The cement is called TX Active and the magic ingredient is titanium oxide. When exposed to sunlight, titanium oxide can neutralize some pollutants – basically the toxins are oxidized when they come into contact with the cement. For instance, nitrogen oxide and sulfur oxide gasses are made harmless when they are turned into nitrates or sulfates. Without the catalyst of titanium oxide, the nitrogen and sulfur oxide break down in the atmosphere creating smog and ground level ozone.
From a design perspective, anything that can be made out of concrete is a potential application. Beyond the ubiquitous sidewalks and roads, we could think about using this material in green architecture. Apparently precast building panels or roof tiles are especially suited for such a material. Perhaps most inspired is where the cement meets the source of pollution: Think tunnels and car garages. According to the Environmental Protection Agency stats that 34% of nitrate oxides comes from vehicles on the road.
Last Fall as a pilot project, a two-mile stretch of sidewalk in Chicago was paved with this same cement.