1

Assessment of pavement damage

KTHAF2903 Road Construction and Maintenance01 April 2014

Assessment of pavement damageor

Quantitative measurement techniques

Sigurdur Erlingssonsigurdur.erlingsson@vti.seVTILinköping

Why is it important to assess the condition of pavements ?

• Pavement Management Systems (PMS) is a set of• Pavement Management Systems (PMS) is a set of tools or methods to assist decision makers in finding a optimum strategies for providing, evaluating and maintaining pavement in a serviceable conditions over a period of time.

• PMS provides a rational and cost effective approach• PMS provides a rational and cost-effective approach to pavement maintenance operations.

2

Methods

• Visual survey• Profile measurements• Wear due to studded tyresWear due to studded tyres• Coring and sampling

– Material testing• Skid resistance• Falling Weight Deflectometer (FWD)• Lateral wander• Roughness (smoothness)• Continuous scanning – Road Surface tester (RST)

R h R t Vid fili Di it l i t– Roughness, Rut, Video profiling, Digital images, etc.• Pavement Instrumentation

– Temperature and moisture– Frost penetration – Response sensors

Visual survey (inspection)

Visual inspection includes:• Cracking

Longitudinal– Longitudinal • Fatigue cracking

– Single crack in the wheel path– Alligator cracking

• Seasonal (frost heave) cracks• Joint cracking

– Transversal (thermal) cracking – Pattern cracks

• Block Cracking• Joint Reflection Cracking

• Potholes• Bleeding• Ravelling• Corrugation and shoving• Segregation• Patching• Depressions

3

Visual survey cont.

Inspection 1 Inspection 2 Inspection 3

Crack index, Si = 7 Crack index, Si = 46 Crack index, Si = 103

1 LSprlå längd 2 m Krlå 6 m Kr d l 8 m1. LSprlåg, längd 2 m Krlåg, 6 m Krmedel, 8 m

2. LSprlåg, 1 m LSprsvår, 3 m Krlåg, 7 m

3. LSprmedel, 2 m LSprsvår, 3 m

4. TSprlåg, 1 st

5. LSprlåg, 2 m LSprmedel, 4 m

6. LSprlåg, 3 m Krlåg, 3 m

7. LSprlåg, 2 m LSprsvår, 4 m

8. LSprmedel, 3 m Krmedel, 6 m

9. TSprlåg, antal 1 st TSprmedel, 1 st

10. LSprmedel, 2 m Krmedel, 4 m Krsvår, 5 m

Profile measurements

4

Profile measurements cont.

5

-10

-5

0

5

0 1000 2000 3000 4000

Pro

fil

(mm

)

1996-10-21

1997-10-15

1998-11-17

1999-10-20

2000-10-18

2001-10-15

2002-10-15

-20

-15

10

Profillängd (mm)

P

2003-10-14

2004-10-13

2005-10-13

2006-10-17

Profile measurements cont.

Skandiahamnen Göteborg Västra stråketTvärprofil 5Tvärprofil 5

15

-10

-5

0

5

10

15

20

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

11000

12000

13000

14000

d (

mm

)

05-12-13

06-12-10

-45

-40

-35

-30

-25

-20

-15

Sektion (mm)

Hö

jd

07-11-11

5

Wear due to studded tyres

-0,5

0

0,5

1

0 0,5 1 1,5 2 2,5 3 3,5 4 4,5

ge

(mm

)

-2,5

-2

-1,5

-1

Profil (mm)

Sli

tag

Coring and sampling

6

Coring and sampling – Material testing

Laboratory testing:IDT TestRLT testetc.

Skid resistance

7

Skid resistance cont.

Skid resistance is the force developed when a tyre, that is prevented from rotating, slides along the pavement surface

0,80,91,0

along the pavement surface.

Friction factor: f = F/LSkid number: SN = 100(f)where: F = frictional resistance to motion in plane of interface. L = load perpendicular to interface.

0,00,10,20,30,40,50,60,7

0 100 200

Sektion (m)

Fri

ktio

n

Falling Weight Deflectometer (FWD)

r0 r1 r2 r3 r4 r 5

D0

D1

D2

D3D4

D 5

F

8

FWD - results

0

1.jan 31.jan 2.mar 1.apr 1.maí 31.maí 30.jún 30.júl 29.ágú

0

150

300

450

600

D0

[µm

]

8m6m2m0m-2m-6m-8m

Base Course - Depth 0 - 20 cm

100

1000

10000

100000

1.jan 31.jan 2.mar 1.apr 1.maí 31.maí 30.jún 30.júl 29.ágú

E1

[MP

a]

Lateral wandering (side position)

Passengers cars

Heavy vehicles

9

Roughness (Smoothness)

• Roughness is a measure of the texture of a surface. It is quantified by the vertical deviations of a real surface from its ideal form. If these deviations are large, the surface is rough; if they are small the surface is smooth. Roughness is typically considered to be the high frequency, short wavelength component of a measured surface

IRI = International Roughness Index

component of a measured surface.

• Profilometer is used to measure a surface's profile, in order to quantify its roughness. Vertical resolution is usually in the nanometre level, though lateral resolution is usually poorer.

• worldwide standard for measuring pavement smoothness called the International Roughness Index, or IRI. The index measures pavement roughness in terms of the number of mm per m (inches per mile) that a laser, mounted in a specialized van, jumps as it is driven across the road system. The lower the IRI number, the smoother the ride.

• A measure of a pavement's longitudinal surface profile as measured in the wheel path by a vehicle travelling at typicalmeasured in the wheel path by a vehicle travelling at typical operating speeds. It is calculated as the ratio of the accumulated suspension motion to the distance travelled obtained from a mathematical model of a standard quarter car traversing a measured profile at a speed of 80 km/h (50 mph). The IRI is expressed in units of meters per kilometer (inches per mile) and is a representation of pavement roughness.

Response Type Road Roughness Meters (RTRRMs)RTRRMs measure the vertical movements of an automobile or the axle of a trailer relative to the vehicle frame. The meters are installed in vehicles with a displacement transducer on the body located between the middle of the axle and the body of a passenger car or trailer. The transducer detects small increments of axle movement relative to the vehicle body. The output data consists of a strip chart plot of the actual axle body movement versus the time of travel.

Roughness - IRI

• The international roughness index (IRI) was developed by the W ld B k i th 1980 IRI iWorld Bank in the 1980s. IRI is used to define a characteristic of the longitudinal profile of a travelled wheel-track and constitutes a standardized roughness measurement.

• The commonly recommended units are meters per kilometer (m/km) or millimeters per meter ( / )(mm/m).

10

Continuous scanning

Road Surface Tester (RST)

11

Road Surface Tester (RST)

RST - what is measured

• Three longitudinal profiles (0.1 meter)

T fil (1 t )• Transverse profile (1 meter)

• Rut depth, max, left and right (20 meter)

• IRI, left and right (20 meter)

• Macrotexture, MPD in three tracks (1 meter)

• Megatexture, two tracks (1 meter)g , ( )

• Curvature, Hilliness (20 meter),

• Crossfall (1 meter)

• Digital images (20 meter)

12

SNRA´s PMS data

6.00 20.00

Road Surface ConditionHallands län , Väg: 6.00

Sträcka: 0 - 5000, Körfält: 10, Riktning: Framåt, Sida för vägdata: 1

VÄGVERKET

PMS

20091125, 15.37

Vägversion: 20090923

0 1000 2000 3000 4000 5000

Vägbredd(m) 11.3

Trafik(ÅDT) 9393 5500 9591

Tung traf(ÅDT) 1725 900 1738

Bel.lager 1 1) 2) 0ABS1105

Bel.lager 2 3) 0.05 0.05

Bel.lager 3 4) 5) 0ABb1105

1)43.478240967,2)0ABS1105,3)34.782592773,4)39.1304016115)0ABb1105,

Spårdjup(mm)

10

5

0

OjämnhetIRI(mm/m)

1999-04-22 2000-05-22 2001-05-08 2002-05-08 2003-05-10 2004-05-072006-05-29 2007-06-25 2008-05-12 2009-05-06

Best1

20

15

0123456

SNRA´s PMS data

648.00 646.00

VÄGVERKET PMS 19981022, 17.58

Vägversion: 970727 Example Road GraphDalarnas län , Väg: 60.00

Sträcka: 50000 - 55000, Körfält: 10, Riktning: Framåt, Sida för vägdata: 1

50000 51000 52000 53000 54000 55000

Trafik(ÅDT) 4450 6400

Vägbredd(m) 13.0

Bel.lager 1 32HABS1294 32HABT1285Bel.lager 2 0MABT1694 44AG258444AG3284Bel.lager 3 0Y1B1683 44AG3284

Spårdjup

(mm)

1510 5 0

OjämnhetIRI(mm/m)

930601 940530 940912 950607 960609 970605

2015

0123456

13

Network level: Rut depth

Digital Images

20 m interval between the frames

14

Längd Km

80000

90000

Total measured length (lane km) with RST

30000

40000

50000

60000

70000

Km Längd Km

0

10000

20000

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

År

Change in longitudinal unevenness Percentage IRI>4 mm/m AADT>2000 vehicles/day

15

Change in transverse unevenness Percentage Rut depth>15 mm AADT>2000 vehicles/day

Frost depth penetration

www3.vv.se/tjaldjup/

16

Instrumented test roads - APT testing

Technical SpecificationsT t h l D l i l h l

The HVS Nordic is a mobile APT Test wheel: Dual or single wheelLoad range: 30 – 110 kNCapacity: 150 000 passages/weekLoading direction: single or bi-directionalMax speed: 12 km/hLateral wander: 0 – 0.7 mPavement temp: 0 – 30°CPower: Diesel or electricity

test facility.

APT = Accelerated Pavement TestingHVS = Heavy Vehicle Simulator

Instrumentation - Response measurements

Asphalt Concrete

Bituminous Base

Granular Base Course

0.0

4.8

10.1

20.9

D th [ ]

Granular Subbase

Subgrade, sand

35.1

Instrumentation

Pressure cell

Horizontal strain, longitudinal

Horizontal strain, transversal

Vertical strain

V ti l d fl tiDepth [cm] Vertical deflection

-200

0

200

400

600

800

0 500 1000 1500 2000Time, t [ms]

stra

in, t

[

]

ASG 107 - X

ASG 108 - Y

-200

0

200

400

600

800

0 500 1000 1500 2000Time, t [ms]

stra

in, t

[

]

ASG 107 - X

ASG 108 - Y

17

Instrumentation - stress measurements

600

700

SPC69 250

300

SPCB

Base course Subbase Subgrade

80

100

SPC27

FEM

0

100

200

300

400

500

1,9 2,0 2,1 2,2 2,3

Time [sec]

Str

ess

[kP

a]

SPC69

SPC67

SPC65

FEM

0

50

100

150

200

1,4 1,5 1,6 1,7 1,8 1,9 2,0

Time [sec]

Str

ess

[kP

a]

SPCB

SPC30

FEM

0

20

40

60

80

1,4 1,5 1,6 1,7 1,8 1,9 2,0

Time [sec]

Str

ess

[kP

a]

FEM

The Swedish LTPP database

0 5

1.0

1.5

2.0

IRI

[-]

Rv31 Nässjö - Mean

R 31 Nä jö

0.0

0.5

1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008Date

0

5

10

15

20

1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008

Cra

ck in

dex

[-]

Rv31 Nässjö - Crackindex, mean

8,5

20,0

0,0

Sb

BC

AC

70,0

Rv 31 Nässjö

0

2

4

6

8

10

12

14

16

1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008Date

Rut

[m

m]

Rv31 Nässjö - Mean

Date

LTPP = Long Term Pavement Performance

Depth [cm]

Sg