Pollution-eating concrete debuts on I-35W

As drivers approach the new bridge span in Minneapolis that was the site of a deadly collapse last year, they will pass a set of curved 30-ft-long concrete strips just as the bridge begins to span the Mississippi River. More than just visual cues to the river passing underneath, the strips are also functionalized. The concrete used to make them is mixed with an Italian compound called TX Active, which is designed to turn pollutants—such as sulfur dioxides and carbon monoxide—into salt. This photocatalytic process occurs on the surface of the concrete, and is activated by ultraviolet light. The company that developed TX Active believes that widespread use of the titanium-dioxide-laced compound in urban environments could cut airborne pollution by as much as half, though the limited application in the St. Anthony Falls Bridge isn't likely to have much of an impact on the surrounding environment. They will stand out, though—the smog-eating material is self-cleaning, and should gleam on even the grimiest, slushiest midwinter Minneapolis morning. This is the first major installation of the compound in the U.S., and the bridge designers hope that this primarily aesthetic element will lead to greater recognition of what could be a revolutionary standard in building materials.

In addition, the bridge makes extensive use of light-emitting diodes. In fact, the entire span is illuminated with LED, marking the longest continuous LED unit in use, stretching 1,300 feet. The fixtures are expected to last about 15 years, reducing maintenance costs.

Finally, the bridge uses self-consolidating concrete, which allowed the project to finish more quickly, and has 323 sensors administered by the Univ. of Minnesota which do everything from monitor structure to deploy anti-icing chemicals at the appropriate time.

Read more here, http://www.popularmechanics.com/technology/transportation/4285220.html?page=1

SOURCE: Popular Mechanics

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