May 2009 Update On Aashto Rut&Crack Etg

ETG on Quantification of Pavement Cracking and Rutting

Proposed Standards for Measurement of Cracking and Rutting

May 2009

US Department of TransportationFederal Highway Administration

Why New Standards?1.Expiration of AASHTO Provisional Standards

PP-38 and PP-442.Development of newer technology3. Increasing need for precision and accuracy

Provisional Standard 38Now AASHTO Standard R 48-09

Proposed new Standards for Transverse Profile

1.Transverse Profile Measurement2.Transverse Profile Analysis

Data Standards -Transverse Profile Measurement

Scan Lane + 400 mm

≤10mm

Resolution within 1mm

Lane Line

±5° max

Transverse Profile

Transverse ProfileAnalysis

Centerof Lane

1. Calculate Cross-slope

CL

Roadway

Average elevationof right ½ lane

Average elevationof left ½ lane

Shoulder

Transverse ProfileAnalysis

Centerof Lane

1. Calculate Cross-slope

CL

Roadway

Average elevationof right ½ lane

Average elevationof left ½ lane

Shoulder

Transverse ProfileAnalysis

CL

1 2 3

2. Calculate Percent Deformation:

RoadShoulder

Transverse ProfileAnalysis

CL1

2

3

4

5

3. Calculate Rut Depths

RoadShoulder

Transverse ProfileAnalysis

3. Calculate Rut Depths

CL1

23

45

Roadway Shoulder

Transverse ProfileAnalysis

Centerof Lane

3. Calculate Rut Depths

CL

Roadway

12

3 4 5

Shoulder

Transverse ProfileAnalysis

4. Calculate Rut Area

CL1

2

3

4

5

Lane

Provisional Standard 44Expiring in 2009

Provisional Standard 44

Usual Lane Width 3.6 m

Pavement SurfaceSurvey Lane

Adjacent LaneShoulder ofAdjacent Lane

Lane

Lin

e

Lane

Lin

e

*Varies*Varies

Survey Strip2.500 m

InsideWP

OutsideWP

Areabetween

WPs

*Optional

0.125 0.125

0.75 0.75 0.75

0.125 m = 0.41 ft0.75 m = 2.5 ft3.6 m = 12 ft

Proposed Standard for measuring pavement cracking

• Image Characteristics• Detection Minimums• Reporting

Pavement cracking

4.0 m minimum4.25 m preferred

100 mMax.

Pavement crackingDetection Criteria:

Resolution ≤ 1 mmMin. Detection

• 30% if width is ≤ 3 mm • 50% if width is 3 mm to 5 mm• 85% if width is ≥ 5mm wide

False positives ≤ 3 m in 50 m2

Crack width within 20%

Proposed Standard for analyzing pavement cracking

• Uses 5 zones• Classifies into 3 types• Classifies by extent and severity

Pavement cracking

1 2 3 4 5Zones(Shoulder)

.75m .75m.875m .875m

ETG Activities:1. Finalize R48 (5-point Rutting Method)2. Submit Proposals for Automated

Methods to AASHTO SOM Technical Committee 5a.

3. Conduct Verification Project4. Present Methodology to Pavement

Community.5. Work with AASHTO Committee to

finalize standards.

ETG State Members:

Rick Miller, Kansas DOTJohn Andrews, Maryland DOTJeff Seiders, Texas DOTBouzid Choubane, Florida DOTCole Mullis, Oregon DOTJudith Corley-Lay, North Carolina DOTTodd Copenhaver, Texas DOT

ETG Industry Members:

Gary Elkins, MACTECChuck Larson, STANTECFrank Holt, DynatestRichard Fox-Ivey, Fugro-RoadwareJerry Daleiden, FCLAU

ETG FHWA Members:

Thomas Van, HQ Asset ManagementJack Springer, TFHRCAndrew Mergenmeier, RCMike Moravec, HQ Pavements

For more information:

Thomas VanFHWA – Office of Asset ManagementTel. 202-366-1341Email: thomas.van@dot.gov

Rick MillerKansas DOT785-291-3842Email: Rick.Miller@ksdot.org