesting

Load related...

• Environment related...COST

LOW MEDIUM HIGH

Potential ApplicationsImplementation in M-E designs methods

• because has to be focused on distress mechanisms• because distresses from in-service pavements...

- are difficult to evaluate- are difficult to evaluate- interact to each other- depends on many input random variables

• because models calibration require structural response inputsbecause models calibration require structural response inputs

Comparative testing• because different WMA production technologies exist• does WMA improve HMA performance?• because different WMA production technologies exist

Climatic considerations• because WMA suitability could depend on climatic conditions• because experiences from 1 site could be extrapolated

• because lab. fundamental tests can be related to short-medium term

Laboratory testing protocol

pavement performance• because a WMA design methodology has to be developed

3rd Intl. Conf. on APT

d / t2008www.cedex.es/apt2008

WMA research referenced at...

- MnROAD mainline 5 sections built in 2008- MnROAD mainline, 5 sections, built in 2008

- University of California (UCPRC), 4 sections, tested in 2007-08

Sargand et al. “Testing of Perpetual Pavement with Warm Asphalt Concrete Surface Mixes in the Ohio APLF”

2 4 ti t t d i 20062x4 sections, tested in 2006

Conclusions

APT can pave the gap from WMA Lab. testing to field performance in in-service pavementsp p

An important APT network exists throughout the world

Th d t i i APT b t tThere are many advantages in using APT, but two strengths must be remarked for WMA:

Improved understanding of WMA performance− Improved understanding of WMA performance− Ability to control load & environmental variables

There are some interesting applications:There are some interesting applications:− Implementation in M-E designs methods− Comparative testingg− Climatic considerations− Laboratory testing protocol

Still l t f ill b iStill, long-term performance will be an issue....

ACCELERATED PAVEMENTACCELERATED PAVEMENT TESTING

ISAP International WorkshopCOLD AND WARM ASPHALT MIXTURE DESIGN/ CHARACTERIZATION AND PAVEMENT DESIGNCHARACTERIZATION AND PAVEMENT DESIGN

FortalezaOctober 5-6, 2009

Dr. Angel MateosCEDEX Transport Research Center

Feasibilities of APT Testing- Monitored Structural Response -

δ Temp.

εMBεVεH

σsuction σV

moistureσH

water table level

Feasibilities of APT Testing- Evaluation of Pavement Performance -

10

11

7

8

9

ties

5

6

7

r of F

acili

t

3

4

5

Num

be

1

2

0BearingCapacity

PermanentDeformation

SurfaceCracking

LongitudinalUnevenness

Texture SkidResistance

SensorsResponse

Source:Survey from 11 Full-Scale European Facilities

Feasibilities of APT Testing- Load-related Variables -

L d l lLoad level

Wheel type (single or dual)

................................... ok

........ ok ...but not d

Tire type

Tire inflation pressure

..................................... ok

k

random distribution

Tire inflation pressure

Transverse position

................. ok

................... ok

Axle type ..................................... ?

Feasibilities of APT Testing- Load-related Variables -

140

120APT Traffic Real Traffic

80

100

d (k

N)

60

xle

Load

20

40

Ax

0

20

11

time

Feasibilities of APT Testing- Load-related Variables -

CEDEX Test Track

± 360 mm

3940

41

3940

41

500

1290 mm

2831

3437

2831

3437 500

passes

Vehicle 1 Track 1 Track 2 Track 3 Track 4 Track 5 Track 6 Track 7

60 mm 60 mm 60 mm 60 mm 60 mm 60 mm

Vehicle 2 Track 1 Track 2 Track 3 Track 4 Track 5 Track 6 Track 7

60 mm 60 mm 60 mm 60 mm 60 mm 60 mm

Feasibilities of APT Testing- Load-related Variables -

Axle Type can be Reproduced in Only a Few

p yTest Tracks

LCPC

ALF

Kansas State Univ.

Feasibilities of APT Testing- Load-related Variables -

100

120

100

80

100Range of Realistic Truck Speed

60 6060

80

d (k

m/h

)

4540

40Spee

d

5 6 811 12 12 12 12 13 13 13 13

1620 20 20 20 21 22 22 22 22 24 25 25

20

5 6

01 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Li T t T k Ci l T t T k

Source: 30 Full-Scale Test Tracks around the world

Linear Test Track Circular Test Track

Feasibilities of APT Testing- Environmental Variables -

Air temperature ................................ ® (always)© (some facilities)

Air moisture .......

© (some facilities)

® (when necessary)

Asphalt temperature ........................® (always)© (some facilities)@ (some facilities)

Water table .......@ (some facilities)

® (when necessary)© (some facilities)®Soils moisture ...

® ( l )

® (always)@ (some facilities)

Rainfall .............

F th© Controlled

® (always)© (some facilities)

©Freeze-thaw ..... @ Indirect Control® Recorded

© (some facilities)

Feasibilities of APT Testing- Environmental Variables

air temperature can pbe controlled in any

indoor facility

LAVOC

FAA BASt

Feasibilities of APT Testing- Environmental Variables

a test pit allowspwater table control

LCPC

and homogeneous... and homogeneous support throughout

tests

CEDEX

Feasibilities of APT Testing- Environmental Variables

some facilities are housed in special climatic chambersclimatic chambers

RTM

... where most environment variables

can be controlled

LAVOC

Temp. 4.4 / 21.1 / 40.0 °C

Wh l L d 40 0 kN t 8 k /h32 mm wearing coursetotal: 400 mm ACWheel Load: 40.0 kN at 8 km/h

(dual wheel)total: 400 mm AC

Temp. 50 / 55 °C

Wh l L d 40 60 kN t 12 k /h120 mm WMA (DGAC)

Wheel Load: 40-60 kN at 12 km/h(dual wheel)