non-destructive pavement testing atconferences.illinois.edu/the/webpdf/rowden.pdf · 2004-04-15 ·...

Non-DestructivePavement Testing atIDOT

LaDonna R. Rowden, P.E.Pavement Technology Engineer

Bureau of Materials and Physical Research

Physical Research Section

BridgeInvestigations

Unit

PavementTechnology

Unit

ProductsEvaluation

Unit

TechnicalServices

Unit

OperationsSub-Unit

Pavement DataManagement

Sub-Unit

Types of Testing

Pavement Surface Distress andRiding Quality

Skid Resistance (Pavement Friction)

Falling Weight Deflectometer (FWD)

Pavement Surface Distressand Riding Quality

Pavement Surface Distress

Six cameras record images from theroadway– Three front-facing perspective– One rear-facing– Two pairs of down-facing (only one set

collects at a time)

Images collected at a rate of 3 to 1,downward to perspective

International Roughness Index– Measurement relating how passengers

perceive the roughness of the pavement.– Pavement Profile analyzed using a

quarter-car simulation.– Collected in each wheelpath using lasers.– Recorded in inches/mile (mm/km).

Pavement Riding Quality

International RoughnessIndex (IRI)

Over 320Rough

191 to 320Medium

0 to 190Smooth

VALUERATING

Subjective Ratings for All Countries

Pavement Riding Quality

Rut Depth– Permanent deformation of the pavement

surface due to wheel loads.– Collected through lasers in each

wheelpath.– Recorded in inches (mm).

Pavement Riding Quality

RWP LWPCEN

LWGRWGRWG LWG

RWP CEN LWP

Calculations:Left Rut Depth: LWP-(CEN+LWG)/2Right Rut Depth: RWP-(CEN+RWG)/2Center Rut Depth: (RWP+LWP)/2-CEN

Pavement Surface Distressand Riding Quality

Information stored in a database.IDOT has 15 workstations forreviewing images and data.Select 5 predominant distresses.CRS value determined from distressesand ride quality data.

Pavement Inventory

Interstates Tested Annually

Non-Interstates Tested Biannually– Even Years: 1 (Cook Co.), 4, 5, 8, 9– Odd Years: 1 (Collar Co.), 2, 3, 6, 7

Special Requests

SKIDRESISTANCE

(Pavement Friction) Slippery

when

wet

Sharon HaasisBureau of Materials & Physical Research

SKID TRAILER

FRICTION NUMBER (FN)

• Represents the frictional properties of thepavement.

• Used to evaluate skid resistance of thepavement relative to other pavements.

• Used to evaluate the change in skid resistance of the pavement with time.

• FNt represents treaded tire measurements.

• FNs represents smooth tire measurements.

• Treaded tire measures microtexture of pavement.

• Smooth tire measures macrotexture of pavement.

FNt and FNs

• Microtexture– Irregularities of aggregate surface

– Measured by Treaded Tire

• Macrotexture– Drainage paths between aggregate

particles

– Measured by Smooth Tire

PAVEMENT PROPERTIES

• Standard Test Method for SkidResistance of Paved Surfaces Using aFull-Scale Tire– Test Speed of 40 mph

– Water sprayed under tire

– Brake applied

– Torque on axle recorded

– Friction Number calculated

ASTM E274

• HA - wet weather accident locations.

• NC - new construction and pavement rehabilitation sites.

• RR - reruns of the new construction jobs.

• MS - Miscellaneous test requests (Unknown construction contract numbers and special request jobs).

TESTING CATEGORIES

• Surface Course Age

• Traffic

• Seasonal Changes

• Speed

INFLUENCES

REASONS FOR FRICTION TESTING

• Evaluate Mixture Performance– Bituminous Mixture type determined by ADT level

• Mixture C: 0 – 5,000

• Mixture D: 5,001 – 25,000 (4-lane)5,001 – 60,000 (6-lane)

• Mixture E: 25,001 – 100,000 (4-lane)60,001 – 100,000 (6-lane)

• Mixture F: > 100,000

– PCC texture determined by speed limit• Type A Finish: > 40 mph

• Type A or B Finish: ≤ 40 mph

CATEGORICAL RATING GUIDELINES

FNt < 30 or

FNs < 15

Friction may be a factorcontributing to wetweather accidents

Contact:

Sharon Haasis, Research EngineerBureau of Materials & Physical Research

217-782-0551haasissl@nt.dot.state.il.us

Or

LaDonna Rowden Pavement Technology Engineer

Bureau of Materials & Physical Research217-782-8582

rowdenlr@nt.dot.state.il.us

QUESTIONS ?

Falling WeightDeflectometer (FWD)Testing at IDOT

Charles J. Wienrank, P.E.Pavement Analysis Engineer

What is an FWD?

Impulse loading device used forstructural evaluation of pavements.– Load is applied to pavement that

simulates truck or aircraft wheel loads.– Resulting deflections are measured using

a series of velocity transducers.– Deflection data used to analyze pavement

structure.

Deflection Basin

Advantages of FWD

Accurately models a moving wheel load.Does not damage pavement.Testing can be done rapidly and at alower cost than destructive testing.– 50 to 60 tests done per hour.– Less disruptive to traffic than destructive

testing.

Flexible Pavements

Determine structural adequacy of pavement.Determine uniformity of support along a projectand identify weak areas.Estimate subgrade and pavement layer elasticmoduli values.Determine overlay thickness requirements.Develop cost-effective maintenance andrehabilitation alternatives.

Sample Deflection Profile

05

10152025303540

0+00

6+00

12+00

18+00

24+00

30+00

36+00

42+00

48+00

54+00

60+00

66+00

Test Location

Defl

ect

ion

(m

ils)

Rigid Pavements

Locate areas of poor support beneath jointedconcrete pavements.Determine load transfer efficiency across jointsand cracks.Estimate subgrade and pavement layer elasticmoduli values.Develop cost-effective maintenance andrehabilitation alternatives.

IDOT’s FWD Program

Project Level Testing is ≥ 95%3 Main Areas– Local Agency Testing– Monitoring of Experimental Sections– Seasonal Variation Program

Local Agency Testing

Counties, Cities, Townships, Airports20 to 25 Projects / YearEstimate Remaining Life and OverlayThickness Requirements

Monitoring ofExperimental Sections

2/3 of TestingDowel Bar ExperimentATREL Test SectionsRubblizing ProjectsOpen-Graded Drainage LayersMechanistic DesignsMiscellaneous

Seasonal Variation Program

Monthly testing performed at 4locations in the Springfield area.Measured deflections can vary greatlydepending on temperature andmoisture conditions.Deflection data collected during non-critical period is adjusted to reflectworst-case scenario.

Questions?

LaDonna Rowden Sharon Haasis(217) 782-8582 (217) 782-0551rowdenlr@nt.dot.state.il.us haasissl@nt.dot.state.il.us

Charles Wienrank(217) 782-0570wienrankcj@nt.dot.state.il.us