Overview of FHWA Current Coatings and Corrosion Research ...
Overview of FHWA Current Coatings and Corrosion Research ...
Overview of FHWA Current Coatings and Corrosion Research ...
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TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Overview</strong> <strong>of</strong> <strong>FHWA</strong> <strong>Current</strong> <strong>Coatings</strong> <strong>and</strong><br />
<strong>Corrosion</strong> <strong>Research</strong> Programs<br />
Seung-Kyoung Lee<br />
Manager <strong>of</strong> <strong>Coatings</strong> <strong>and</strong> <strong>Corrosion</strong> Laboratory<br />
Office <strong>of</strong> Infrastructure R&D<br />
Turner-Fairbank Highway <strong>Research</strong> Center<br />
Federal Highway Administration<br />
AASHTO Bridge 2009, New Orleans, July 6, 2009
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Coatings</strong><br />
<strong>Current</strong> <strong>Research</strong> Programs<br />
• Performance Evaluation <strong>of</strong> One-Coat Systems<br />
• Exploration <strong>of</strong> 100-Year Maintenance-Free Coating Systems<br />
• Development <strong>of</strong> Field Coating Performance Monitoring Methodology<br />
<strong>Corrosion</strong><br />
• Laboratory Evaluation <strong>of</strong> <strong>Corrosion</strong> Resistance <strong>of</strong> Metallic Dowel Bars<br />
• Field Performance Monitoring <strong>of</strong> a Thin Polymer Overlay (TPO)<br />
• Development <strong>of</strong> a Design Guideline for Selecting Optimum Rebar<br />
Materials in Concrete Bridge Decks<br />
• Evaluation <strong>of</strong> NDE Technologies for High Strength Wire <strong>Corrosion</strong>
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Coatings</strong><br />
<strong>Current</strong> <strong>Research</strong> Programs<br />
• Performance Evaluation <strong>of</strong> One-Coat Systems<br />
• Exploration <strong>of</strong> 100-Year Maintenance-Free Coating Systems<br />
• Development <strong>of</strong> Field Coating Performance Monitoring Methodology<br />
<strong>Corrosion</strong><br />
• Laboratory Evaluation <strong>of</strong> <strong>Corrosion</strong> Resistance <strong>of</strong> Metallic Dowel Bars<br />
• Field Performance Monitoring <strong>of</strong> a Thin Polymer Overlay (TPO)<br />
• Development <strong>of</strong> a Design Guideline for Selecting Optimum Rebar<br />
Materials in Concrete Bridge Decks<br />
• Evaluation <strong>of</strong> NDE Technologies for High Strength Wire <strong>Corrosion</strong>
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
One-Coat Systems<br />
1. 3-coat control (Organic Zn + Epoxy + Polyurethane)<br />
2. 2-coat control (MCU-Zn + Polyaspartic)<br />
3. Polyaspartic (ASP)<br />
4. Epoxy Mastic (EM)<br />
5. Calcium Sulfonate Alkyd (CSA)<br />
6. Glass Flake Polyester (GFP)<br />
7. High Build Acrylic (HBAC)<br />
8. Waterborne Epoxy (WBEP)<br />
9. Polysiloxane (SLX)<br />
10. Urethane Mastic (UM)
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Test Panels
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Outdoor Exposure Testing<br />
TFHRC, VA<br />
Sea Isle City, NJ<br />
Periodic performance evaluation every six months
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Comparative Photographs<br />
3-coat (6,840) 2-coat (6,840) CSA (6,840) GFP (6,840) EM (6,840)<br />
HBAC (5,040) WBEP (5,040) ASP (4,320) SLX (4,320) UM (4,320)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Coatings</strong><br />
<strong>Current</strong> <strong>Research</strong> Programs<br />
• Performance Evaluation <strong>of</strong> One-Coat Systems<br />
• Exploration <strong>of</strong> 100-Year Maintenance-Free Coating Systems<br />
• Development <strong>of</strong> Field Coating Performance Monitoring Methodology<br />
<strong>Corrosion</strong><br />
• Laboratory Evaluation <strong>of</strong> <strong>Corrosion</strong> Resistance <strong>of</strong> Metallic Dowel Bars<br />
• Field Performance Monitoring <strong>of</strong> a Thin Polymer Overlay (TPO)<br />
• Development <strong>of</strong> a Design Guideline for Selecting Optimum Rebar<br />
Materials in Concrete Bridge Decks<br />
• Evaluation <strong>of</strong> NDE Technologies for High Strength Wire <strong>Corrosion</strong>
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
100-Year Life Coating Systems<br />
1. This is a <strong>FHWA</strong> in-house study under a Congress<br />
m<strong>and</strong>ated High Performance Steel program.<br />
2. Main objective is to identify <strong>and</strong> evaluate coating materials<br />
that can provide 100 years <strong>of</strong> virtually maintenance-free<br />
service life for the steel bridge structures.<br />
3. This study started in November 2008 as a 42-month inhouse<br />
research project.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Coating Systems Selected<br />
System<br />
Number<br />
Category<br />
Generic Coating Name<br />
1 Control - Conventional 3-coat Shop System IOZ / Epoxy / Aliphatic Polyurethane<br />
2 Control -3-coat OZ Shop System Zn-rich Epoxy / Epoxy / Aliphatic Polyurethane<br />
3 3-coat Fluoro-Topcoat System MCU Zn / Epoxy / Fluorourethane<br />
4 2-coat Fast Dry Coating Zn-rich Epoxy / Aliphatic Polyurethane<br />
5 2-coat Polysiloxane Inorganic Zinc / Polysiloxane<br />
6 Metallizing (conventional) + Topcoat Thermal Sprayed Zinc / Linear Epoxy<br />
7 Organic Zinc Rich Epoxy (Zinc Flake)/Linear Epoxy Experimental Primer / Topcoat<br />
8 Calcium Sulfonate Alkyd HR Single Coat CSA
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
100-Year Coating Study - Test Panels
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Coatings</strong><br />
<strong>Current</strong> <strong>Research</strong> Programs<br />
• Performance Evaluation <strong>of</strong> One-Coat Systems<br />
• Exploration <strong>of</strong> 100-Year Maintenance-Free Coating Systems<br />
• Development <strong>of</strong> Field Coating Performance Monitoring Methodology<br />
<strong>Corrosion</strong><br />
• Laboratory Evaluation <strong>of</strong> <strong>Corrosion</strong> Resistance <strong>of</strong> Metallic Dowel Bars<br />
• Field Performance Monitoring <strong>of</strong> a Thin Polymer Overlay (TPO)<br />
• Development <strong>of</strong> a Design Guideline for Selecting Optimum Rebar<br />
Materials in Concrete Bridge Decks<br />
• Evaluation <strong>of</strong> NDE Technologies for High Strength Wire <strong>Corrosion</strong>
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Field Coating Performance Monitoring<br />
Golden Gate Bridge, San Francisco, CA
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Field Coating Performance Monitoring<br />
Octoraro Creek Bridge, Conowingo, MD
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Coatings</strong><br />
<strong>Current</strong> <strong>Research</strong> Programs<br />
• Performance Evaluation <strong>of</strong> One-Coat Systems<br />
• Exploration <strong>of</strong> 100-Year Maintenance-Free Coating Systems<br />
• Development <strong>of</strong> Field Coating Performance Monitoring Methodology<br />
<strong>Corrosion</strong><br />
• Laboratory Evaluation <strong>of</strong> <strong>Corrosion</strong> Resistance <strong>of</strong> Metallic Dowel Bars<br />
• Field Performance Monitoring <strong>of</strong> a Thin Polymer Overlay (TPO)<br />
• Development <strong>of</strong> a Design Guideline for Selecting Optimum Rebar<br />
Materials in Concrete Bridge Decks<br />
• Evaluation <strong>of</strong> NDE Technologies for High Strength Wire <strong>Corrosion</strong>
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Concrete Slab
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Extracted Dowel Bars after 450 Days in Concrete
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Coatings</strong><br />
<strong>Current</strong> <strong>Research</strong> Programs<br />
• Performance Evaluation <strong>of</strong> One-Coat Systems<br />
• Exploration <strong>of</strong> 100-Year Maintenance-Free Coating Systems<br />
• Development <strong>of</strong> Field Coating Performance Monitoring Methodology<br />
<strong>Corrosion</strong><br />
• Laboratory Evaluation <strong>of</strong> <strong>Corrosion</strong> Resistance <strong>of</strong> Metallic Dowel Bars<br />
• Field Performance Monitoring <strong>of</strong> a Thin Polymer Overlay (TPO)<br />
• Development <strong>of</strong> a Design Guideline for Selecting Optimum Rebar<br />
Materials in Concrete Bridge Decks<br />
• Evaluation <strong>of</strong> NDE Technologies for High Strength Wire <strong>Corrosion</strong>
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Field Monitoring Study <strong>of</strong> TPO<br />
Black Creek Bridge, New Paltz, NY
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Field Monitoring Study <strong>of</strong> TPO<br />
0.000<br />
900<br />
<strong>Corrosion</strong> Potential (V vs. CSE)<br />
-0.050<br />
-0.100<br />
-0.150<br />
-0.200<br />
-0.250<br />
CR #1<br />
CR #2<br />
CR #3<br />
CR #4<br />
CR #5 (control)<br />
Resistance (ohm)<br />
800<br />
700<br />
600<br />
500<br />
400<br />
300<br />
200<br />
CR #1<br />
CR #2<br />
CR #3<br />
CR #4<br />
CR #5 (control)<br />
-0.300<br />
100<br />
-0.350<br />
Sept. 10, 2008 (lab)<br />
Sept. 19, 2008 (field<br />
installation day)<br />
Time<br />
Feb. 26, 2009 (2nd<br />
field measurement)<br />
June 3, 2009 (3rd<br />
field measurement)<br />
0<br />
Sept. 10, 2008 (lab)<br />
Sept. 19, 2008 (field<br />
installation day)<br />
Time<br />
Feb. 26, 2009 (2nd<br />
field measurement)<br />
June 3, 2009 (3rd<br />
field measurement)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Coatings</strong><br />
<strong>Current</strong> <strong>Research</strong> Programs<br />
• Performance Evaluation <strong>of</strong> One-Coat Systems<br />
• Exploration <strong>of</strong> 100-Year Maintenance-Free Coating Systems<br />
• Development <strong>of</strong> Field Coating Performance Monitoring Methodology<br />
<strong>Corrosion</strong><br />
• Laboratory Evaluation <strong>of</strong> <strong>Corrosion</strong> Resistance <strong>of</strong> Metallic Dowel Bars<br />
• Field Performance Monitoring <strong>of</strong> a Thin Polymer Overlay (TPO)<br />
• Development <strong>of</strong> a Design Guideline for Selecting Optimum Rebar<br />
Materials in Concrete Bridge Decks<br />
• Evaluation <strong>of</strong> NDE Technologies for High Strength Wire <strong>Corrosion</strong>
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Objectives<br />
• To determine mean chloride threshold values <strong>and</strong> timeto-corrosion<br />
initiation for twelve types <strong>of</strong> reinforcing steel<br />
materials<br />
• To develop a concrete bridge deck design guideline for<br />
use <strong>of</strong> reinforcing steel materials based on corrosion<br />
performance data <strong>and</strong> life cycle cost analysis.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Reinforcing Steel Materials<br />
• Twelve types <strong>of</strong> #5 or #6 reinforcing<br />
materials were acquired from 11 sources<br />
<strong>and</strong> they were embedded in eight slabs.<br />
• The rebars were placed in the top <strong>and</strong><br />
bottom mats.<br />
• Three levels <strong>of</strong> artificial defects (0.15, 0.5<br />
<strong>and</strong> 1.0 %) were introduced on ECR, Zbar,<br />
Arminox (2304)<br />
<strong>and</strong> galvanized. 12 EnduraMet 32<br />
1<br />
2<br />
3<br />
4<br />
5<br />
6<br />
7<br />
8<br />
9<br />
10<br />
11<br />
Black<br />
ECR<br />
Zbar<br />
Galvanized<br />
MMFX<br />
Duracorr<br />
CMC<br />
NX Infrastructure<br />
3Cr12<br />
2201
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Slab Configuration<br />
Transverse bar<br />
Left section<br />
Right section<br />
Longitudinal bar<br />
Internal ducts<br />
[Plan]<br />
Insulator<br />
[Pr<strong>of</strong>ile]<br />
[Cross-section]
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<strong>Overview</strong>
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Cross-section
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Concrete Casting
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Final Experimental Setup
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Experimental Procedure – Data Measurements<br />
1. Galvanic (Mixed) Potential<br />
2. Macro-cell <strong>Current</strong> Between Top <strong>and</strong> Bottom Mats ( circuit break)<br />
3. AC Resistance Between Top <strong>and</strong> Bottom Mats<br />
4. Open Circuit (<strong>Corrosion</strong>) Potential in the Top Mat<br />
5. <strong>Corrosion</strong> Rate (Linear Polarization Resistance) in the Top Mat<br />
6. Electrochemical Impedance Spectroscopy
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Experimental Procedure – Chloride Data<br />
• As soon as a top mat rebar indicates corrosion initiation, concrete<br />
powder will be collected adjacent locations accessible from the sides.<br />
• Acid-soluble chloride concentration will be determined as a chloride<br />
threshold value.<br />
• This process will be repeated for every rebar in the top mat.<br />
• Average chloride threshold value <strong>and</strong> its time-to-corrosion initiation<br />
will be determined for the particular rebar material.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Future Studies Related to Reinforcement<br />
• Determination <strong>of</strong> Time-to-<strong>Corrosion</strong> Propagation (Lab Study)<br />
• Development <strong>of</strong> a Bridge Deck Design Guideline<br />
• Field Survey <strong>of</strong> Representative Bridge Decks Containing<br />
Various Rebar Materials<br />
• Full Scale Accelerated <strong>Corrosion</strong> Testing Using Environmental<br />
Chamber <strong>and</strong> Wheel Loading
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Coatings</strong><br />
<strong>Current</strong> <strong>Research</strong> Programs<br />
• Performance Evaluation <strong>of</strong> One-Coat Systems<br />
• Exploration <strong>of</strong> 100-Year Maintenance-Free Coating Systems<br />
• Development <strong>of</strong> Field Coating Performance Monitoring Methodology<br />
<strong>Corrosion</strong><br />
• Laboratory Evaluation <strong>of</strong> <strong>Corrosion</strong> Resistance <strong>of</strong> Metallic Dowel Bars<br />
• Field Performance Monitoring <strong>of</strong> a Thin Polymer Overlay (TPO)<br />
• Development <strong>of</strong> a Design Guideline for Selecting Optimum Rebar<br />
Materials in Concrete Bridge Decks<br />
• Evaluation <strong>of</strong> NDE Technologies for High Strength Wire <strong>Corrosion</strong>
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Corrosion</strong> <strong>of</strong> Post-Tensioned Tendons<br />
After 16 Years, Niles Channel Bridge, Keys, FL (1999)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Corrosion</strong> <strong>of</strong> Post-Tensioned Tendons<br />
After 13 Years, Sunshine Skyway Bridge, Tampa, FL (2000)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Corrosion</strong> <strong>of</strong> Post-Tensioned Tendons<br />
After 6 years, Mid-Bay Bridge, Destin, FL (2000)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
<strong>Corrosion</strong> <strong>of</strong> Ungrouted PT Tendons
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Deterioration <strong>of</strong> Stay Cables<br />
After 25 years, Luling Bridge, LA (2007)
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Deterioration <strong>of</strong> Suspension Main Cables<br />
Courtesy <strong>of</strong> Parsons/Maine DOT<br />
After 70 years, Waldo-Hancock Bridge, Maine (2002)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Corroded<br />
Post-Tensioned Tendons<br />
After 17 years, Varina-Enon Bridge, Richmond, VA (2007)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Laboratory Study <strong>of</strong> PT Tendon <strong>Corrosion</strong>
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Artificial Defects by Saw Cuts
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Artificial Defects by Impressed <strong>Current</strong>
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Artificial Defects for Internal PT Tendons
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NDE Technologies Evaluated<br />
• Ultrasonic <strong>and</strong> Sonic Echo/Impulse Response (SE/IR) – Olson<br />
Engineering<br />
• Magnetostrictive Sensor (MsS) Technology for Guided Long-Range<br />
Waves - SwRI<br />
• Microwave Thermoreflectometry - Dr. Ralf Arndt<br />
• Remnant Magnetic System/ Post-Tech TM CBD System – UT Berlin <strong>and</strong><br />
Vector <strong>Corrosion</strong> Technologies<br />
• Magnetic Main Flux Method (MFM) – Tokyo Rope MFG, Inc.
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Main Flux Method (MFM)<br />
Tokyo Rope MFG <strong>and</strong> Carlton Lab at Columbia University
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MFM on PT Tendons – 1 st Generation
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MFM Principle<br />
N Pole<br />
Magnetic Flow<br />
S Pole<br />
Search<br />
サーチコイル<br />
Coil<br />
Flux 磁 束<br />
損 傷 部 と 検 出 波 形<br />
Area S<br />
Flux φ<br />
Normal<br />
Section<br />
Area S’<br />
Flux φ’<br />
Corroded<br />
Section<br />
Damage<br />
損 傷 部 モデル<br />
Model<br />
Detecting<br />
全 磁 束 検 出 波 形<br />
Wave<br />
* The absolute value <strong>of</strong> metallic area can be evaluated by<br />
measuring the parameter ΔØ.
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Magnetic Flux Chart <strong>of</strong> Specimen A<br />
Estimation <strong>of</strong><br />
Section Loss (%)<br />
0.2 2.0 0.2
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Autopsy Result <strong>of</strong> Specimen A<br />
Estimation (%) 99.8 98.0 99.8<br />
Actual (%) 99.8 87.6 (16.5 wires) 99.8
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MFM on PT Tendons – 2 nd Generation
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Test Results<br />
100<br />
99<br />
98<br />
97<br />
Tendon C - 1 wire cut<br />
Rate <strong>of</strong> Magnetic Flux (%)<br />
96<br />
95<br />
94<br />
93<br />
92<br />
Tendon C - 1 str<strong>and</strong> cut<br />
Tendon A - 1 wire cut<br />
91<br />
90<br />
Tendon A - 2 str<strong>and</strong>s cut<br />
Tendon A - 1 wire cut<br />
89<br />
88<br />
88 89 90 91 92 93 94 95 96 97 98 99 100<br />
Remaining Cross-sectional Area (%)
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Test Results – Linear Regression<br />
100<br />
99<br />
98<br />
y = 0.999x - 0.1935<br />
R 2 = 0.9918<br />
Rate <strong>of</strong> Magnetic Flux (%)<br />
97<br />
96<br />
95<br />
94<br />
93<br />
92<br />
91<br />
90<br />
89<br />
88<br />
88 89 90 91 92 93 94 95 96 97 98 99 100<br />
Remaining Cross-sectional Area (%)
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Findings -MFM<br />
• MFM was determined to be the most accurate NDE system in terms <strong>of</strong><br />
defect location <strong>and</strong> section loss in the current evaluation study.<br />
• It has a great potential for detecting insidious corrosion as well as<br />
calculation <strong>of</strong> section loss in the external PT tendons, stay cables, <strong>and</strong><br />
suspension cables.<br />
• However, it needs to modify configuration <strong>of</strong> the magnetizer <strong>and</strong><br />
reduce weight <strong>of</strong> the system in order to be practical in the field.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Conclusions<br />
• None <strong>of</strong> the NDE systems was able to detect intentional<br />
defects in the internal PT tendons.<br />
• Presence <strong>of</strong> grout in the external PT tendons made<br />
propagating signals attenuate significantly <strong>and</strong> resulted in<br />
some NDE technologies ineffective.<br />
• Main Flux Method (MFM) is the most promising technology for<br />
external PT tendons, stay cables, <strong>and</strong> suspension cables.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Next Steps<br />
• The MFM will be tried in two bridge structures with known<br />
deterioration problems.<br />
• If these field trials yield good results, the MFM will be<br />
employed for two or three more bridges in Maine <strong>and</strong> Florida.<br />
• With successful performance proven in the field trials, a<br />
transportation pool fund study will be initiated to deploy this<br />
NDE system in various states.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Challenges Ahead <strong>of</strong> Us…<br />
• We still need to develop innovative NDE technologies to<br />
detect corrosion inside PT anchorage zones, internal PT<br />
tendons, <strong>and</strong> pre-tensioned prestressed str<strong>and</strong>s.<br />
• Also, we need to develop reliable monitoring sensors for<br />
new <strong>and</strong> existing structures containing tensioned highstrength<br />
wires.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Thank You.
TURNER-FAIRBANK HIGHWAY RESEARCH CENTER<br />
Example <strong>of</strong> <strong>Corrosion</strong> Potential Data (Assorted Slab)<br />
Potnetial (V, CSE)<br />
0.000<br />
-0.100<br />
-0.200<br />
-0.300<br />
-0.400<br />
-0.500<br />
-0.600<br />
-0.700<br />
-0.800<br />
-0.900<br />
-1.000<br />
ECR-0 Zinc clad-0 SS clad (A)-0 SS clad (C)-0<br />
Galvanized-0 SS clad (B)-0 Black-0<br />
0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480<br />
Time (day)<br />
Sudden potential shift in the negative direction indicated time to corrosion initiation. For zinc materials<br />
(galvanized <strong>and</strong> zinc-clad), corrosion potential started at negative potentials as expected for active metals.
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