Researchers at Missouri University of Science and Technology have developed a glass-based coating for reinforcement bars that helps prevent corrosion and strengthens the bond between steel and concrete. This material could help engineers build stronger bridges and increase the longevity of other steel-reinforced structures.
Currently, the U.S. market for polymer-coated and galvanized rebar in the construction industry is more than $4 billion per year. But research has shown that polymer coatings are not providing adequate corrosion protection for the rebar that helps to reinforce the nation’s aging infrastructure.
The Missouri S&T coating is an engineered mixture of glass, clays and water. A slurry is applied to the rebar and heated to more than 1,400 degrees Fahrenheit. The coating, which adheres to steel, promotes bonding with concrete and works to prevent corrosion from water and salt.
Missouri S&T has filed for a patent on the technology, which was developed by a team of researchers led by Dr. Richard Brow, Curators’ Professor of materials science and engineering, and Dr. Genda Chen, professor of civil, architectural and environmental engineering and interim director of the Center for Infrastructure Engineering Studies at S&T. The research was funded by the Leonard Wood Institute.
The Department of Defense has used related technology to develop blast-resistant walls. Brow and Chen realized that some ideas originally conceived by the U.S. Army Corps of Engineers could be built upon in order to engineer the glass-ceramic coating for rebar.
Missouri S&T recently licensed the new technology to Pro-Perma Engineered Coatings in St. Louis. “The goal is to take innovations like this out of the laboratory, team up with partners, solve problems, and make an economic impact,” says Keith Strassner, director of technology transfer and economic development at Missouri S&T.
Mike Koenigstein, who earned a bachelor’s degree in ceramic engineering at Missouri S&T in 1993, is managing partner of Pro-Perma. So far, he says, the company has two projects in the works that utilize the new coating. The first will involve the strengthening of marine structures in Corpus Christi, Texas. Next, Koenigstein plans to strengthen a sea wall near Pearl Harbor in Oahu. Both projects are sponsored by the Department of Defense.
In addition to protecting structures from water and salt, Brow and Chen say the new coating would help make bridges and buildings stronger in earthquake-prone regions.
According to Chen, there are approximately 800 short-span bridges in Missouri that need to be retrofitted or replaced. In addition, more than 200 longer-span bridges are in urgent need of rehabilitation.
Strassner and Koenigstein think the new rebar coating will prove to be in high demand. They envision opening a pilot plant dedicated to producing the glass-based coating in Rolla, which is already home to high-tech glass manufacturer Mo-Sci Corp. as well as Missouri S&T.
Pro-Perma and Mo-Sci are working as partners to commercialize the technology developed at Missouri S&T.
“We have all of the resources here to support technology-driven businesses,” Strassner says. “We want to be an economic engine for the state of Missouri.”