I-35 Bridge in Minneapolis Made of Cemstone

 - Oct 13, 2008
References: dwell
A new $234 million bridge in Minneapolis has opened at the site where an old one collapsed, killing 13 in August of 2007. The new Interstate 35W bridge, which crosses over the Mississippi River, integrates two striking, 30-foot tall sculptures representing the international symbol for water.

However, these pillars are not only stunning architectural elements, apparently they are also giant air cleaning devices. "The two sculptures are constructed from a unique concrete that uses ultraviolet sunlight to promote and accelerate oxidation at the surface of the structures. In addition to keeping the sculptures a bright white color, the concrete allows for the conversion of smog-causing gases such as carbon monoxide, nitrous oxides and sulfur dioxide to higher oxidized states. This is the same process used by a catalytic converter in automobiles," according to an article from KSTP.com.

Cemstone, the concrete supplier for the new bridge, is the first company in the U.S. to use this new air cleaning material.

The ecstatic Americans in this video were of the first to cross the newly opened span at 5 in the morning. I found their clip surprisingly emotional.