What is Photocatalytic Self-Cleaning Concrete?Self cleaning concrete is produced by adding catalytic material to the concrete mixture. It is a new construction material that has been developed in the past three decades. The most prominent properties of the type of concrete is self cleaning ability. Not only does it preserve façade appearances of structure but also it decomposes most of gases that emits from car exhaust and those produced because of emitted gases with rainwater. The self-cleaning property is obtained by adding an additive to concrete which is called catalytic material which has a white color. An example of catalytic material is the titanium oxide as shown in Figure-1.
Fig.1: Titanium DioxideSelf-cleaning begins when this material is activated, and catalytic material activation will start due to energy that is received from sunlight (it also can be activated using artificial lights). When titanium oxide activates, a charge of separation electrons will be generated which will spread over photocatalytic concrete surface and decompose organic compounds on the concrete surface.
Properties of Photocatalytic Self-Cleaning ConcreteThe properties of concrete both at plastic and hardened stage would not decline by adding photocatalytic materials. Slump, air content, unit weight, set-time, workability, permeability, flexural strength, and compressive are like ordinary concrete provided that proper guidelines are employed.
Advantages of Photocatalytic Self-Cleaning ConcreteThe most outstanding properties of this type of concrete is self cleaning. This lead to maintain aesthetical appearance of structures for a long time. Photocatalytic materials used in the production of photocatalytic concrete will help in decomposition of harmful gases such ozone, and other detrimental gases that produced because of emission gasses with rain water. This is specifically significant in great and congested cities. So, it will decline environmental pollution greatly and save lives of many generations to come. Photocatalytic self-cleaning concrete reflect majority of heat coming from the sun. Consequently, it helps the surface of the structure to retain its low temperature during summer season. It reduces air temperature in urban environment and eventually reduces quantity of smoke.
Fig.2: Photocatalytic materials reduce pollution
- It may not be suitable for interior applications since it needs light to be activated. However, artificial light may decline this disadvantage to a certain extent.
- Photocatalytic self cleaning concrete cannot be labeled graffiti proof since various paints are ultraviolet resistant and become a barrier between sunlight and concrete surface.
Application of Photocatalytic Self-Cleaning ConcreteThere are several applications of photocatalytic concrete which include:
- It is used in the construction of various structures
- It is used in the construction of roads. This is greatly helpful since it decompose some of the gasses while they are emitted from car exhausts.
- It is used in the construction of bridge structure and maintains its visually pleasant appearances.
- Photocatalytic cement can be used to produce mortar, pavement plasters, and precast elements.
- Concrete sidewalks
- Tilt-up concrete panels
- Noise barriers for roads and highways
Examples of using photocatalytic self-cleaning concrete in the world
Fig.3: New jubilee church structure in Rome which is anticipated to remain clean and keep its aesthetical appearance for many years to come
Fig.4: Photocatalytic are used in Japan to keep paving, clean and to reduce the effect of air pollution
Fig.5: Air France company head office structure in France, photocatalytic concrete used in the construction
Fig.6: The Milan Expo