We've heard of roads being built from pollution-eating concrete before. In Minneapolis, Minnesota, though, it's the roadside sculptures being made from the eco-friendly new concrete from Cemstone. Apparently, the unique mixture used for the wave-like sculptures is photocatalytic, meaning that it uses light to remove carbon monoxide, nitrous oxides and sulfur dioxide from the atmosphere. The outside skin of the sculptures will always be oxidized, which then oxidizes the pollution-causing gases as they come into contact with its white outer layer in much the same way that the catalytic converter in all modern cars works.
The sculptures are designed to look like the international cartographic symbol for water, fitting as the 35W bridge holding them spans the Mississippi River. This bridge was recently rebuilt after it suffered a catastrophic structural failure late last year. LEDs were chosen to provide light to both the scultpures, lit blue at night, and the entire span of the bridge.
/ Photo: David Joles, Star Tribune