Self-cleaning concrete – or photocatalytic concrete – may sound futuristic, but it’s already being used in parts of Japan and Europe, and has even been used to construct a bridge in Minneapolis, MN.
Self-cleaning concrete works by adding a catalyst, usually titanium dioxide, to the fresh concrete mix. Titanium dioxide activates in the hardened concrete when exposed to the sun. The activation changes titanium dioxide’s electric charge, causing a repelling effect between the concrete and the dirt and pollutants on the concrete surface.
The Jubilee Church in Rome was constructed using self-cleaning concrete.
The next rainfall washes the loosened dirt particles off the concrete surface, keeping the structure looking clean. Photocatalytic materials used in concrete also show promise in helping decompose airborne pollutants like exhaust in congested cities.
While some pollutants that wash off the structure can end up in surrounding soil and groundwater, proponents for the technology say the impact is minimal and is outweighed by the self-cleaning benefit.
Courtesy of ESSROC Italcementi Group.
Schematic showing how titanium dioxide and sunlight work to remove surface contaminants from concrete.
So far, trials have shown titanium dioxide has little effect on fresh or hardened concrete properties. Could this be something new to consider for your next wall panel or architectural project?
More information on self-cleaning concrete can be found here:
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