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WASHINGTON, D.C.—It’s no secret that many of America’s bridges are in sad shape. One of the reasons is the corrosion of the steel rebar used to strengthen concrete structures. Deluged with de-icing salt and acidic compounds from industrial production, the steel weakens—potentially leading to disasters.

But changing the composition of the concrete can help reinforce the steel, according to Michael Loy, 17, one of 40 finalists in the 2009 Intel Science Talent Search here in Washington, D.C. this week for the final rounds of judging. (Read all of our coverage in this In-Depth Report.)

Loy, a student at Oregon Episcopal School, discovered that adding a certain mix of sodium borate to the concrete kept the steel from corroding under extreme conditions far better than a control mixture—to the point of being “still shiny, like it’s brand new,” he says. The steel also turned out to be 10 to 20 percent stronger in tests. He also had a  unique way of presenting some of the data—as a comic [see photo above].

Loy hit upon the idea for his project while working at a structural engineering company in Portland last summer. The company was retrofitting an old department store to become a hotel. Loy’s boss took him up on the 10th floor, then called him over and showed him one of the steel beams inside the old concrete. The metal was rusted, corroded and “generally not looking too good.” His first thought (after wondering how quickly he could get off the 10th floor) was that “if it’s happening here, it’s probably a problem elsewhere.”

After surveying the field and finding out that it was an extensive problem, he began tests at Portland State University and through a private testing service to determine ways to make the concrete stronger. He tested various solutions before finding out that sodium borate worked best. This is good news, because “it’s much cheaper than anything on the market – before I take my little cut,” he notes. He’s been offered a job at W. R. Grace, a Cambridge, Mass.–based firm that produces building materials, among other things, this summer, to continue his research and potentially bring the technology to market.

Photo of Michael Loy by one of his posters, at a pre-gala reception, by Laura Vanderkam/copyright Scientific American

2 Comments

1. 1. pgtruspace 12:28 AM 3/13/09

   I'm impressed, If this is for real and does not degrade the concrete this young man deserves a Nobel Prize. The corrosion of rebar in concrete and support steel, that is caused by moisture in the concrete is a major destroyer of things of ferro-cement construction. A most valuable contribution to the world.

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2. 2. j.quasimodo 05:27 AM 3/13/09

   The article is rather shallow; it doesn't mention the major mechanism by which corrosion of rebar destroys the integrity of a structure. Since the corrosion product ("rust") occupies a larger volume than the iron it's made from, corrosion results in the concrete spalling off the rebar. That's more significant in weakening the structure than the loss of tensile strength of the the steel. But the idea is still valid if, as pgtruspace suggests, it doesn't degrade the concrete. One more caveat: this is a problem that takes decades to show up. How did a 17-year-old come up with valid data?

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