Translucent concrete is a concrete based building material with light-transmissive properties due to embedded light optical elements - usually fibers. Light is conducted though the stone from one end to the other. Therefore the fibers have to go through the whole object. This results into a certain light pattern on the other surface, depending on the fiber structure. Shadows cast onto one side appear as silhouettes through the material.

Translucent concrete is used in fine architecture as a façade material and for cladding of interior walls. But light-transmitting concrete has also been applied to a lot of design products.

Fabrication

Several ways of producing translucent concrete do exist. But all are based on a fine grain concrete (ca. 95%) and only 5% light conducting elements that are added during casting process. After setting the concrete is cut to plates or stones with standard machinery for cutting stone materials.

Mounting

Working with natural light it has to be ensured that enough light is available. Wall mounting systems need to be equipped with some form of lighting and designed to achieve uniform illumination on the full plate surface.
Usually mounting systems similar to natural stone panels are used - e.g. LUCEM uses perforated mounting with visible screws, undercut anchors with agraffes or façade anchors.

History

Translucent concrete has been first mentioned in a 1935 Canadian patent. But since the development of optical glass fibers and polymer based optical fibers the rate of inventions and developments in this field has drastically increased. There have also been inventions that apply this concept to more technical applications like fissure detection. In the early 1990s forms like translucent concrete products popular today with fine & layered patterns were developed.

Today several companies produce translucent concrete with very different production systems.
Some manufacturers are:

• Florak Bauunternehmung GmbH, Heinsberg/Germany
• LBM EFO, Berching/Germany
• Litracon Bft, Czongrad/Hungary
• LUCEM GmbH, Stolberg/Germany
• Luccon Lichtbeton GmbH, Klaus/Austria

Variants

Appart from fine fiber patterns due to the use of optical fibers or textiles some products with much coarser light pattern are available. The main advantage of these products is that on large scale objects the texture is still visible - while the texture of finer translucent concrete becomes indistinct at distance. Further pictorgrams and lettering can be realized with this technology.