A look at the lighter side of concrete
Although it’s been in existence for some years, there’s an eye-catching phenomenon that’s capturing the imaginations of more and more architects, designers and building owners worldwide as word spreads and new developments are made. Translucent or light-transmitting concrete is going up in availability, down in price and getting ever more versatile.
Some will be familiar with the sight of walls clad in translucent concrete, but German-based manufacturer, LUCEM, has now taken things to a new level. Floor level in fact, because LUCEM’s latest installation - which has just been completed in the lobby of investment advisor, London & Oriental’s London offices - features flooring for the first time.
According to a LUCEM announcement about the project, the new flooring produces a rather special effect. Its press release states: “Without light, the LUCEM floor panels appear as elegant natural stone panels, but illuminated, the panels seem to glow and due to the conical shaped light effect of each fibre, the light seems to be brighter the more the viewer is above the single panel. It seems as if there is a spotlight following the viewer.”
In comparison to the wall cladding, the floor application required greater load bearing capacity from each panel. They were therefore manufactured at 30-40mm thickness and in a maximum format of 60 x 60cm. LUCEM wall panels can be used in 20-30mm thickness and in sizes of up to 150 x 60cm.
So how is concrete made translucent to begin with? Using thousands of optical fibres embedded into the concrete, daylight or artificial light can travel through the concrete panels - no matter how thick they are. In the past, translucent concrete was made manually, which meant only limited amounts could be produced and it was very expensive.
However in 2011, LUCEM developed a patented production process, increasing production and lowering prices significantly. Several other European companies - including Florak Bauunternehmung, LBM EFO, liTraCon, Luccon, and LiCrete - have also developed their own production processes, all of which vary.
Light transmitting concrete can be used to create various effects, for example a starry sky (like a star-cloth but concrete), panels where the optic fibres are laid into the concrete in such a way they depict a logo when lit, or for creating silhouette forms. Panels also come in different textures, colours and finishes.
As mentioned, there’s more than one way to manufacture translucent concrete, but essentially they’re all based on a fine grain concrete (ca. 95%) and 5% light conducting elements that are added during the casting process. After setting, the concrete is cut into slabs using standard stone cutting machinery.
It’s possible to fit individual panels with their own light source allowing over 16 million colours each. This allows designers to programme the light sources to create gently changing colour displays as each panel graduates through the spectrum. Bars, restaurants, nightclubs and galleries would be obvious settings for this type of effect.
Using translucent concrete for floors does raise the question of how to keep the panels clean. Do the optic fibres eventually dim under a layer of grime? In the case of LUCEM, the panels are impregnated with a hydrophobic substance that repels water and dirt. This can be refreshed periodically when the coating starts to wear off. More detailed care guides are available but, as a rule of thumb, abrasives and acids are bad, humble glass or ceramic cleaner is good.
It will be interesting to see what future holds for translucent concrete as the technology continues to develop and new innovations and architectural applications emerge.