Self-cleaning Concrete: Applications

The Photocatalytic Cement is already being used for sound barriers, concrete paver blocks, façade elements. Other applications include:

* Precast and architectural concrete panels
* Pavements, road surfacing and sidewalks
* Portland cement-based plaster for finish coat applications
* Concrete masonry units, roof tiles and cement-based tiles
* Cement-based restoration products

The best applications, for cost effectiveness, include any product used in thin layers or produced in a two-stage manufacturing process (with structural and face mixtures).

In one of the more innovative applications, Italcementi has successfully partnered with lighting system makers to develop artificial lighting systems that generate enough ultraviolet light to activate the photocatalytic process. The lighting system and photocatalytic cement concrete have been used in the renovation of a heavily trafficked tunnel in Rome.

The Photocatalytic cement has already been used in North America. A white precast concrete carillon tower was constructed at Dalton State College in Georgia. The 23 m tall tower is the centerpiece of a new quadrangle project and is visible from a nearby freeway, so it is important that it remains pristine.
Hyacinth Place, an affordable “green” housing complex in Highland Park, IL, has courtyard areas with concrete pavers incorporating photocatalytic cement. The pavers help clean the air as well as store and filter storm water that would have normally been nuisance runoff. The photocatalytic cement was used to
produce two 9 m tall gateway elements at the entrances to the new I-35 W bridge in Minneapolis, MN. These gleaming white concrete sculptures represent the
international symbol for water and serve as markers to remind travelers they’re crossing the Mississippi River. With the help of advanced technology and energy from the sun, they will remain proud symbols for decades to come.

The rain washes away the pollution from the concrete surface, hence buildings stay cleaner and do not require chemical applications that are potentially harmful to the environment. Maintenance costs are reduced. This is true even for buildings in highly polluted locations. One noted application is the Air France headquarters at Roissy-Charles de Gaulle International Airport near Paris, a white concrete building that has remained white. Another is the Church of the Year 2000 in Rome.

Clean buildings are great. Perhaps even more astounding environmental benefit is the potential for cleaner air. Concrete products that are exposed to sunlight throughout their life, like precast building panels, pavers and roof tiles, are especially suited to manufacture with photocatalytic cement. For instance, city streets made with special pavers are capable of reducing the pollution at its source—where it comes out of the tailpipe.

Question:

Discuss techno-economic feasibility of using Photocatalytic Cement in a building project

Reference:

(1) Barbesta M. and Schaffer D, "Concrete that cleans itself and the air", Concrete international, February 2009, pp 49-51