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Int. J. Struct. & Civil Engg. Res. 2013 Akshaya B Kamdi, 2013

TRANSPARENT CONCRETE AS A GREENMATERIAL FOR BUILDING

Akshaya B Kamdi1*

Concrete, that traditionally solid, substantial building material, is getting a makeover. Engineershave now developed concrete mixtures that are capable of transmitting light. By switching theingredients of traditional concrete with transparent ones, or embedding fiber optics, translucentconcrete has become a reality. Light Transmitting concrete, also knows as translucent concrete.It is the brightest building material development in recent years. It is one of the newest, mostfunctional and revolutionary element in green construction material. In this paper the manufacturing,uses and future scope of transparent concrete is widely given. However, this innovative newmaterial, while still partially in the development stages, is beginning to be used in a variety ofapplications in architecture, and promises vast opportunities in the future.

Keywords: Transparent concrete, Optical fibre, Concrete, Aggregate

1 KDKCE, RTM, Nagpur University, Maharashtra, India.

*Corresponding Author: Akshaya B Kamdi,akshaya.kamdi@gmail.com

ISSN 2319 – 6009 www.ijscer.comVol. 2, No. 3, August 2013

© 2013 IJSCER. All Rights Reserved

Int. J. Struct. & Civil Engg. Res. 2013

Research Paper

INTRODUCTIONConcrete has been used since Roman times,but its basic components have remained thesame. Three ingredients make up the dry mix:coarse aggregate, consisting of larger piecesof material l ike stones or gravel; fineaggregate, made up of smaller particles suchas sand; and cement, a very fine powdermaterial that binds the mix together when wateris added. Engineers have come up withseveral potential types of mixtures fortranslucent concrete. One approach is toexchange the traditional ingredients withtransparent or translucent alternatives.Aggregates can be replaced with transparent

alternatives, and the bonding material itselfmay be able to transmit light by incorporatingclear resins in the mix. Another approach isthe “combination of optical fibers and fineconcrete”.

MATERIAL USED FORMANUFACTURING OFTRANSPARENT CONCRETEIt is a combination of fibre optics and fineconcrete. It can be produced as prefabricatedbuilding blocks and panels. Due to the smallsize of the fibers, they blend into concretebecoming a component of the material likesmall pieces of aggregate.

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Thousands of optical fibers strands areplaced in concrete to transmit light, eithernatural or artificial, into all spaces enclosedby the translucent concrete panels.

between two surfaces of the concreteelement in which they are embedded.Thickness of the optical fibers can be variedbetween 2 µm and 2 mm to suit theparticular requirements of l ighttransmission.

2. Originally, the fiber filaments were placedindividually in the concrete, makingproduction time-consuming and costly.Newer, semi-automatic production processesuse woven fiber fabric instead of singlefi laments. Fabric and concrete arealternately inserted into molds at intervalsof approximately 2 mm to 5 mm. Smaller orthinner layers allow an increased amount oflight to pass through the concrete. Followingcasting, the material is cut into panels orblocks of the specified thickness and thesurface is then typically polished, resultingin finishes ranging from semi-gloss to high-gloss.

3. The concrete mixture is made from finematerials only: it contains no coarseaggregate. The compressive strength ofgreater than 70 MPa (over 10,000 psi) iscomparable to that of high-strengthconcretes.

USED OF TRANSLUCENTCONCRETETranslucent concrete is not currently widelyproduced. There are only a select fewcompanies, and the process is somewhat low-tech and slow. It can only be produced as pre-cast or prefabricated blocks and panels; itcannot be poured on site like traditionalconcrete. With its light-transmitting properties,however, translucent concrete has the powerto potentially transform the interior of concrete

Figure 1: Optical Fibres

Material Performance

• Concrete embedded with optical glassfibers running in a matrix while still retainingthe strength of concrete.

• High density top layer concrete

• Infused with optical fibers

• Frost and deicing salt resistant

• Fire protection classification A2

• Highest UV resistance

HOW TRANSPARENTCONCRETE MADE1. Strands of optical fibers are cast by the

thousands into concrete to transmit light,either natural or artificial, into all spacessurrounding the resulting translucent panels.Light-transmitting concrete is produced byadding 4% to 5% optical fibers (by volume)into the concrete mixture. The fibers runparallel to each other, transmitting light

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buildings, making them appear fresh, openand spacious.

• Decorative Tiles

• Lamps

Blocks of LiTraCon can be produced indifferent sizes, giving builders a wide varietyof options when working with the material. Sofar, the blocks have been used in manybuildings, for everything from desks to interiorand exterior walls to lamps, and even anoutdoor memorial. The material transmits lightup to 20 m, so the concrete can be very thickwhile still making use of its light transmittingcapabilities. The possible uses for LiTraConare nearly endless. The blocks may even beused in the construction of energy-smarthomes to reduce electricity costs by allowingmore daylight to penetrate the structure.

ENVIRONMENTAL IMPACTWhen a solid wall is imbued with the ability totransmit light, it means that a home can usefewer lights in their house during daylight hours.Since the insulating capacity of the wall isunchanged, the result is a net energy gain.

A GLOWING FUTURESeveral years ago, the material was featuredin the “Liquid Stone” exhibit at the NationalBuilding Museum, and started openingpeoples’ eyes to all kinds of possibilities. Whilethe material has distinct architectural andinterior design appeal, some of the companiesinvolved in l ight-transmitting concreteproduction envision using the distinct looks andunique abilities of this concrete for practicalapplications. Although translucent concrete hasbeen used primarily as an interior decoration,its creators have “visions of cities that glowfrom within, and buildings whose windows need

Figure 2: Exampleof Transparent Concrete

Traditional Uses

• Translucent blocks suitable for floors,pavements and load-bearing walls

• Facades, interior wall cladding and dividingwalls based on thin panels.

Emerging Uses/Trends

•· Partitions

• Furniture

• Light fixtures

• Light sidewalks at night

• Increasing visibility in dark subway stations

• Lighting indoor fire escapes in the event ofa power failure

• Illuminating speed bumps on roadways atnight

• Stairs

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not be flat, rectangular panes, but can bearbitrary regions of transparency within flowing,curving walls”. It can at the same time bebuilding material and light source, can separateand connect, can be wall or floor, ambientlighting or eye-catcher. Translucent concrete isalso a great insulating material that protectsagainst outdoor extreme temperatures whilealso letting in daylight. This makes it an excellentcompromise for buildings in harsh climates,where it can shut out heat or cold withoutshutting the building off from daylight. It can beused to illuminate underground buildings andstructures, such as subway stations. Translucentconcrete could provide safety applications inthe future such as speed bumps that could belit “from below to make them more visible atnight”, or to light indoor fire escapes in case ofa power failure. It even has the potential to besustainable; the aggregate can be replacedwith crushed recycled glass.

CONCLUSIONTranslucent concrete is one of the mostinteresting new takes on the historically stiffand uninspiring building material. It could beused almost anywhere glass or traditionalconcrete are used. Translucent concretecombines the fluid potential of concrete withglass ability to admit light, and it also retainsprivacy and can be used as structural support.The possibilities for translucent concrete areinnumerable; the more it is used, the more newuses will be discovered. As with any newmaterial, it is expensive and still has someissues to be resolved .In the next few years,as engineers further explore this exciting newmaterial, it is sure to be employed in a varietyof interesting ways that will change the opacityof architecture as we know it.

REFERENCES1. Allen E and Iano J (2009), “Concrete

Construction”, Fundamentals of BuildingConstruction: Materials and Methods,Fifth Edition, Hoboken, New Jersey, JohnWiley & Sons Inc. , Ch. 13, pp. 515-551.

2. Goho A (Jan. 1, 2005), “Concrete Nation:Bright future for ancient material”,Science News, Vol. 167, No. 1, p.7.Available: http://www.concretewashout.com/downloads/Concrete_Nat ionScience_News_Online,_Jan._1,_2005.pdf

3. Hartman C (July 7, 2004), AssociatedPress, Seeing the Future of ConstructionThrough Translucent Concrete. SeattlePI, Available http: //www.seattlepi.com/business/article/Seeing-the-future- of-construction-through-1148906.php

4. How to see through walls: Transparentconcrete is encouraging architects torethink how they design buildings. TheEconomist. Sept. 20, 2001. Available:http://www.economist.com/node/779421.

5. Italcementi Group, Available:http://www.i ta lcement igroup.com/ENG/Media+and+Communication/News/Corporate+events/20100322.htm

6. Liquid Stone: New Architecture inConcrete. Exhibition at the NationalBuilding Museum. Available: http://www.nbm.org/exhibitions-collections/exhibitions/liqui d-stone.html

7. LitraCon, available: http://www.litracon.hu/projects.php

8. Lucem, available: http://www.lucem.de/index.php?id=156&L=1