Ultra High Performance Concrete Used as a Coating
Can ultra high performance concrete be used as a coating?
Need and Benefit
Concrete is coated regularly, especially for quick repairs. Sometimes these coatings would need a 50+ year service life to keep up with the surrounding structure. Other times the coating requires specific properties that must match the parent concrete it is on. Currently no modern coatings have been able to achieve these traits.
Ultra high performance concrete (UHPC) may solve this problem. UHPC is not only very high strength, 21.7 ksi minimum, but is also impermeable. Being impermeable puts this concrete in a low to zero risk for any deterioration mechanisms to exist. To name a few: UHPC would prevent freeze/thaw, sulfate attack, alkali silica reaction, corrosion, and possibly hairline cracking. Although considered expensive when compared to typical concrete, UHPC could be significantly cheaper than coating systems.
Specific mix designs allow the material to be applied similar to any other coating but does not contain toxic chemicals or materials. This could be applied just like shotcrete in most instances. Since concrete is the second most used material in the world, most contractors are very familiar with it and would require nearly zero training to use UHPC in a standard concrete or shotcrete application.
The cheaper alternative, durability opportunities, and compatibility to concrete make UHPC a great candidate versus our current coating systems.
Contact the Principal Investigator for information about partners.
Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Ultra High Performance Concrete Used as a Coating (final, PDF, 549KB)
By John (Bret) Robertson
Publication completed on September 30, 2015