Another take on light-transmitting concrete

17 Dec 2007

A new "translucent concrete" is said to offer users greater design flexibility.

When optics.org wrote about a new light-transmitting concrete called LitraCon three years ago, we had no idea that the story would garner such sustained interest among our readers (see Concrete casts light in dull rooms). So when we discovered that Andreas Bittis – a former colleague of LitraCon inventor Áron Losonczi – had introduced a new "translucent concrete", we had to find out more.

"The original LitraCon embedded single optical fibers within the concrete, which limited the size of the blocks to 60 cm x 90 cm," Bittis told optics.org. "Our approach uses a number of optical fibers formed into a textile, which allows us to increase the block size up to 2.0 m x 1.2 m."

Like the original LitraCon, the new translucent concrete embeds optical fibers into a concrete matrix, which effectively offers a view of the outside world through a solid wall. But the textile approach also offers the potential for producing curved structures as well as rectangular blocks, a possibility that Bittis plans to investigate further in 2009.

"Thousands of fibers run side by side to transmit light between the two surfaces of each element," explained Bittis. "Shadows on the lighter side appear with sharp outlines on the darker one, and even the colors remain the same."

Bittis maintains that incorporating optical fibers into the concrete has no affect on the material's strength. "Because of their small size the fibers blend into the concrete, becoming a component of the material like small pieces of ballast," he explained. "Since the amount of optical fiber is only 5%, translucent concrete blocks have the same technical data as the concrete used for them."

As a result, the translucent concrete blocks can be used for load-bearing structures. A wall made with the blocks can also be several metres thick, since the fibers lose almost no light for distances of up to 20 m.

The original LitraCon product was invented and patented by Losonczi, an architect from Csongrád in Hungary, back in 2002. It is still available through Losonczi's company, which is also called LitraCon.

Meanwhile, Bittis' translucent concrete blocks are already on sale. "The blocks are produced depending on the aesthetical and structural needs of the project," he said. "All sizes of precast concrete are possible: from small bricks to façade plates and passable paving stones, all illuminated from beneath."