Textured Epoxy Coating for Rebar: Performance, Benefits, and Applications
KEY TAKEAWAYS
- Restores concrete bond. Texturing re-establishes the mechanical interlock that a smooth coating gives up, producing bond and lap-splice capacities comparable to uncoated bar.
- Governed by ASTM A1124. A1124/A1124M standardizes surface preparation, dual-coat application, total film thickness, texture roughness, and bend flexibility.
- Monolithic dual-coat chemistry. The texturizing layer is applied while the A775 base coat is still molten, so the two layers gel, cure, and cross-link into a single coating system.
- Better crack and damage control. University research reports roughly a one-third reduction in total cracked area and half-width crack openings, alongside substantially lower handling damage than smooth green bar.
- Growing field adoption. Specified for Illinois DOT bridge decks, Wisconsin DOT’s I-39 comparison deck, and the Sherwin-Williams headquarters in Cleveland.
What Is Textured Epoxy Coating?
For more than 50 years, epoxy-coated reinforcing bars conforming to ASTM A775 have served as North America’s primary corrosion-protection system for concrete infrastructure.2 Fusion-bonded epoxy (FBE) provides a dielectric barrier that isolates the steel from moisture, oxygen, and chloride ions carried by deicing salts and seawater. That barrier performance is well documented and is not in question. What conventional epoxy coating does give up is surface friction: a smooth coating reduces the mechanical interaction between the bar surface and the surrounding concrete.
Textured epoxy coating is a dual-coat system designed to recover that mechanical interaction while preserving the proven barrier. It is governed by ASTM A1124/A1124M, which sets requirements for surface preparation, dual-coat application, total coating thickness, texture roughness, and bend flexibility.1
Manufacturing is a two-step electrostatic process. Heated reinforcing bar first receives a standard ASTM A775 fusion-bonded epoxy base coat. While that layer is still molten, a second textured epoxy layer is applied over it. The two layers gel and cure simultaneously and chemically bond to one another during curing, forming a single cross-linked coating system rather than two stacked films. The result is a finished 1, 9ASTM A1124 technology page covers the process in more detail.
How Textured Epoxy Coating Improves on Standard Epoxy Coated Rebar
Engineers evaluate reinforcement on three practical measures: bond and development behavior, tolerance of jobsite handling, and long-term corrosion resistance. Textured epoxy coating is aimed squarely at the first two while leaving the third untouched.
1. Restoring Concrete Bond and Addressing Splice Penalties
Because smooth epoxy coating reduces surface friction, design codes apply a coating modification factor to development and splice lengths — 1.5 where cover is less than 3 bar diameters or clear spacing is less than 6 bar diameters, and 1.2 for all other cases.3 Longer splices add steel weight, increase cost, and contribute to congestion in heavily reinforced decks and caps.
Texturing restores mechanical anchorage. Beam-end testing (ASTM A944) at the University of Kansas measured relative bond strength ratios of roughly 0.97 to 1.00 for textured bars compared with uncoated steel. Full-scale lap splice testing found textured bars averaged about 1.05 times the splice strength of uncoated bar, against roughly 0.83 for smooth epoxy-coated bar.4 The University of Kansas report documents the test program.
A note on code status: this research supports bond parity with uncoated bar, but the coating modification factors in the governing design codes have not yet been revised for A1124 material. Work to reference ASTM A1124 in the AASHTO LRFD Bridge Design and Construction Specifications is in progress. Designers should confirm the factors required by the owner agency’s current specification for any given project.
2. Enhanced Damage Tolerance and Chip Resistance
Jobsite handling — bundling, lifting, dragging across a deck, and tying — is where coated bar is most likely to be damaged, and every chip is a potential holiday in the barrier. In gravelometer bombardment testing (ASTM D3170) and drop testing, the textured surface acted as a sacrificial wear layer over the A775 base coat, producing substantially fewer chips per specimen than smooth coated bar.1, 9 Practically, that means less field patching and fewer rejected bundles.
3. Uncompromised Barrier Protection
The base layer complies fully with ASTM A775, including chemical resistance (ASTM G20), cathodic disbondment (ASTM G8), and salt-spray exposure (ASTM B117).2, 9 Because the corrosion barrier is unchanged, textured epoxy coating delivers the same dielectric protection engineers already specify with green bar. Cured fusion-bonded epoxy is chemically stable and non-reactive in the alkaline concrete environment and requires no chromate passivation or admixtures to prevent bond-reducing reactions during curing.
Research and Testing Results
Independent research programs at several universities and state agencies have evaluated textured epoxy coating:
- University of Kansas — Established lap-splice capacity averaging approximately 1.05 times that of uncoated bar in full-scale testing, with beam-end bond ratios near parity.4 Read the report
- University of Illinois Urbana-Champaign — Digital image correlation showed concrete reinforced with textured epoxy bar developed cracks roughly half as wide as those with smooth coated bar, with about a one-third reduction in total cracked surface area and markedly greater slip resistance.5, 9 Read the study
- Wisconsin DOT — WHRP research examined bond and splice behavior and the resulting effect on required lap lengths relative to smooth epoxy-coated bar.6, 9 Read the report
- Clemson University — Flexural testing evaluated crack-control performance across coating types, with textured bar performing favorably against the tested average.7, 9
- Illinois DOT — Following the UIUC work, IDOT moved textured epoxy-coated bar into state bridge deck construction.8
A broader summary of the research base appeared in ASPIRE magazine, and EIG has published a short video overview of why bond improves.
Applications for Textured Epoxy-Coated Rebar
Horizontal Infrastructure: Bridges and Pavements
Bridge decks, continuously reinforced concrete pavement, approach slabs, and marine substructures are the primary market for ASTM A1124 bar. These are the elements that see the most direct chloride loading, and they are also where crack width governs how quickly chlorides reach the steel. Keeping cracks narrow and reducing splice length requirements both support the 75- to 100-year service life targets transportation agencies are now setting.
Vertical and Commercial Construction
High-rise balconies, coastal and multi-level parking structures, and exposed slabs are adopting textured epoxy coating for the same reasons. Parking decks that carry deicing salt in on vehicle tires are among the most aggressive chloride environments in commercial construction, and reduced cracking translates directly into less spalling and less repair.
Seismic and Cyclic Loading
Under reversed cyclic loading, bond quality governs how well a member dissipates energy without pullout or slip. Improved mechanical anchorage is meaningful in these details. The Sherwin-Williams headquarters in Cleveland, Ohio, is the first commercial building constructed with textured epoxy-coated reinforcement.9
How the Epoxy Interest Group Supports Specification
As the industry association for epoxy-coated reinforcement, the Epoxy Interest Group provides technical guidance for engineers, specifiers, and DOT materials bureaus evaluating ASTM A1124. EIG offers research summaries, specification language, and information on applicator plant certification. Engineers looking for built work can review documented project examples spanning bridges, parking structures, and marine environments.
Final Thoughts
Textured epoxy coating pairs the chemical durability of traditional green bar with a surface profile engineered to grip concrete the way bare steel does. For agencies working toward 100-year service life targets, it addresses the one trade-off that has historically constrained epoxy-coated reinforcement without asking specifiers to give up the corrosion barrier they already trust.
| Specifying corrosion-resistant reinforcement? Learn More about textured epoxy-coated reinforcing steel from the Epoxy Interest Group, or review the ASTM A1124 technology overview. |
Frequently Asked Questions
What is textured epoxy coating for rebar?
Textured epoxy coating is a dual-coat fusion-bonded epoxy system governed by ASTM A1124. A textured second layer is applied over a standard ASTM A775 base coat while the base is still molten, so the two cure together into a single cross-linked coating that improves mechanical interaction with concrete and adds a wear-tolerant outer surface.
How does textured epoxy coating differ from standard epoxy coated rebar?
The corrosion barrier is the same — the base coat meets ASTM A775 in full. The difference is the surface. Smooth coating reduces friction against concrete, which is why codes apply a coating modification factor to development and splice lengths. The textured surface restores that friction, and testing shows bond and lap-splice capacities comparable to uncoated bar.
What ASTM standard governs textured epoxy-coated rebar?
ASTM A1124/A1124M covers textured epoxy-coated steel reinforcing bars, specifying surface preparation, dual-coat application, total coating thickness, texture roughness, bend flexibility, and identification requirements.1
Does textured epoxy coating eliminate the splice length penalty?
The research points that direction: University of Kansas testing measured lap-splice strength averaging about 1.05 times that of uncoated bar. However, the coating modification factors in the governing design codes have not yet been revised for A1124, and efforts to reference the standard in AASHTO LRFD and ACI are ongoing. Specifiers should apply the factors required by the current governing specification and watch for updates.
Can textured epoxy-coated bar be bent after coating?
Yes. ASTM A1124 carries the same flexibility requirements as ASTM A7751, 2, so bars can be fabricated to shape after coating without coating damage, using standard practice for coated bar.
Where has textured epoxy-coated rebar been used?
It is specified by the Illinois DOT for bridge work, was used in Wisconsin DOT’s Interstate 39 split-deck comparison bridge, and was installed in the new Sherwin-Williams headquarters in Cleveland, Ohio — the first commercial building to use the technology.8, 9
References
1. ASTM International. ASTM A1124/A1124M-24, Standard Specification for Textured Epoxy-Coated Steel Reinforcing Bars. West Conshohocken, PA: ASTM International, 2024.
2. ASTM International. ASTM A775/A775M-22, Standard Specification for Epoxy-Coated Steel Reinforcing Bars. West Conshohocken, PA: ASTM International, 2022.
3. ACI Committee 318. Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19), Table 25.4.2.5 (coating factor ψe). Farmington Hills, MI: American Concrete Institute, 2019.
4. Aryal, A. M., K. Truman, D. Darwin, and M. O’Reilly. Bond Strength of Textured Epoxy-Coated Bars. SM Report No. 151, Structural Engineering and Engineering Materials, University of Kansas Center for Research, Lawrence, KS, January 2023. Research sponsored by Sherwin-Williams. https://iri.ku.edu/sites/iri/files/files/pdfs/SM%20Report%20No.%20151.pdf
5. Andrawes, B., E. Pérez-Claros, and Z. Zhang. Bond Characteristics and Experimental Behavior of Textured Epoxy-Coated Rebars Used in Concrete Bridge Decks. Report No. FHWA-ICT-22-001, Illinois Center for Transportation, Urbana, IL, 2022. https://doi.org/10.36501/0197-9191/22-001
6. Ross, B. E., A. Poursaee, S. Sreedhara, and M. Mueller. Textured Epoxy-Coated and Galvanized Reinforcement to Reduce Cracking in Concrete Bridge Decks and Components. WisDOT ID No. 0092-19-01, Glenn Department of Civil Engineering, Clemson University, 2021. https://wisconsindot.gov/documents2/research/final-reports-proj-briefs/WisDOT-WHRP-project-0092-19-01-final-report.pdf
7. Murphy, A. J. Comparison of Flexural Cracking in Reinforced Concrete Beams with Different Rebar Coatings. M.S. thesis, Clemson University, Clemson, SC, 2021.
8. Illinois Department of Transportation. “Setting the Bar for Longer-Lasting Bridges.” IDOT, 2022. https://idot.illinois.gov/news/stronger-bridges.html
9. Rogozinski, J. D., and A. Del Percio. “Raising the Reinforcing Bar: Introducing Textured Epoxy Coating.” ASPIRE, Winter 2024, pp. 38–40.
Note on sources: the University of Kansas bond program (Ref. 4) was sponsored by Sherwin-Williams, and the drop-test damage-tolerance results summarized in Ref. 9 are manufacturer tests that have not been independently published. Both are disclosed here for transparency; the ASTM A944 beam-end, lap-splice, and ASTM D3170 chipping results are drawn from published reports.