Federal Highway Administration 

(FHWA) Coatings and Corrosion 

Laboratory (CCL):

Ongoing Research on Coatings

Office of Infrastructure Research and Development

FHWA CCL 

October 2023

Frank Jalinoos

Coatings and corrosion lab manager

Long-Term Infrastructure Performance Team 

© USchools / iStock.
CCL Coatings and 

Corrosion Laboratory

Outline

► CCL expertise, mission, and research disciplines.

► CCL current coatings research projects:

 Corrosion performance of metalized coatings over contaminated 

steel substrate.

 Performance of coating systems used for preventive maintenance.

2
CCL Coatings and 

Corrosion Laboratory

Turner-Fairbank 

Highway Research 

Center Expertise ► Structural design and performance. ► Pavement design and evaluation. ► Safety design and operations. ► Human factors analytics. ► Connected vehicle technologies. ► Intelligent transportation systems.

Source: FHWA. 3
CCL Coatings and 

Corrosion Laboratory

Laboratories

Safety

Source: FHWA.

4
CCL Coatings and 

Corrosion Laboratory

CCL Goals

1. Conduct research to discover innovative solutions for the most critical 

materials-related problems that affect durability and serviceability of 

transportation infrastructure.

2. Focus on research that can yield field-applicable results.

3. Make the Nation’s infrastructure safer and last longer by providing useful

research products to stakeholders (e.g., State and local highway 

agencies, industries, and academia).

5
CCL Coatings and 

Corrosion Laboratory

Corrosion Modeling and Simulation

Data sources: 

► Construction 

documents.

► Field assessment.

► Laboratory testing. 

Modeling corrosion:

► Chloride ingress.

► Corrosion initiation and 

propagation.

► Corrosion damage to 

steel and concrete.

6
Source: FHWA.

CCL Current and Recently Completed 

Coatings Research Projects
CCL Coatings and 

Corrosion Laboratory

Recently Completed Coatings Research Projects

► Report on Industry-Recognized Corrosion Prevention Worker 

Certifications Effectiveness Evaluation, as Requested by the 

Senate Report 114-243 and House Report 114-606 (a 

congressionally mandated study) (Becker and Kogler 2019).

► Coating Performance on Existing Steel Bridge 

Superstructures (which focused on coating performance over 

chloride-contaminated substrates) (Liu and Runion 2020).

► Innovative Coating Removal Techniques For Coated Bridge 

Steel (which evaluated the performance of laser versus gritblasting coating removal) (Fitz-Gerald et al. 2019).

8
CCL Coatings and 

Corrosion Laboratory

Coating Performance on 

Existing Steel Bridge 

Superstructures

Source: FHWA (Liu and Runion 2020).

.

9
CCL Coatings and 

Corrosion Laboratory

Coating Performance on Existing Steel Bridge Superstructures 

(Continued)

► Evaluated four coatings over intentionally contaminated surfaces:

 A three-coat system with an inorganic zinc-rich primer.

 A three-coat system with an organic zinc-rich primer.

 A two-coat system with zinc-rich primer with carbon nanotubes and 

urethane topcoat.

 A one-coat system of high-ratio calcium sulfonate alkyd.

► Developed substrates with three levels of chloride contamination:

 Control: less than 1-μg/cm2.

 –20-μg/cm2.

 –60-μg/cm2.

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CCL Coatings and 

Corrosion Laboratory

Outdoor Exposure Testing

All photos source: FHWA.

39

Scribes in coating.

59 30

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CCL Coatings and 

Corrosion Laboratory

Accelerated Lab Testing (ALT)

All photos source: FHWA.

Salt fog chambers Ultraviolet chamber.

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CCL Coatings and 

Corrosion Laboratory

ALT

All photos source: FHWA.

Rust creepage development on ALT panels.

Rust creepage measurement.

13
CCL Coatings and 

Corrosion Laboratory

Coating Performance—Conclusions

► The three-coat systems showed better tolerance of chloride than the twoand one-coat systems. The three-coat system with inorganic zinc primer 

had the best tolerance of chloride.

► The inorganic zinc primer performed slightly better than the organic zinc 

primer with chloride contamination levels up to 60-μg/cm2.

► Spraying saltwater did not affect the performance of the three-coat 

systems. The two-coat panels subjected to saltwater spray developed 

significant rust creepage, whereas the panels exposed to water spray did 

not exhibit noticeable creepage.

► Outdoor weathering simulates the natural exposure conditions 

experienced by steel bridges in service. However, the testing time should 

be significantly longer than ALT.

14
CCL Coatings and 

Corrosion Laboratory

Current Coatings Research Projects

► Corrosion performance of metalized coatings over 

contaminated steel substrate (metalizing/galvanizing 

performance over chloride-contaminated substrate). 

► Performance of coating systems used for preventive 

maintenance.

15
CCL Coatings and 

Corrosion Laboratory

Corrosion Performance of Metalized 

Coatings Over Contaminated 

Steel Substrate

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CCL Coatings and 

Corrosion Laboratory

Corrosion Performance of Metalized Coatings 

Over Contaminated Steel Substrate 

(Continued)

► Evaluate the performance of thermal spray coatings on contaminated 

steel substrates.

► Evaluate three coating types (i.e., zinc, aluminum, and zinc/aluminum 

(85-percent zinc and 15-percent aluminum)) over four levels of chloride 

contamination: 0-, 20-, 60-, and 100-μg/cm2.

► Coat the specimens with a top sealer.

► Stripe coat the edges with a seal coating.

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CCL Coatings and 

Corrosion Laboratory

Metallization

All photos source: FHWA.

Thermal spray operation.

007

Panel coated with top sealer.

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CCL Coatings and 

Corrosion Laboratory

Metalized Coatings—Testing (1/3)

All photos source: FHWA.

Outdoor exposure. Panels in salt-fog chamber.

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CCL Coatings and 

Corrosion Laboratory

Metalized Coatings—Testing (2/3)

003

All photos source: FHWA.

Aluminum coated.

171

Aluminum coated.

199

Zinc coated.

227

Aluminum-zinc coated.

Coated panels after 10 ALT cycles.

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CCL Coatings and 

Corrosion Laboratory

Metalized Coatings—Testing (3/3)

309 225 311 310

All photos source: FHWA.

Aluminum-zinc-coated panels showing coating failure after 10 ALT

cycles.

21
CCL Coatings and 

Corrosion Laboratory

Coating Film Damaged by Corrosion (1/3)

Source: FHWA.

Zinc-coated panels after accelerated lab testing showing coating layer 

loss (panel number 029).

22
CCL Coatings and 

Corrosion Laboratory

Coating Film Damaged by Corrosion (2/3)

Source: FHWA.

Aluminum-zinc-alloy-coated panels after accelerated lab testing showing 

coating layer loss (panel number 225).

23
CCL Coatings and 

Corrosion Laboratory

Coating Film Damaged by Corrosion (3/3)

Source: FHWA.

Aluminum-coated panels after accelerated lab testing showing coating 

layer loss (panel number 001).

24
CCL Coatings and 

Corrosion Laboratory

Performance of 

Preventive Maintenance Coatings

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CCL Coatings and 

Corrosion Laboratory

Scope of Study:

► Explore new and advanced coating materials for preventive maintenance 

and condition-based preservations.

► Evaluate novel surface cleaning methods that are field deployable (e.g., 

laser ablation).

► Explore field applications for maintenance coating.

► Evaluate the long-term performance of coating systems.

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CCL Coatings and 

Corrosion Laboratory

Advanced Coatings for Preventive Maintenance

1. Single-component organic zinc coating: one-coat system 

containing 96-percent zinc in dry film.

2. Graphene-enhanced primer plus urethane topcoat: increased 

barrier performance in the primer.

3. Epoxy zinc-rich primer plus urethane topcoat: two-coat 

system with improved corrosion resistance. 

4. Duplex coating system: metallizing plus durable organic 

coating.

27
CCL Coatings and 

Corrosion Laboratory

Laser Ablation for Surface Preparation

► Aims nanosecond-length pulses of laser light towards a 

surface (Adapt Laser n.d.).

► Turns contaminants or coating particles into a gas or peels 

them from the surface (Adapt Laser n.d.).

► Has benefits for surface preparation (Fitz-Gerald et al. 2019):

 Is easy to operate (easily automated, quiet, and reliable).

 Does not require surface cleanup.

 Does not require containment. 

 Is safe and environmentally friendly. 

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CCL Coatings and 

Corrosion Laboratory

Laser Ablation for Surface Preparation 

(Continued)

All photos source: FHWA.

Before. After.

Laser ablation for coating removal and surface preparation.

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CCL Coatings and 

Corrosion Laboratory

Coating Systems: Single Coat

Minimal 

Surface 

Preparation

Zinc 

Provides 

Cathodic 

(Sacrificial) 

Protection

Durable 

Coating

for 

Maintenance

All images source: FHWA.

Single-component organic zinc coating.

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CCL Coatings and 

Corrosion Laboratory

Coating Systems: Two Coat

Laser 

Ablation

Nano 

Materials

Adequate 

Adhesion

and

Durability

All images source: FHWA.

• Zinc-rich primer.

• Graphene-enhanced primer.

• Laser-ablated steel surface.

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CCL Coatings and 

Corrosion Laboratory

Coating Systems: Duplex Coatings

Metalizing 

on Abrasive 

Blasted 

Surface

Top

Coat

Duplex 

Coating

All images source: FHWA.

• The thermal spray (metalizing) zinc coating is on the 

abrasive blasted steel substrate.

• The topcoat provides extra barrier protection.

32
CCL Coatings and 

Corrosion Laboratory

CCL Web Page

https://highways.dot.gov/research/laboratories/coatings-corrosion-laboratory/publications (FHWA n.d.)

Google® search: “FHWA Corrosion Lab”

© 2020 Google. 

Search FHWA site

Explore Research and 

Technology

Coatings and Corrosion 

Laboratory Overview

Laboratories Overview

Projects

Publications

Source: FHWA (FHWA n.d.). 

.

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CCL Coatings and 

Corrosion Laboratory

References

Adapt Laser. n.d. “How Laser Cleaning Works” (web page). https://adapt-laser.com/how-laser-cleaning-works, last accessed 

March 28th, 2023.

Becker, D. R., and R. A. Kogler. 2019. Report on Industry-Recognized Corrosion Prevention Worker Certifications Effectiveness 

Evaluation, as Requested by the Senate Report 114-243 and House Report 114-606. Washington, DC: Federal Highway 

Administration.

FHWA. n.d. “Corrosion and Publications.” (web page). https://highways.dot.gov/research/laboratories/coatings-corrosionlaboratory/corrosion-coating-publications, last accessed October 21, 2021.

Fitz-Gerald, J. M., S. R. Agnew, W. Moffat, S. R. Sharp, J. S. Gillespie, D. R. Becker, R. Liu, and A. W. Runion, Jr. 2019. 

Innovative Coating Removal Techniques for Coated Bridge Steel. FHWA/VTRC 20-R1. Washington, DC: Federal Highway 

Administration.

Liu, R., and A. W. Runion, Jr. 2020. Coating Performance on Existing Steel Bridge Superstructures. Report No. FHWA-HRT-20-

065. Washington, DC: Federal Highway Administration. 

https://www.fhwa.dot.gov/publications/research/infrastructure/structures/bridge/20065/20065.pdf.

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© Peeterv / iStock.

CCL Coatings and 

Corrosion Laboratory

Contact

Frank Jalinoos

frank.jalinoos@dot.gov

35
CCL Coatings and 

Corrosion Laboratory

Disclaimer

The U.S. Government does not endorse products or manufacturers. Trademarks 

or manufacturers’ names appear in this presentation only because they are 

considered essential to the objective of the presentation. They are included for 

informational purposes only and are not intended to reflect a preference, 

approval, or endorsement of any one product or entity.

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