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TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Overview of FHWA Current Coatings and Corrosion Research Programs
Overview of FHWA Current Coatings and Overview of FHWA Current Coatings and Corrosion Research ProgramsCorrosion Research Programs
Seung-Kyoung LeeManager of Coatings and Corrosion Laboratory
Office of Infrastructure R&DTurner-Fairbank Highway Research Center
Federal Highway Administration
AASHTO Bridge 2009, New Orleans, July 6, 2009
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Current Research ProgramsCurrent Research ProgramsCoatingsCoatings• Performance Evaluation of One-Coat Systems• Exploration of 100-Year Maintenance-Free Coating Systems• Development of Field Coating Performance Monitoring MethodologyCorrosionCorrosion• Laboratory Evaluation of Corrosion Resistance of Metallic Dowel Bars• Field Performance Monitoring of a Thin Polymer Overlay (TPO)• Development of a Design Guideline for Selecting Optimum Rebar
Materials in Concrete Bridge Decks• Evaluation of NDE Technologies for High Strength Wire Corrosion
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Current Research ProgramsCurrent Research ProgramsCoatingsCoatings• Performance Evaluation of One-Coat Systems• Exploration of 100-Year Maintenance-Free Coating Systems• Development of Field Coating Performance Monitoring MethodologyCorrosionCorrosion• Laboratory Evaluation of Corrosion Resistance of Metallic Dowel Bars• Field Performance Monitoring of a Thin Polymer Overlay (TPO)• Development of a Design Guideline for Selecting Optimum Rebar
Materials in Concrete Bridge Decks• Evaluation of NDE Technologies for High Strength Wire Corrosion
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
One-Coat SystemsOne-Coat Systems1. 3-coat control (Organic Zn + Epoxy + Polyurethane)2. 2-coat control (MCU-Zn + Polyaspartic)3. Polyaspartic (ASP)4. Epoxy Mastic (EM)5. Calcium Sulfonate Alkyd (CSA)6. Glass Flake Polyester (GFP)7. High Build Acrylic (HBAC)8. Waterborne Epoxy (WBEP)9. Polysiloxane (SLX)10. Urethane Mastic (UM)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Test PanelsTest Panels
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Outdoor Exposure TestingOutdoor Exposure Testing
Periodic performance evaluation every six months
TFHRC, VA Sea Isle City, NJ
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Comparative PhotographsComparative Photographs
3-coat (6,840) 2-coat (6,840) CSA (6,840) GFP (6,840) EM (6,840)
HBAC (5,040) WBEP (5,040) ASP (4,320) SLX (4,320) UM (4,320)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Current Research ProgramsCurrent Research ProgramsCoatingsCoatings• Performance Evaluation of One-Coat Systems• Exploration of 100-Year Maintenance-Free Coating Systems• Development of Field Coating Performance Monitoring MethodologyCorrosionCorrosion• Laboratory Evaluation of Corrosion Resistance of Metallic Dowel Bars• Field Performance Monitoring of a Thin Polymer Overlay (TPO)• Development of a Design Guideline for Selecting Optimum Rebar
Materials in Concrete Bridge Decks• Evaluation of NDE Technologies for High Strength Wire Corrosion
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
100-Year Life Coating Systems100-Year Life Coating Systems
1. This is a FHWA in-house study under a Congress mandated High Performance Steel program.
2. Main objective is to identify and evaluate coating materials that can provide 100 years of virtually maintenance-free service life for the steel bridge structures.
3. This study started in November 2008 as a 42-month in-house research project.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Coating Systems SelectedCoating Systems SelectedSystem
Number Category Generic Coating Name
1 Control - Conventional 3-coat Shop System IOZ / Epoxy / Aliphatic Polyurethane
2 Control -3-coat OZ Shop System Zn-rich Epoxy / Epoxy / Aliphatic Polyurethane
3 3-coat Fluoro-Topcoat System MCU Zn / Epoxy / Fluorourethane
4 2-coat Fast Dry Coating Zn-rich Epoxy / Aliphatic Polyurethane
5 2-coat Polysiloxane Inorganic Zinc / Polysiloxane
6 Metallizing (conventional) + Topcoat Thermal Sprayed Zinc / Linear Epoxy
7 Organic Zinc Rich Epoxy (Zinc Flake)/Linear Epoxy Experimental Primer / Topcoat
8 Calcium Sulfonate Alkyd HR Single Coat CSA
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
100-Year Coating Study - Test Panels100-Year Coating Study - Test Panels
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Current Research ProgramsCurrent Research ProgramsCoatingsCoatings• Performance Evaluation of One-Coat Systems• Exploration of 100-Year Maintenance-Free Coating Systems• Development of Field Coating Performance Monitoring MethodologyCorrosionCorrosion• Laboratory Evaluation of Corrosion Resistance of Metallic Dowel Bars• Field Performance Monitoring of a Thin Polymer Overlay (TPO)• Development of a Design Guideline for Selecting Optimum Rebar
Materials in Concrete Bridge Decks• Evaluation of NDE Technologies for High Strength Wire Corrosion
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Field Coating Performance Monitoring Field Coating Performance Monitoring
Golden Gate Bridge, San Francisco, CA
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Field Coating Performance Monitoring Field Coating Performance Monitoring
Octoraro Creek Bridge, Conowingo, MD
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Current Research ProgramsCurrent Research ProgramsCoatingsCoatings• Performance Evaluation of One-Coat Systems• Exploration of 100-Year Maintenance-Free Coating Systems• Development of Field Coating Performance Monitoring MethodologyCorrosionCorrosion• Laboratory Evaluation of Corrosion Resistance of Metallic Dowel Bars• Field Performance Monitoring of a Thin Polymer Overlay (TPO)• Development of a Design Guideline for Selecting Optimum Rebar
Materials in Concrete Bridge Decks• Evaluation of NDE Technologies for High Strength Wire Corrosion
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Concrete Slab Concrete Slab
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Extracted Dowel Bars after 450 Days in ConcreteExtracted Dowel Bars after 450 Days in Concrete
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Current Research ProgramsCurrent Research ProgramsCoatingsCoatings• Performance Evaluation of One-Coat Systems• Exploration of 100-Year Maintenance-Free Coating Systems• Development of Field Coating Performance Monitoring MethodologyCorrosionCorrosion• Laboratory Evaluation of Corrosion Resistance of Metallic Dowel Bars• Field Performance Monitoring of a Thin Polymer Overlay (TPO)• Development of a Design Guideline for Selecting Optimum Rebar
Materials in Concrete Bridge Decks• Evaluation of NDE Technologies for High Strength Wire Corrosion
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Field Monitoring Study of TPOField Monitoring Study of TPO
Black Creek Bridge, New Paltz, NY
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Field Monitoring Study of TPOField Monitoring Study of TPO
-0.350
-0.300
-0.250
-0.200
-0.150
-0.100
-0.050
0.000
Sept. 10, 2008 (lab) Sept. 19, 2008 (fieldinstallation day)
Feb. 26, 2009 (2ndfield measurement)
June 3, 2009 (3rdfield measurement)
Time
Cor
rosi
on P
oten
tial (
V vs
. CSE
)
CR #1
CR #2
CR #3
CR #4
CR #5 (control)
0
100
200
300
400
500
600
700
800
900
Sept. 10, 2008 (lab) Sept. 19, 2008 (fieldinstallation day)
Feb. 26, 2009 (2ndfield measurement)
June 3, 2009 (3rdfield measurement)
Time
Res
ista
nce
(ohm
)
CR #1
CR #2
CR #3
CR #4
CR #5 (control)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Current Research ProgramsCurrent Research ProgramsCoatingsCoatings• Performance Evaluation of One-Coat Systems• Exploration of 100-Year Maintenance-Free Coating Systems• Development of Field Coating Performance Monitoring MethodologyCorrosionCorrosion• Laboratory Evaluation of Corrosion Resistance of Metallic Dowel Bars• Field Performance Monitoring of a Thin Polymer Overlay (TPO)• Development of a Design Guideline for Selecting Optimum Rebar
Materials in Concrete Bridge Decks• Evaluation of NDE Technologies for High Strength Wire Corrosion
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
ObjectivesObjectives
• To determine mean chloride threshold values and time-to-corrosion initiation for twelve types of reinforcing steel materials
• To develop a concrete bridge deck design guideline for use of reinforcing steel materials based on corrosion performance data and life cycle cost analysis.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Reinforcing Steel MaterialsReinforcing Steel Materials
• Twelve types of #5 or #6 reinforcing materials were acquired from 11 sources and they were embedded in eight slabs.
• The rebars were placed in the top and bottom mats.
• Three levels of artificial defects (0.15, 0.5 and 1.0 %) were introduced on ECR, Zbar, and galvanized. EnduraMet 3212
Arminox (2304)112201103Cr129
NX Infrastructure8CMC7
Duracorr6MMFX5
Galvanized 4Zbar3ECR2Black1
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Slab ConfigurationSlab Configuration
[Plan]
Left section Right section
Internal ducts
Transverse bar
Longitudinal bar
[Profile] [Cross-section]
Insulator
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Cross-sectionCross-section
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Concrete CastingConcrete Casting
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Final Experimental SetupFinal Experimental Setup
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Experimental Procedure – Data MeasurementsExperimental Procedure – Data Measurements
1. Galvanic (Mixed) Potential
2. Macro-cell Current Between Top and Bottom Mats ( circuit break)
3. AC Resistance Between Top and Bottom Mats
4. Open Circuit (Corrosion) Potential in the Top Mat
5. Corrosion Rate (Linear Polarization Resistance) in the Top Mat
6. Electrochemical Impedance Spectroscopy
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Experimental Procedure – Chloride DataExperimental Procedure – Chloride Data• As soon as a top mat rebar indicates corrosion initiation, concrete
powder will be collected adjacent locations accessible from the sides.
• Acid-soluble chloride concentration will be determined as a chloride
threshold value.
• This process will be repeated for every rebar in the top mat.
• Average chloride threshold value and its time-to-corrosion initiation
will be determined for the particular rebar material.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Future Studies Related to ReinforcementFuture Studies Related to Reinforcement
• Determination of Time-to-Corrosion Propagation (Lab Study)
• Development of a Bridge Deck Design Guideline
• Field Survey of Representative Bridge Decks Containing Various Rebar Materials
• Full Scale Accelerated Corrosion Testing Using Environmental Chamber and Wheel Loading
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Current Research ProgramsCurrent Research ProgramsCoatingsCoatings• Performance Evaluation of One-Coat Systems• Exploration of 100-Year Maintenance-Free Coating Systems• Development of Field Coating Performance Monitoring MethodologyCorrosionCorrosion• Laboratory Evaluation of Corrosion Resistance of Metallic Dowel Bars• Field Performance Monitoring of a Thin Polymer Overlay (TPO)• Development of a Design Guideline for Selecting Optimum Rebar
Materials in Concrete Bridge Decks• Evaluation of NDE Technologies for High Strength Wire Corrosion
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Corrosion of Post-Tensioned TendonsCorrosion of Post-Tensioned Tendons
After 16 Years, Niles Channel Bridge, Keys, FL (1999)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Corrosion of Post-Tensioned TendonsCorrosion of Post-Tensioned Tendons
After 13 Years, Sunshine Skyway Bridge, Tampa, FL (2000)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
After 6 years, Mid-Bay Bridge, Destin, FL (2000)
Corrosion of Post-Tensioned Tendons
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Corrosion of Ungrouted PT TendonsCorrosion of Ungrouted PT Tendons
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Deterioration of Stay CablesDeterioration of Stay Cables
After 25 years, Luling Bridge, LA (2007)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Deterioration of Suspension Main CablesDeterioration of Suspension Main Cables
Courtesy of Parsons/Maine DOT
After 70 years, Waldo-Hancock Bridge, Maine (2002)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Corroded Post-Tensioned Tendons
Corroded Post-Tensioned Tendons
After 17 years, Varina-Enon Bridge, Richmond, VA (2007)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Laboratory Study of PT Tendon CorrosionLaboratory Study of PT Tendon Corrosion
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Artificial Defects by Saw CutsArtificial Defects by Saw Cuts
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Artificial Defects by Impressed CurrentArtificial Defects by Impressed Current
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Artificial Defects for Internal PT TendonsArtificial Defects for Internal PT Tendons
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
NDE Technologies EvaluatedNDE Technologies Evaluated• Ultrasonic and Sonic Echo/Impulse Response (SE/IR) – Olson
Engineering
• Magnetostrictive Sensor (MsS) Technology for Guided Long-Range Waves - SwRI
• Microwave Thermoreflectometry - Dr. Ralf Arndt
• Remnant Magnetic System/ Post-TechTM CBD System – UT Berlin and Vector Corrosion Technologies
• Magnetic Main Flux Method (MFM) – Tokyo Rope MFG, Inc.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Main Flux Method (MFM)Main Flux Method (MFM)
Tokyo Rope MFG and Carlton Lab at Columbia University
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
MFM on PT Tendons – 1st GenerationMFM on PT Tendons – 1st Generation
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
MFM PrincipleMFM Principle
N Pole S Pole
Area S
Flux φ
Area S’
Flux φ’
Normal Section
Corroded Section
Magnetic Flow磁束
全磁束検出波形
損傷部モデル
損傷部と検出波形サーチコイルSearch Coil
Damage Model
Detecting Wave
Flux
* The absolute value of metallic area can be evaluated by * The absolute value of metallic area can be evaluated by measuring the parameter measuring the parameter ΔΔØØ..
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Magnetic Flux Chart of Specimen AMagnetic Flux Chart of Specimen A
Estimation of Section Loss (%) 0.2 2.0 0.2
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Autopsy Result of Specimen AAutopsy Result of Specimen A
Estimation (%) 99.8 98.0 99.8Actual (%) 99.8 87.6 (16.5 wires) 99.8
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MFM on PT Tendons – 2nd GenerationMFM on PT Tendons – 2nd Generation
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Test ResultsTest Results
88
89
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91
92
93
94
95
96
97
98
99
100
88 89 90 91 92 93 94 95 96 97 98 99 100
Remaining Cross-sectional Area (%)
Rat
e o
f M
agnetic F
lux
(%)
Tendon A - 2 strands cut
Tendon C - 1 strand cut
Tendon C - 1 wire cut
Tendon A - 1 wire cut
Tendon A - 1 wire cut
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Test Results – Linear RegressionTest Results – Linear Regressiony = 0.999x - 0.1935
R2 = 0.9918
88
89
90
91
92
93
94
95
96
97
98
99
100
88 89 90 91 92 93 94 95 96 97 98 99 100
Remaining Cross-sectional Area (%)
Rate
of
Magn
etic F
lux
(%)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Findings - MFMFindings - MFM• MFM was determined to be the most accurate NDE system in terms of
defect location and section loss in the current evaluation study.
• It has a great potential for detecting insidious corrosion as well as
calculation of section loss in the external PT tendons, stay cables, and
suspension cables.
• However, it needs to modify configuration of the magnetizer and
reduce weight of the system in order to be practical in the field.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
ConclusionsConclusions
• None of the NDE systems was able to detect intentional defects in the internal PT tendons.
• Presence of grout in the external PT tendons made propagating signals attenuate significantly and resulted in some NDE technologies ineffective.
• Main Flux Method (MFM) is the most promising technology for external PT tendons, stay cables, and suspension cables.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Next StepsNext Steps
• The MFM will be tried in two bridge structures with known deterioration problems.
• If these field trials yield good results, the MFM will be employed for two or three more bridges in Maine and Florida.
• With successful performance proven in the field trials, a transportation pool fund study will be initiated to deploy this NDE system in various states.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Challenges Ahead of Us…Challenges Ahead of Us…
• We still need to develop innovative NDE technologies to detect corrosion inside PT anchorage zones, internal PT tendons, and pre-tensioned prestressed strands.
• Also, we need to develop reliable monitoring sensors for new and existing structures containing tensioned high-strength wires.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTERTURNER-FAIRBANK HIGHWAY RESEARCH CENTER
Example of Corrosion Potential Data (Assorted Slab)Example of Corrosion Potential Data (Assorted Slab)
-1.000
-0.900
-0.800
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-0.600
-0.500
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0.000
0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480
Time (day)
Potn
etia
l (V
, CSE
)
ECR-0 Zinc clad-0 SS clad (A)-0 SS clad (C)-0
Galvanized-0 SS clad (B)-0 Black-0
Sudden potential shift in the negative direction indicated time to corrosion initiation. For zinc materials (galvanized and zinc-clad), corrosion potential started at negative potentials as expected for active metals.
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