By Anđela Bogdan, MSc.CE (EYE-HR)
In 2001 Áron Losonczi – back then a 24 year old student – had the striking idea to make concrete blocks look a bit nicer and visually appealing by mixing concrete with optical glass fibers, and the result was Light Transmitting Concrete. In the following two years he had developed a manufacturing technology supported by engineers from the Budapest University of Technology to transform his prototype into a marketable product that can be produced in bigger quantities. In 2003 his invention – LiTraCon– was presented at several exhibitions and given the huge public interest it was obvious that Áron’s solution will be sought after. Driven by the excellent feedback from industry experts he has patented the product and in 2004 founded his company in Csongrád, Hungary to manufacture and market LiTraCon solutions and products worldwide.
Translucent concrete (also: LiTraCon = light-transmitting concrete) is a conrete based building material with light-transmissive properties due to embedded light optical elements —
usually optical fibers. Light is conducted through the stone from one end to the other. Therefore, the fibers have to go through the whole object. This results in 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 facade material and for cladding of interior walls. Light-transmitting concrete has also been applied to various design products.
Several ways of producing translucent concrete exist. All are based on a fine grain concrete (ca. 96%) and only 4% light conducting elements (optical fibers) that are added during casting process. After setting, the concrete is cut to plates or stones with standard machinery for cutting stone materials.
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.
By day, the concrete facade of APG Architecture and Planing Group’s latest project, the Al Aziz Mosque in Abu Dhabi features protruding elements of Arabic script spelling words from the Quran. By night though, the 515 square meterfacade is transformed, as the concrete script lights up in the darkness. The effect is made possible thanks to the translucent concrete paneling system. The translucent concrete used in the facade system works thanks to fiber optics, included as part of the aggregate within the concrete. In this project, LUCEM were able to position these fibers in
accordance with drawings created by the architects and an expert calligrapher. In order to blend with the stone panels used elsewhere on the building’s facade, the concrete used was pigmented to match the stone’s color, and the
panels were sandblasted to give them the correct texture. Though it appears that the facade is lit by light from inside the building, the effect is in fact achieved through a system of LEDs installed within the wall cavity. This required experts to develop a specialized cable system which would allow faulty LEDs to be replaced without removing any of the panels – each of which weighs over 300 kilograms.
The main disadvantage of this interesting material is the price – it’s almost 1300 EUROS per one concrete panel.
The article can also be found in Croatian language. See: www.casopis-gradjevinar.hr/assets/Uploads/JCE-69-2017-4-8-Zanimljivosti.pdf
With picture courtesy to: https://www.lucem.com/
About the author
Anđela Bogdan is Master in Civil Engineering, graduated at the Faculty of Civil Engineering at the University in Zagreb, Croatia. Since 2014, she is an Associate expert at the Croatian Association of Civil Engineers, where she works on the EU project: Continuous Professional Development for Green Building. She is Editor of the scientific/professional journal Gradjevinar. She wrote more than 30 articles about significant and large-scale construction sites and reconstruction/renewal activities. In January 2018, Anđela became a member of EYE Croatia.