Light Transmitting Concrete
• Concrete is one of the world’s widely used building
• And builders have been using concrete for thousands of
• Introduction of fiber optics into the concrete mix has
given it a new dimension.
• Now, it seems as if the days of dull, grey concrete are
about to end.
• Litracon is a light-transmitting or translucent concrete
which is able to move light through concrete up to 20
• It is a strong ,solid material through which light can be
• Light-transmitting concrete can be used in variety of
• Litracon was invented by an architect from Hungry, Aron Losonczy.
• He saw an art at Budapest, which was made up of ordinary concrete and
• From here, he thought of combining the two materials together.
• In 2001, successfully a Litracon block was produced.
• Aron Losonczy named his invention “LITRACON”, short for light
• And in 2004, he started a German company named Litracon Bt. and started
producing Litracon commercially.
• Flexible, transparent fiber made up of glass or plastic (as thin as a human hair).
• It transmits light between two ends of the fiber by process of total
• Optical fiber transmits light so effectively that there is almost no loss of
light conducted through the fibers.
PRINCIPLE OF OPERATION
Optical fiber is made up of three sections:
1) CORE –(carries light signals) thin glass center of fiber where light travels
2) CLADDING –(keeps light in the core) made of a material which has a lower
refractive index than the core(for light to pass from the core out through the
cladding, it would have to slow down). Instead, the light waves takes the path of
least resistance by reflecting only in the core.
3) COATING –(protects the cladding) Plastic
coating that protects the fiber from damage.
• Concrete mixture is made up of fine materials only, it contains no coarse
• Strands of optical fibers are cast by thousands into concrete.
• Light-transmitting concrete is produced by adding 4% to 5% optical fibers
(by volume) into the concrete mixture.
• The fibers run parallel to each other.
• Thickness of the optical fibers can be varied between 2 μm and 2 mm
according to the requirements.
• The most important requirement for the success of the product is
assurance the fiber optic strands make contact with both surfaces; otherwise
it looses the ability to transmit.
• An uninterrupted passage through the concrete is achieved by using long
moulds, which are filled with a thin layer of concrete, before layers of fiber
optic strands and more concrete are added until the mould is full.
• From the long moulds, the product can be removed, and then cut to length
MIXING OF CONCRETE
• COMPONENTS OF CONCRETE
1) Epoxy matrix from 0% to 90%
2) Polycarbonate matrix from 0% to 60%
3) Fiberglass from 0% to 10%
4) Colloidal silica sol from 0.5% to 5%
5) Silica from 0.5% to 10%
6) Diethylenetriamine (DETA) from 10% to 50%
7) Optical fibers from 0% to 3%
8) Portland cement from 0% to 15%
A manufacturing process for translucent concrete ,comprises of following stages:
a)Mixing the cement with water according to specific proportions.
b)Mixing the polymer matrices with the respective catalyst or hardener, and
c)Mixing the previous two mixtures with the other components in the specific proportions.
The ratio of the polymer matrices and the mortar is at least 1.5:1, and the mixing is done
manually or mechanically. The epoxy matrix or binder used for the formulation of this concrete
is diglycidyl ether of bisphenol A (DGEBA). The setting agent used is diethylenetriamine
(DETA).Silica sol functions as a binding agent.
2. In the second step, layer of fibers are arranged in the longitudinal
direction of the mould.
1. Firstly, in an elongated mould e.g. steel or wood, concrete mix is added.
2. In the third step, the mould is subjected to a mechanical pressure and/or
vibration such that the fiber layer is permitted to sink into the cast
material to a desired depth.
3. Then, steps one to three is repeated, alternatively steps two to three,
until the mould is filled with the cast material and several fiber layers
4. Each layer constitutes of a plurality of parallel fibers, for example some
twenty fibers or more per layer.
5. The thickness of the layer and the fibers may suitably be about 1 mm
and the number of layers can be some twenty or more.
6. The fiber layers are fed continuously in the mould from a fiber roll via a
nozzle that provides for an even distribution.
7. When the cast material has become solidified, the solid moulded body is
divided by cutting into separate building blocks.
a) Technical specifications
• Form: prefabricated blocks / panels
• Components: Concrete, Optical fiber
• Cast Material: Fiber Ratio: 1:15 to 1:8
• Density: 2100 – 2400 kg/m3
• Compressive strength varying
• Bending Strength: 7.7 N/mm2
b) Material performance
• Concrete retains its strength
• High density top layer concrete
• Infused with optical fibers
• Frost and de-icing salt resistant.
• Fire protection.
• Highest UV resistance.
c) Environment Impact
• When a solid wall has the ability to transmit light, it means that
one can use fewer lights during daylight hours.
1) Less energy consumption.
2) Illuminated Pavements.
3) Homogeneous in structure.
4) Finishing Surface.
5) Routine maintenance not required.
1)Very high cost about EUR 1300/m2.
2) Labours with technical skills are needed to use it.
3) It’s a factory product.
Litracon building units are applicable in various areas of design.
1. Translucent concrete inserts on front doors of homes,
allowing the resident to see when there is a person standing
2. Translucent concrete walls on restaurants, clubs, and other
establishments to reveal how many patrons are inside.
3. Ceilings of any large office building or commercial structure
incorporating translucent concrete would reduce lighting
costs during daylight hours.
4. Sidewalks poured with translucent concrete could be made
with lighting underneath, creating lit walkways which would
enhance safety, and also encourage foot travel where
previously avoided at night.
5. The use of translucent concrete in an outer wall of an indoor
stairwell would provide illumination in a power outage,
resulting in enhanced safety.
6. Subways using this material could be illuminated with
1) THE EUROPE GATE
It is located in Fortress Monostor in the
Hungarian town Komarom by the Danube
River. The sun illuminates the 37.6ft2
large Litracon piece of the statue in the
mornings and late afternoons, and by night
an even more impressive view can be seen
because of the embedded light sources.
THE EUROPE GATE
2) CELLA SEPTICHORA / PECS,
Cella Septichora Visitors Centre in Pécs,
Hungary, which has a door made of
Litracon Panels set in a steel frame.
3) MONTBLANC, TOKYO
The illuminated interior wall of the
new boutique of Montblanc in Tokyo is
considered to be the most prestigious
project of Litracon up-to-date. Litracon
blocks were used as illuminated wall in the
new flagship boutique of famous producer
of handwriting instruments and jewellery,
• Light transmitting concrete or translucent concrete is an emerging
trend in concrete technology. It’s considered as a special concrete
which ensures future benefits.
• Its initial cost is high. But, routine maintenance is not required and in
long run it may be advantageous.
• It’s a green building material reducing the lightning cost during day
time. It’s proved to provide both aesthetic appearance and structural
• LTC blocks can be used to build up to 20m high load bearing walls.
•If the price of the product gets reduced, it is sure that the future
construction industry will be in the hands of Litracon.
• It is one of the best applications of optical glass fibers which isrelated
to technical textiles.