The current impetus toward “greener” energy has resulted in the proliferation of hundreds of thousands of wind turbines around the world. These find themselves in every place from wide open farmland in the Midwestern United States to offshore wind farms based in saltwater oceans. As the wind industry matures, it is evident that sustainability must be considered in another respect beyond the renewability of energy. Extending the service life of these high-investment assets that produce the energy is also important, because they themselves consume scarce resources. One great strategy for helping wind towers last longer is to mitigate corrosion in reinforced concrete components using Cortec® Migrating Corrosion Inhibitors (MCI®).
Taking Concrete From Grey to Green™
MCI® Technology extends concrete service life by mitigating corrosion on embedded reinforcing metal. Corrosion is one of the chief enemies of concrete longevity because it leads to cracking, spalling, and eventual deterioration of the structure. Since concrete production is such an energy intensive activity, helping concrete last longer is an important part of a sustainability-savvy and resource-efficient society. The less often that concrete repairs or replacements have to be made, the more resources are saved, and the smaller the concrete carbon footprint becomes.
Vulnerable Wind Turbine Structures
Many wind turbines are situated in corrosive environments, although some regions pose greater risk for corrosion than others. For example, land-based wind turbines in coastal and/or tropical environments may encounter a high degree of airborne chlorides from coastal wind and sea spray (exacerbated by high temperatures) that can lead to early corrosion in reinforced concrete wind turbine foundations. Some offshore wind turbines are constructed on concrete gravity bases that are towed out to sea and filled with seawater to weight them down on the ocean floor. These high-chloride environments can have a potentially serious corrosive effect on subsea concrete structures over time, especially if cracking occurs and gives the chlorides direct access to the reinforcing steel. However, MCI® Technology can be of great benefit to counteract the progress of corrosion through proper use during construction and concrete repairs.
When to Use MCI®
The best time to apply Migrating Corrosion Inhibitors is when pouring new cast-in-place structures or precast concrete elements (e.g., concrete gravity bases). MCI® admixtures introduce amine carboxylates to the concrete mix without negatively impacting physical properties. MCI® molecules form a protective layer on the surface of the reinforcing metal that delays time to corrosion and reduces corrosion rates once started. Existing structures can benefit from corrosion protection as well. A rust-converting/passivating metal primer is an excellent option for prepping exposed rusted rebar during concrete repairs. MCI® surface applied corrosion inhibitors (SACI) with or without water repellents are excellent additions to enhance the lifetime of the repair or to apply simply for periodic maintenance on concrete wind turbine bases. These SACIs migrate through the concrete pores to reach and protect embedded reinforcement. In underwater environments, these SACIs should be topped with a waterproofing membrane. For surfaces in need of repair where oil stains are present, a biological-based cleaner that uses biodegradable surfactants and microorganisms to remove oil stains is an excellent choice before the application of a SACI, a coating, or a membrane system.
Take Responsibility for Critical Resource Stewardship
The wind turbine industry is a fast-growing sector of today’s energy infrastructure that demands responsible stewardship. By taking basic steps like using MCI® Technology to extend service life—particularly for at-risk structures in corrosive environments—the wind energy industry can save time and money while indirectly reducing their carbon footprint. Contact Cortec® for further assistance in finding ways to enhance the sustainability of concrete wind turbine components: https://www.cortecmci.com/contact-us/
Special thanks to Ash Hasania (MCI® Technical Sales & Market Manager) and Lisa Marston (Technical Service Engineer) for their support as MCI® subject matter experts.
Exposed metal reinforcement of wind tower base awaiting a concrete pour. Adobe Stock image courtesy of Cortec®.
Julie Holmquist is the Marketing Content Writer at Cortec Corporation. She has served in this role for close to seven years and has written on a variety of corrosion related topics from concrete longevity to electronics protection. Email: email@example.com.