98 The Masterbuilder - September 2013 • www.masterbuilder.co.in

Light Transmitting Concrete Panels – A New Innovation in Concrete Technology

Transparent concrete is a concrete based building material with light-Tran missive properties due to embedded light optical elements usually Optical

fibres. Light is conducted through the stone from one end to the other. Therefore the fibres have to go through the whole object. Transparent concrete is also known as the translucent concrete and light transmitting concrete because of its properties. It is used in fine architecture as a facade material and for cladding of interior walls. The main purpose is to use sunlight as a light source to reduce the power consumption of illumination and to use the optical fiber to sense the stress of structures and also use this concrete as an architectural purpose for good aesthetical view of the building. Refer Figure 1 for Transparent Concrete Panels.

MB Bureau

Background

In 2001, the concept of transparent concrete was first put forward by Hungarian architect AronLosonzi, and the first transparent concrete block was successfully produced by mixing large amount of glass fiber into concrete in 2003, named as LiTraCon. Joel S. and Sergio O.G. developed a transparent concrete material, which can allow 80% light through and only 30% of weight of common concrete. It is worth mentioning that Italian Pavilion in Shanghai Expo 2010 shows a kind of transparent concrete developed by mixing glass into concrete in 2010. While the transparent concrete mainly focuses on transparency and its objective of application pertains to green technology and artistic finish.

Transparent Concrete

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Functional principle

Diffuse natural light and sun light provide the full spectrum of colors shining through the concrete panels. Sunlight is the most inexpensive light source. If the panel is mounted free standing or in front of a window, one will not need any artificial light source. Transparent concrete or translucent concrete is work Based on “Nano-Optics”. Optical fibres passes as much light when tiny slits are placed directly on top of each other as when they are staggered. Principal can carry because optical fibers in the concrete act like the slits and carry the light across throughout the concrete.

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Figure 1: (a) Exterior view Jarbeurslaan, Genk, (b) Light shining through at the hallway, (c) Shadows shining through the wall. (www.lucem.de)

light-electrical or photochemical process, and photo elastic effect which can be used to study the stress distribution of structures. Combining the advantages of the concrete and optical fiber, developing a novel functional material called transparent concrete has an important value in the application of construction and sensing.

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Material Used for Transparent Concrete

There are two basic materials used for making transparent concrete, one is from construction field and another from sensing field. First, concrete is one of the most important civil engineering materials with the advantages of rich raw materials, low cost and simple production process and second the optical fiber has good light guiding property which can be arrange to transmit the light and the sun light transmit according to pre-design road without light-heat,

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Figure 1: Transparent Concrete Panels (Source: entertainingscience.blogspot.com)

Transparent Concrete

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Manufacturing Process

The manufacturing process of transparent concrete is almost same as regular concrete. Only optical fibres are spread throughout the aggregate and cement mix. Small layers of the concrete are poured on top of each other and infused with the fibers and are then connected. Thousands of strands of optical fibers are cast into concrete to transmit light, either natural or artificial.Light-transmitting concrete is produced by adding 4% to 5% optical fibers by volume into the concrete mixture. The concrete mixture is made from fine materials only it does not contain coarse aggregate. Thickness of the optical fibers can be varied between 2 μm and 2 mm to suit the particular requirements of light transmission.

Role of Lucem Lichtbeton in this Innovations: German concrete manufacturer Lucem lichtbeton, is one of the leading

companies involved in this production of light transmitting concrete. As part of the project, which was designed by Aachen-based architects Carpus & Partner, 150cm by 50cm concrete panels containing optical fibres have been used, forming a total area 30m wide by 4m high with 136 panels. Each panel is fitting with colour-changing technology, with the colours becoming brighter approximately one hour before sunset. The LED-panels are controlled using an internet-based DMX technology system, with each panel containing 3% optical fibres. The technology controlling the lights opens up new boundaries for design and architecture as the light panels are made with red, green and blue chips which control more than 16 million colours. As well as this, all the panels can be controlled independently meaning the entire facade can become a large display screen. The light shows on the screen can be controlled via the internet or a mobile device and interactive elements as well as text and logos can be displayed on the screen. According to Lucem, the panels have various uses including ‘facades, interior walls, claddings and flooring systems up to the design of room dividers and bars’. There are currently three different types of Lucem® Lichbeton panels, which offer different effects and aesthetics for the user. With the Lucem® Label panels, light transmitting fibres are arranged individually so that clients can display design logos, images, names, signatures and icons on the panels.

Some application areas of Lucem are as mentioned below:-

A. Clinic Genk - Surgical Clinic, Partition Wall

Classiness, high-grade furnishing and flawless services for public health. The new building of an oral surgery clinig presents a large-sized Lucem wall used as a room divider. A brightly illuminated waiting area induces an interesting shadow play on the part of the offices. Throughout the

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Figure 2: (a) Day View, (b) Close up – Edge, (c) Mark - passage to the Park. (www.lucem.de)

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Figure 3: (a) Light panel elevator, (b) Entrance. (www.lucem.de)

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massive wall the amount of waiting patients can be counted. The room concept in the whole clinic, being divided into waiting area, consultation area and medical treatment area, was designed as massive wall construction consisting out of Lucem Lichtbeton and being translucent and brightly lighted in the outer appearance. Refer Figure 1 (a), (b) and (c).

B. Nesselande, Rotterdam, Outside illumination - promenade at Oeverpark

In Rotterdams district Nesselande a local recreation area was created. Long bands of concrete were integrated into the landscape enclosing the greenery on the one side and being a bench on the other side. Near the port of Rotterdam in a public park right at the waterfront - perfect conditions to install Lucem as a outdoor application to prove the quality of Lucem light transmitting concrete. Refer Figure 2(a), (b), (c).

C. Signal Iduna, Extension of the main administration building of Signal Iduna insurances, Dortmund

Roomconcept, color design, materiality and art: those were the main subjects, Sassan Philip Haschemi & Associates worked on, picking Lucem Line panels as a special highlight: Lucem light transmitting concrete panels for the entrance hall and the excecutive suite. The Lucem Line panels have been designed as floor to ceiling wall claddings utilising free space behind the panels for light supply. The special color of the light source was made consistent with the colors of the interior design by using a LED source with warm-white light.

D. Residential house in Luxemburg

appeared. A novel architectural material called transparent concrete can be developed by adding optical fibre or large diameter glass fibre in the concrete mixture. The transparent concrete has good light guiding property and the ratio of optical fibre volume to concrete is proportion to transmission. The transparent concrete not looses the strength parameter when compared to regular concrete and also it has very vital property for the aesthetical point of view. It can be used for the best architectural appearance of the building. Also used where the light cannot reach with appropriate intensity. This new kind of building material can integrate the concept of green energy saving with the usage self-sensing properties of functional materials.

Reference

- Kalymnios, D. Plastic Optical Fibers (POF) in sensing – current status and prospects. 17th International Conference on Optical Fiber Sensors SPIE, 5855, 2005.

- Scherafe, T. “fabric Structure outpace applications: Recent structural development expand the range of fabric options”, Building design and construction, pp.128-138,1988.

- F. Ansari. Practical Implementation of Optical Fiber Sensors in Civil Structural Health Monitoring. Journal of Intelligent Material Systems and Structures, 18(8):879-889, 2007.

- Jianping He, Zhi Zhou, JinpingOu, Minghua Huang, “Study on Smart Transparent Concrete Product and Its Performances”, Dalian, China, 2011.

- D.D.L. Chung. Cement reinforced with short carbon fibers: a multifunctional material. Composites: Part B.31:511-526, 2000.

- K.S.C. Kuang, M. Maalej, S.T. Quek. Hybrid optical fiber sensor system based on fiber Bragg gratings and plastic optical fibers for health monitoring of engineering structures. Proc. of SPIE, 6174(61742P) 1-12, 2006.

- H.Li, H.G. Xiao, J.P. Ou. Microstructure of cement mortar with nano-particles. Composites Part B Engineering, 35:185-189, 2004.

- Victoria Bailey, “Translucent Concrete”, MEEN 3344-001

- Z. Zhou, J.P. Ou, and B. Wang. Smart FRP-OFGB Bars and Their Application in Reinforced Concrete Beams. Proceedings of the First International Conference on Structural Health Monitoring and Intelligent Structure, Japan: 861~866, 2003.

- seminarprojects.com/s/transparent-concrete-ppt

- www.impactlightinginc.com

- www.litracon.hu/

- http://www.magtudin.org/Translucent%20concrete.htm

- http://www.nbmcw.com/articles/concrete/17991-transparent-concrete-litracon.html

- www.thesurfacegallery.com/product/litracon/

- www.lucem.de

- A Study on Transparent Concrete: A Novel Architectural Material to Explore Construction Sector, Bhavin K. Kashiyani, Varsha Raina, Jayeshkumar Pitroda, Dr. Bhavnaben K. Shah, International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 8, February 2013.

Figure 4: (a), (b) A Light Transmitting Wall Panel. (www.lucem.de)

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Conclusion

Concrete is no longer the heavy, cold and grey material of the past; it has become beautiful and lively. By research and innovation, newly developed concrete has been created which is more resistant, lighter, white or colored, etc. Concrete has learned to adapt to almost all new challenges that

Transparent Concrete