This document summarizes the key aspects of translucent concrete, also known as light transmitting concrete or LitraCon. It was first developed in 2003 by Hungarian architect Aron Losonzi. The concrete becomes translucent through the uniform distribution of thin optical fibers throughout the material. As light passes through the fibers, it is transmitted across the concrete through the process of total internal reflection. The manufacturing process involves casting thousands of parallel optical fibers directly into the concrete mixture. This allows light to pass through the material while maintaining its compressive strength. Some applications of translucent concrete include illuminated sidewalks, building walls, and stairwells.

1. Mithilesh Mandal
114ar00006
Department of Planning and Architecture
National Institute of Technology Rourkela

2. Introduction
 In 2001 the idea of transparent concrete was put
forward by Hungarian architect Aron Losonzi.
Successfully produced the first transparent concrete
block in 2003,named LiTraCon.
 Light transmitting concrete (LiTraCon) also known as
translucent concrete, is a concrete based building
material having light transmitting property.
 Light transmitting property is mainly due to uniform
distribution of optical fibres throughout its body. It is
also known to be transparent concrete.
 It is available as prefabricated building blocks and
panels.

3. Principle
 Translucent concrete works based on “Nano-Optics”.
 These fibres pass as much light when tiny slits are placed directly on top of
each other. Hence optical fibres in the concrete act like the slits and carry
the light across throughout the concrete.

4. Optical Fibre
 Flexible, transparent fibre made up of glass or plastic (as thin as a human hair).
 It transmits light between two ends of the fibre by process of total internal reflection.
 Optical fibre transmits light so effectively that there is almost no loss of light conducted
through the fibres.

5. Working Principle
 Total Internal Reflection
 When a ray of light travels from a denser to a rarer medium such that the
angle of incidence is greater than the critical angle, the ray reflects back into
the same medium this phenomena is called total internal reflection.
 In the optical fibre the rays undergo repeated total number of reflections
until it emerges out of the other end of the fibre, even if the fibre is bent.

6. Materials Required
 Cement: Ordinary Portland cement is used for transparent concrete.
 Sand: The size of sand should pass through 1.18mm sieve.
 Water: The quality of water should be potable water.
 Optical fibres: The thickness of the fibres should be 2 μm to 2mm.
+ =
Concrete
Optical
Fibre
Light Transmitting
Concrete

7. Manufacturing Process
 Concrete mixture is made up of fine materials only, it contains no coarse
aggregate.
 Strands of optical fibres are cast by thousands into concrete.
 Light-transmitting concrete is produced by adding optical fibres into the
concrete mixture.
 The fibres run parallel to each other.
 Thickness of the optical fibres can be varied between 2 μm and 2 mm
according to the requirements.

8. Manufacturing Process (contd.)
 The most important requirement for the success of the product is assurance
the fibre 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 fibre
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
accordingly.

9. 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 fibres from 0% to 3%
8) Portland cement from 0% to 15%

10. Manufacturing of translucent concrete
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.

11. Properties
 a) Technical specifications
• Form: prefabricated blocks / panels
• Components: Concrete, Optical
fibre
• Cast Material: Fibre 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 fibres
• 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.

12. Advantages and Disadvantages
 Advantages
1) Less energy consumption.
2) Illuminated Pavements.
3) Homogeneous in structure.
4) Finishing Surface.
5) Routine maintenance not
required.
6) Saves electricity by emitting
light during day
7) . Translucent concrete can
enhance security in places where
people and their actions can be
seen, but not their entire image.
 Disadvantages
 1)Very high cost about USD
1000/sq.m of 25mm thickness.
 2) Labours with technical skills are
needed to use it.
 3) It’s a factory product.

13. Applications
 1. Translucent concrete
inserts on front doors of
homes, allowing the resident
to see when there is a person
standing outside.
 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
daylight.

14. Examples
 CELLA SEPTICHORA /
PECS,HUNGARY
Cella Septichora Visitors Centre in
Pécs, Hungary, which has a door made
of Litracon Panels set in a steel frame.

15. Examples
 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, Montblanc.

16. THANK YOU