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27 May 2009

New coating reduces corrosion, strengthens steel

A new glass-based coating for reinforcement bars could help prevent corrosion and strengthen the bond between steel and concrete.

This new material could help engineers build stronger bridges and increase the longevity of other steel-reinforced structures, said researchers at Missouri University of Science and Technology.

The market in the U.S. for polymer-coated and galvanized rebar in the construction industry is more than $4 billion per year. But research found polymer coatings are not providing adequate corrosion protection for the rebar that helps to reinforce the nation’s aging infrastructure.

The new coating is an engineered mixture of glass, clays, and water. This slurry slathers on the rebar and then heats to more than 1,400°F. The coating, which adheres to steel, promotes bonding with concrete and works to prevent corrosion from water and salt.

Missouri University of Science and Technology (S&T) has filed for a patent on the technology, 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 U.S. Department of Defense has used related technology to develop blast-resistant walls. Brow and Chen realized they could improve upon some of the ideas originally conceived by the U.S. Army Corps of Engineers.

“The goal is to take innovations like this out of the laboratory, team up with partners, solve problems, and make an economic impact,” said Keith Strassner, director of technology transfer and economic development at Missouri S&T. Missouri S&T licensed the new technology to Pro-Perma Engineered Coatings in St. Louis.

Pro-Perma has two projects in the works that utilize the new coating, said Mike Koenigstein, who earned a bachelor’s degree in ceramic engineering at Missouri S&T in 1993, and is managing partner of Pro-Perma. The first will involve the strengthening of marine structures in Corpus Christi, Tex. Koenigstein also has plans to strengthen a sea wall near Pearl Harbor in Oahu, Hawaii. The Department of Defense is sponsoring the two projects.

In addition to protecting structures from water and salt, Brow and Chen said the new coating would help make bridges and buildings stronger in earthquake-prone regions.

There are 800 short-span bridges in Missouri that need retrofitting or replacement, Chen said. In addition, more than 200 longer-span bridges are in urgent need of rehabilitation.

Strassner and Koenigstein 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.

For related information, go to www.isa.org/manufacturing_automation.