Corrosion of reinforcing steel in concrete is an insidious problem facing KSC, other Government agencies, and the general public. These problems include damage to KSC launch support structures, such as transportation and marine infrastructures, as well as building structures. Because of these problems, the development of a galvanic liquid applied coating (LAC) system would be a breakthrough technology having great commercial value for the following industries: transportation infrastructure, marine infrastructure, civil engineering, and construction. The present effort to develop this type of system is directed at several goals:

• Phase I concentrated on the formulation of coatings with easy application characteristics, predictable galvanic activity, long-term protection, and minimum environmental impact. These new coating features, along with the electrical connection system, will successfully protect the embedded reinforcing steel through the sacrificial cathodic protection action of the coating.
• Phase II improved on the formulations, included optimizing metallic loading, and incorporated a humectant for continuous activation. In addition, development of optimum electrical connections will continue.
• Phase III will incorporate improvements from the previous phases to the test blocks.
• Phase IV will incorporate the final upgrades onto large structures that are heavily instrumented (figure 1).

Figure 1. Phase IV Test Slab

Laboratory testing has demonstrated the commercial potential of this technology. Presently, testing is being conducted at the KSC Materials Science Beach Corrosion Test Site with positive preliminary results (figure 2) demonstrating that the coating meets the National Association of Corrosion Engineers criterion for effective cathodic protection. In addition, the data is being collected and remotely accessed from offsite locations (figure 3).

Successful development and continued optimization of this breakthrough system would produce great interest in NASA/KSC Corrosion Technology Testbed Facilities. Commercial patents on this technology would enhance KSC’s ability to attract industry partners for similar corrosion control applications and establish the Corrosion Technology Testbed as a leader in solving corrosion problems.

Key accomplishments:

• Proved the feasibility of using liquid applied coatings for protection of embedded reinforcing steel in concrete.
• Determined the optimum mix ratio for specific liquid applied coatings.
• Determined that the addition of moisture attractors shows little or no benefit to coating performance.
• Developed improved electrical connectivity between the coating and the internal reinforcing steel.
• Added intensive embedded instrumentation in new simulated concrete structures for monitoring corrosion protection.

Key milestones:

• 2001/2002: Move the liquid applied coatings testing from small-size samples (11 6 4.5 inches) to larger structures (4 feet 4 feet 7 inches). The new structure concrete design mix will include chlorides to simulate a contaminated reinforced concrete structure.

Contacts: L.G. MacDowell (Louis.MacDowell-1@ksc.nasa.gov), YA-C2-T, (321) 867-4550; and Dr. L.M. Calle, YA-C2-T, (321) 867-3278
Participating Organization: Dynacs Inc. (J.J. Curran and J.P. Curran)