Multimodal Condition Assessment of Bridge Decks by Non-Destructive Evaluation 2010 Midwest Bridge Preservation Partnership Annual Meeting October 12-14, 2010 AISI Bridge Task Force 222010AASHTO T-14 Committee Cedar Rapids, IA April 8, 2008
Multimodal Condition Assessment of Bridge
Decks by Non-Destructive Evaluation
2010 Midwest Bridge Preservation
Partnership Annual Meeting October 12-14, 2010
AISI Bridge Task Force
222010AASHTO T-14 Committee
Cedar Rapids, IA
April 8, 2008
Multimodal Condition Assessment of
Bridge Decks by Non-Destructive Bridge Decks by Non-Destructive
Evaluation (NDE) and Its ValidationNenad Gucunski, Ruediger Feldmann, Francisco Romero, Sabine
Kruschwitz,
Rutgers University
Center for Advanced Infrastructure and Transportation (CAIT)
Norm McDonald, Ahmad Abu-Hawash
Iowa Department of Transportation
Location of Tested Bridges
Iowa Bridge Deck Evaluation
Implemented NDE technologies
• Ground penetrating radar (GPR)
• Impact echo (IE)
• Ultrasonic pulse echo
• Ultrasonic surface waves
• Half-cell potential
• Electrical resistivity
Complementary evaluations/validations
• Coring
• Chain drag
NDE Techniques
GPRGPR Ultrasonics
Resistivity
Seismic/Ultrasonic
Impact Echo
Half-Cell
Ultrasonics and
Impact Echo
Deterioration Types Vs. NDE Method
Corrosion• Half-cell potential – Likelihood of corrosion
• Electrical resistivity – Potential for corrosive environment
• GPR – Potential for corrosive environment• GPR – Potential for corrosive environment
Concrete Degradation• Ultrasonic surface waves (USW) – Modulus degradation
• GPR – Likelihood of deterioration
Delamination• Impact echo
• Ultrasonic pulse echo
• GPR – Likelihood of delamination in severely attenuated areas Bridge Monitoring: NDE
Bridge Deck Condition Assessment
REBAR CORROSION DELAMINATION SPALLING
BRIDGE DECK CONDITION
GPR
IMPACT ECHO
HAMMER SOUNDING/CHAIN DRAG
VISUAL INSPECTION
TIME
HALF-CELL POTENTIAL
ULTRASONICS
Data Collection – Test Grid
Half-Cell Corrosion Potential
Electrical Resistivity – Wenner Probe
Electrical Resistivity, kohm/cm
Ground Penetrating Radar (GPR)
GPR – Raw Scan and Condition Map
Deteriorated Zone
De-bonded O/L
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
DISTANCE FROM EAST ABUTMENT (FEET)
Top Rebar Amplitude (Normalized dB) - DEPTH CORRECTED
0
10
20
-22 -20 -18 -16 -14 -12 -10 -8
Impact Echo and Ultrasonic Testing
Stepper – Ultrasonics and Impact Echo
Evaluation of Modulus and Deck Thickness by UBW and IE
travel time
t
A
f
returnfrequencyVp
thickness
21
AIEUBW
1 2
IE on a Delaminated Deck
DELAMINATION
IMPACT
SOURCE
t = V / 2ft
p
RECEIVER
T
Depth, %
75250 100
Amplitude
Frequency, kHz
4020100 30
Amplitude
50
f
DELAMINATED
SOLID
Deck Condition Grades
Amplitude
RECEIVERIMPACT
SOURCE
T
GOOD (INTACT) CONDITION
Concrete is well
bonded and no signs
of delamination are
detected.
Amplitude
RECEIVERIMPACT
SOURCE
T
FAIR CONDITION
Concrete is bonded
or in contact, but
there are signs of
delamination at
some depths.
Frequency, kHz
4020100 30fTFrequency, kHz
4020100 30fT
Frequency, kHz
4020100 30
Amplitude
DELAMINATION
IMPACT
SOURCE
t
f
RECEIVER
T
DELAMINATED
SOLID
SERIOUS CONDITION
There is complete
loss of bonding and
separation of concrete
layers.
Frequency, kHz
4020100 30
Amplitude
DELAMINATION
IMPACT
SOURCE
t
f
POOR CONDITION
RECEIVER
T
DELAMINATED
SOLID
Delamination has
occurred, however
grain to grain contact
between the two
concrete layers
exists.
Impact Echo Delamination Assessment
Note:
White lines
represent
boundaries
determined
by chain
drag
Modulus Evaluation by USWRT. I-495S - SPAN6
10
12
14
16
Longitudinal distance, m
Shear Mod.(MPa)14700+
14000 to 14700
13300 to 1400012600 to 13300
RT. I-495S - SPAN 6Two Left Lanes
SHEAR MODULUSDISTRIBUTION
Modulus
vs.
depth
Average
Modulus0 1 2 3 4 5 6
Lateral distance, m
0
2
4
6
8
Longitudinal distance, m
12600 to 13300
11900 to 1260011200 to 11900
10500 to 11200
9800 to 10500
9100 to 98008400 to 9100
7700 to 84007000 to 7700
Good
-800
-600
-400
-200
0
mV-21.75
-18.75
-15.75
-12.75
-9.75
dB
Good
Fair
Poor
Serious
No
Signal1.0
2.0
3.0
4.0
5.0
6.0
cm
O1
mV
dB
O2Good
Fair
Poor
Serious
No
Signal
kohm*cm
O2
O6 dBmV
Good Fair Poor Serious No
signal
kohm*cm
Conclusions
• Condition assessment of bridge decks using NDE
technologies has shown their ability to detect and
characterize different types and levels of deterioration.
• Half-cell potential and electrical resistivity measurements enable
assessment of likelihood and severity of corrosion.
• GPR provides information about deterioration/alteration of
concrete.
• Impact echo and ultrasonic measurements enable detection and
characterization of delamination in the deck. Delamination
detection was validated through the comparison with cores
taken and selected locations.
• Complementary approach in NDE bridge deck evaluation
provides a more comprehensive condition assessment.
Thank you!
Questions?