Smog-Eating Concrete Is the New Highway 141
Really? What is it?
A revolutionary type of concrete that absorbs smog and uses sunlight to break it down into nitrogen and carbon dioxide for release into the air is paving the new Highway 141 near Town and Country.
The Missouri Department of Transportation (MoDOT) believes this is being tested in the U.S. for the first time.
Apparently a "photo-catalytic additive of titanium dioxide" in the concrete has already been used in Europe for its smog-busting abilities, MoDOT said.
Photo-catalytic typically means light-activated.
MoDOT and contractor Fred Weber Inc., were scheduled to place the first slab of new concrete Monday morning on a section of Hwy. 141 between Ladue and Olive roads.
Here's how MoDOT described the process in a written statement:
Workers will use a process called two-lift paving to place this section of concrete.
In this process, crews lay down a thick layer of concrete and then immediately place a second, thinner “lift” or layer of concrete on top of that thick layer.
Concrete placed using this method is as strong as that used on standard concrete pours.
This process lets the department place two different concrete mixtures. Since the titanium dioxide additive is expensive, this paving technique lets the department use the additive in the thinner top lift while still getting the benefit of a thick slab of concrete.
MoDOT will test a 1,500 foot section of the new Route 141 with this smog-eating concrete. The test period for the concrete will start when Route 141 opens up to traffic in mid-2012.