Portorož, Slovenia

Quantifying the Impact of Jointed Concrete Pavement Curling and Warping on Pavement Unevenness

•George Chang, PhD, PEGeorge Chang, PhD, PE

•Transtec GroupTranstec Group

•Project ManagerProject Manager

•gkchang@theTranstecGroup.comgkchang@theTranstecGroup.com

T H ETRANSTEC GROUPTHE

Portorož, Slovenia

US FHWA Curl/Warp Study

o Impact of Curling and Warping on JCP Performance

Portorož, Slovenia

Outlines

o Curl/Warp Measurement o Profile Synchronization and Joint

IDo 2GCI Curvature Indexo RoCK System for Curvature-

Impact-Roughess Analysis

Portorož, Slovenia

Curl/Warp Measurement

o What to be measured?• Site Selection• Data Collection

o How to measure?• Profiling• Temperature• Others

Portorož, SloveniaSeasonal SiteNon-seasonal Site

Selected Sites

Dry-Freeze

Wet-NonfreezeDry-Nonfreeze

Wet-Freeze

Portorož, Slovenia

Diurnal Profiling

-1

-0.5

0

0.5

1

1.5

2

2.5

12:00 PM 4:00 PM 8:00 PM 12:00 AM 4:00 AM 8:00 AM 12:00 PM 4:00 PM

Time of Day

Tem

per

atu

re G

rad

ien

t (d

eg F

/in

ch)

Inertial Profiling

-1

-0.5

0

0.5

1

1.5

2

2.5

12:00 PM 4:00 PM 8:00 PM 12:00 AM 4:00 AM 8:00 AM 12:00 PM 4:00 PM

Time of Day

Tem

per

atu

re G

rad

ien

t (d

eg F

/in

ch)

Early AM

Mid-AM

Late AM - Early PM

Evening

Critical Passes!!

Portorož, Slovenia

Outlines

o Curl/Warp Measurement o Profile Synchronization and Joint

IDo 2GCI Curvature Indexo RoCK System for Curvature-

Impact-Roughess Analysis

Portorož, Slovenia

Raw Profile

0 50 100 150 200 250 300Distance (m)

-20

-10

0

10

20Left Elevation (mm)

IA_023A

Portorož, Slovenia

Spike Profile

0 50 100 150 200 250 300Distance (m)

-15

-10

-5

0

5

10"Spike" Profile

Filter with moving average anti-smoothingNormalize by RMSSearch deepest dip by a threshold

Portorož, Slovenia

Spike Incidence

0 50 100 150 200 250 300Distance (m)

100

80

40

20

0Spike Incidence (percent)

Assemble the dip count across the data set

Portorož, Slovenia

Weeded Spike Incidence

0 50 100 150 200 250 300Distance (m)

80

60

40

20

0Weeded Spike Incidence (percent)

Weed/clear false hitsExtract the joint locations

Portorož, Slovenia

Outlines

o Curl/Warp Measurement o Profile Synchronization and Joint

IDo 2GCI Curvature Indexo RoCK System for Curvature-

Impact-Roughess Analysis

Portorož, Slovenia

Westergaard Curling Formula

2

sinh2

sintanhtan2

cosh2

costanhtan2sinh2sin

coshcos2

l

x

l

x

l

x

l

xzz o

-0.006

-0.004

-0.002

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

-150 -100 -50 0 50 100 150

Distance from Slab Center (inches)

De

fle

cti

on

(in

ch

es

)

-10

0

10

20

30

40

50

60

70

80

90

Str

es

se

s (

ps

i)

Deflection (Modified eq.)(inches)

Transv. Stresses at Top (psi)

Portorož, Slovenia

Adjusted Westergaard Curling Parameters

o Adjusted to overcome Westergaard assumptions

o Fit to actual slab deformationo More fundamental than an arbitrary

geometric functiono Fitted parameters:

• Pseudo-radius of relative stiffness• Pseudo-strain gradient

Portorož, Slovenia

2GCI Fit – Curled Down Slab

25-mm data

Portorož, Slovenia

2GCI Computation

o Isolate the individual slab segmentso De-trend and de-mean the profile

segmento Mask jointso Define model parameterso Perform nonlinear curve fitting

Portorož, Slovenia

2GCI AnalysisAZ_001am - winter

-35

-30

-25

-20

-15

-10

-5

0

5

10

15

20

0 10 20 30 40 50 60 70 80

Slab Number

Pse

ud

o G

rad

ien

t (m

e /cm

)

Early AM Mid AM Noon Late PM

Portorož, Slovenia

2GCI AnalysisAZ_001am - winter

-40

-30

-20

-10

0

10

20

30

40

Early AM Mid AM Noon Late PM

Pse

ud

oG

rad

ien

t D

istr

ibu

tio

n (me /

cm)

Quartile 1

Minimum

Median

Maximum

Quartile 3

Portorož, Slovenia

2GCI AnalysisMN_046a - summer

-20

-10

0

10

20

30

40

50

60

70

0 5 10 15 20 25 30 35

Slab Number

Pse

ud

o G

rad

ien

t (m

e /cm

)

Early AM Mid AM Noon Late PM

Portorož, Slovenia

2GCI AnalysisMN_046a - summer

-20

-10

0

10

20

30

40

50

60

70

Early AM Mid AM Noon Late PM

Pse

ud

oG

rad

ien

t D

istr

ibu

tio

n (me /

cm)

Quartile 1

Minimum

Median

Maximum

Quartile 3

Portorož, Slovenia

Mean Curvatures

MN

_044

aN

V_0

47g

NV

_047

hIL

_027

aIL

_029

aU

T_0

58a

MN

_043

aIL

_028

aA

Z_0

02b

IL_0

26a

AZ

_002

aA

Z_0

01a

WA

_060

aC

A_0

08e

NC

_047

cK

S_0

32d

NE

_047

fK

S_0

32c

KS

_032

fM

I_04

0aN

C_0

47d

IA_0

23a

NC

_047

aK

S_0

32e

KS

_038

aO

H_0

50b

OH

_052

bW

I_06

7aO

H_0

52e

NC

_047

bG

A_0

19a

FL_

010a

IA_0

21a

FL_

011a

NE

_047

eN

Y_0

49a

TX

_055

aW

A_0

62a

WA

_062

bM

N_0

44b

OH

_050

cA

Z_0

03a

PA

_053

aK

S_0

38c

WI_

063a

OH

_052

aK

S_0

38b

OH

_052

cO

H_0

52d

FL_

016a

GA

_018

aM

N_0

46a

-40

-30

-20

-10

0

10

20

30

40

Pse

ud

o-g

rad

ien

ts (me

/cm

)

Portorož, Slovenia

Outlines

o Curl/Warp Measurement o Profile Synchronization and Joint

IDo 2GCI Curvature Indexo RoCK System for Curvature-

Impact-Roughess Analysis

Portorož, Slovenia

2GCI vs RoughnessAZ_001m

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

0:00 4:48 9:36 14:24 19:12 0:00

Time

HR

I (m

/km

) Spring

Summer

Fall

Winter

Portorož, Slovenia

2GCI vs RoughnessAZ_001m

-16

-14

-12

-10

-8

-6

-4

-2

0

0:00 4:48 9:36 14:24 19:12 0:00

Time

Me

an

Ps

eu

do

-Gra

die

nt

(me /

cm

)

Spring

Summer

Fall

Winter

Portorož, Slovenia

2GCI vs RoughnessAZ_001m

0.6

0.8

1

1.2

1.4

1.6

1.8

-16 -14 -12 -10 -8 -6 -4

Mean Pseudo-gradient (me/cm)

HR

I (m

/km

) Spring

Summer

Fall

Winter

Portorož, Slovenia

Roughness

Curvature (downward)

Curvature (upward)

0CrtClf

Rub

Rlb

Rzc

The RoCK Chart

Portorož, Slovenia0

Rub

Rlb

Rzc

Rbtc

Curvature-related Roughness

Non Curvature-related Roughness

Roughness DecompositionRoughness Decomposition

Portorož, Slovenia

Roughness

Curvature (downward)

Curvature (upward)

0CrtClf

Rub

Rlb

Rzc

TYPE I-A Sites

Curled upCurvature dominates

roughness

Src < 0Rbtc > 0

Portorož, Slovenia

Roughness

Curvature (downward)

Curvature (upward)

0CrtClf

Rub

RlbRzc

TYPE I-B Sites

Curled up mildlyCurvature affects

roughness

Src < 0Rbtc ~ 0

Portorož, Slovenia

Roughness

Curvature (downward)

Curvature (upward)

0CrtClf

Rub

RlbRzc

TYPE II SitesCurled up and downCurvature affects Roughness mildly

Src < 0Rbtc ~ 0

Src > 0Rbtc ~ 0

Portorož, Slovenia

Roughness

Curvature (downward)

Curvature (upward)

0 CrtClf

Rub

Rlb

Rzc

TYPE III-A Sites

Curled downCurvature dominates

roughnessSrc > 0Rbtc > 0

Portorož, Slovenia

Roughness

Curvature (downward)

Curvature (upward)

0CrtClf

Rub

RlbRzc

TYPE III-B Sites

Curled down mildlyCurvature affects

roughness

Src > 0Rbtc ~ 0

Portorož, Slovenia

Bolivian Project

o Two-lane undivided JCPo Mountainous terrain with moderate fills

and cutso 24-ft wide, 12-ft joint spacingo 8-inch slab on 6-inch granular baseo Local climate is arid with rains from

December to Marcho Drastic overnight temperature drops

Portorož, Slovenia

Bolivian Project

o Low relative humidity and extreme temperatures

o Mix with a relatively high water cement ratio, high CTE aggregate, and inadequate curing techniques.

o Longitudinal cracks at the center of the slab in both travel directions after the first winter

Portorož, Slovenia

Bolivian Project-300

-200

-100

0

100

200

300

PT

Ca

ma

rgo

PT

Isc

aya

chi-1

PT

Cie

ne

gu

illa

s

PT

El P

ue

nte

PT

Circ

un

vala

cio

n

AH

-1

AH

-2

AH

-3

Oru

ro-T

ole

do

Cot

ap

ata

Sta

. B

arb

ara

Pte

. S

acr

am

en

to

Sa

n J

osé

-Ro

bo

ré

Pavement SectionP

seu

do

-gra

die

nt

(me /

in.)

Quartile 1

Minimum

Median

Maximum

Quartile 3

AM

Portorož, Slovenia

Bolivian Project

Portorož, Slovenia

Bolivian Project

Effect of curling and loading-current geometry

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

Legal limit loadonly

Loading on 28Ton tandem only

Curling + legalload

Curling + loadon 28 ton tandem

curling + load on20 Ton simple

axle

Str

esses (

Kp

a)

Strength

FEM Analysis

Portorož, Slovenia

The Implications…

o What’s timing to measure roughness for a pavement acceptance testing?

o What’s the best practice to avoid curl and warp?

o What’s the best time to grind the pavements to improve smoothness?

Portorož, Slovenia

Tools you can use…

o New, robust profile synchronization and joint identification techniques

o Invention of 2GCI to better characterize slab curvature

o New, effective slab curvature analysis framework

o RoCK System to assess curvature’s impact on roughness

Portorož, Slovenia

Acknowledgement

o US FHWA Sponsorshipo Co-authors:

• Steven M. Karamihas, University of Michigan, USA• Robert Otto Rasmussen, P.E., Ph.D., The Transtec Group,

Inc., USA• David Merritt, P.E., M.S., The Transtec Group, Inc., USA• Mark Swanlund, P.E., US DOT Federal Highway

Administration, USA

o Many US State DOT for assistance in field measurements