PE 2019

Investigation of Profile-Based Curl and Warp Analysis Using LTPP Profile Data

By

Steven M. Karamihas

University of Michigan Transportation Research Institute

With Kevin Senn and Timin Punnackal, NCE

And Larry Wiser, FHWA

PE 2019

AZ Section 040213, Upward Curl

Source: FHWA

PE 2019

•Estimate the level of curl and warp of JPCC using profile.

•Relate curl and warp to roughness.

•Refine an existing method.

•Apply the method to a broader set of sections.

“What would the roughness be without curl and warp?”

Advancement of Curl and Warp…..

PE 2019

•Locate the joints.

• Isolate slab profiles.

•Fit slab profiles to an assumed function (Westergaard).

•Cast the result in terms of strain gradient.

•Aggregate over a test section.

Core Method (Chang, Rasmussen, et al.)

PE 2019

Joint Finding

© FHWA

PE 2019

Isolated Slab Profile

Source: FHWA-HRT-12-068

-100 -50 0 50 100

Longitudinal Distance (in)

-.1

0

.1

.15

Detrended Profile (in)

.05

-.05

PE 2019

-100 -50 0 50 100

Longitudinal Distance (in)

-.1

0

.1

.15

Slab Profile (in)

.05

-.05model

measurement

Fitted Slab Profile

Source: FHWA-HRT-12-068

PE 2019

Westergaard Model

PE 2019

Idealized Slab Shapes

Source: Rasmussen

-100 -50 0 50 100

Dist. from Slab Center (in)

-.2

0

.2

.4

Vertical Slab Deformation (in)

-100 -50 0 50 100

-0.002

0

0.002

0.004

0.006

Dist. from Slab Center (in)

Vertical Slab Deformation (in)

RRS (l) = 10 inchesPSG = -40 με/inch

RRS (l) = 80 inchesPSG = -40 με/inch

PE 2019

Structural Evaluation, Spatial Trends

© FHWA

Downward Curl

Upward Curl

PE 2019

Structural Evaluation, Trends Over Time

© FHWA

PE 2019

Structural Evaluation, by Test Section

© FHWA

PE 2019

IRI Versus PSG, Hypothesis

TRB 2008, Session 573

-40 -35 -30 -25 -20 -15 -10 -5 0

Mean Pseudo-Gradient (me/in)

Mean Roughness Index (in/mi)

20

40

60

80

100

120

PE 2019

-40 -35 -30 -25 -20 -15 -10 -5 0

Mean Pseudo-Gradient (me/in)

Mean Roughness Index (in/mi)

20

40

60

80

100

120

IRI Versus PSG, Hypothesis

TRB 2008, Session 573

PE 2019

Idealized Profile (l = 40 inches)

© FHWA

PE 2019

IRI versus PSG

© FHWA

PE 2019

IRI/PSG Slope

© FHWA

PE 2019

Uplift and PSG

© FHWA

PE 2019

IRI Versus Uplift

© FHWA

PE 2019

Idealized Curl and Background Roughness

© FHWA

+

PE 2019

Idealized Curl and Background Roughness

© FHWA

PE 2019

Idealized Curl and Background Roughness

© FHWA

PE 2019

Background Roughness

© FHWA

PE 2019

Section-Wide PSG Average

© FHWA

PE 2019

IRI versus PSG, FHWA Data

© FHWA

PE 2019

IRI versus Uplift, FHWA Data

© FHWA

PE 2019

IRI versus Uplift, LTPP Data

© FHWA

PE 2019

IRI versus Uplift, LTPP Data

© FHWA

PE 2019

•The fitted values relating IRI to uplift were not systematically related to the theory.

•This could be caused by:•The structural model.

•The “sum of squares” model.

•The low number of slabs per section.

•Some other thing I haven’t noticed.

Assessment

PE 2019

•Notice something new.

•Difference profiles.

•Spectral methods.

•Specialized filters.

•“Advanced” methods.

Possible Next Steps...

2 5 10 2 5 100Wavelength (ft/cycle)

0.1x10-7

0.1x10-6

0.1x10-5

0.1x10-4

0.1x10-3

0.1x10-2

PSD of Left Slope (ft/cycle)

11-Aug-2006

30-Dec-2007

PE 2019

The Report…...

is in the editing phase.

Thank you!!!!