Mastercivilengineer

What is Transparent Concrete?

Transparent concrete is hardened concrete that allows light to pass through it. It is also known as light-transmitting concrete or translucent concrete.

Commonly, transparent concrete is similar to ordinary concrete because the strength of both concrete is similar. But the major advantage is the transparent concrete is costly compared to normal concrete.

The main function is to use sunlight as a light source to reduce power consumption and to use optical fiber as an architectural purpose for a good aesthetic view of the building.

As an energy-saving & eco-friendly building material, light-transmitting or translucent concrete is now increasingly used in fine architecture and cladding for interiors.

History of Transparent Concrete

• The idea of transparent concrete was founded by Hungarian architect Aron Losonczi in the year of 2001 and successfully produced in 2003.
• In 2004, he started a German company, named LiTraCon (Light Transmitting Concrete) and started manufacturing transparent concrete commercially.
• It was available in floors, pavements, ceiling, load-bearing walls, partition walls, etc. It was available as prefabricated blocks and panels.
• Light-transmitting property is mainly due to the uniform distribution of optical fibers throughout its body. It was a new technique different from ordinary concrete.
• Transparent concrete allows more light and less weight compared to normal concrete.
• This concrete works on ‘Nano-optics’ and fibers act as aggregates and carry light through them, the fibers are placed directly on top of each other.

Materials Used for Transparent Concrete

• There are two primary materials used for manufacturing the transparent concrete, one is from the construction field and another from the sensing field.
• The first one is concrete, which is one of the most important civil engineering materials with the advantages of rich raw materials, low cost, and simple production process.
• And the second is the optical fiber has good light guiding property which can be arranged to transmit the sunlight according to pre-design study and stress distribution of structures.
• By merging the benifits of concrete and optical fiber, developing a novel functional material called transparent concrete has an important value in the application of construction and sense.
  • Cement
  • Sand
  • Water
  • Optical Fiber

Cement

• Cement is a fundamental and most important material for any concrete. Cement is a principal material that is utilized for a better bond between the aggregate & another material of concrete.
• In translucent concrete the optical fiber is only responsible ingredient for transmission light from concrete, so no special type of cement is required.
• Ordinary Portland cement (OPC) is commonly used everywhere, therefore this cement is used for transparent concrete. Cement is available in different grades like 33, 43, 53 and available at different prices.

Sand

• The translucentconcrete is made by only fine material or fine aggregate (sand), the size of sand should pass through a 1.18mm sieve.
• The fine material is free of impurities because this material is inert material means should not take any reaction. For example, alkali-aggregate reaction, etc.

Water

• The water used for transparent concrete should be potable or drinkable quality water. Water should be free from any other impurities. The water usedshould be clear and has ph of water lies between 6.5 to 8.5.

Optical Fiber

• The optical fiber is the thin fiber of plastic or plastic that transmits light from one point to another point. The analysis of the optical fiber principle is known as fiber optics. Fiber optics is one branch of applied science and engineering.
• In concrete, the volume of optical fiber is up to 4-5% of the total volume of concrete and the thickness of optical fiber is lies between 2microns to 4mm.
• The volume and thickness of optical fiber depend on the purpose of light transmission or the requirement of light transmission.

The optical fiber has three parts:

1. Core
2. Cladding
3. Buffer Coating

Core: The center portion of optical fiber where light travel is called core. The core diameter of optical fiber differs from 5 microns to 100 microns.

Cladding: The outer material of the optical fiber surrounding the core that reflects the light into the core. To enclose the reflection in the core, the refractive index of the core must be greater than that of the cladding.

Buffer Coating: Buffer coating is a plastic coating applied over-cladding to prevent the fiber from moisture and other damages.

Manufacturing Process of Translucent/Transparent Concrete

Following steps are to be followed during the manufacturing of transparent concrete:

Step 1-Mould Preparation

• A mould of the rectangular cross-section 150mm x 150mm x 150mm is made up of wooden or metal.
• To remove mould easily after concreting, place the optical fiber in the soil beside the sides where the optical fibers are in contact with the frame.

Step 2-Optical Fiber

• The optical fiber accurately reduces the required size of the mould.
• The commonly available diameters of optical fiber are 0.25mm. 0.5mm, 0.75mm, 1mm, and 2mm.

Step 3-Fixing the Fiber

• The optical fibers are laid either in an organic distribution or in a layered distribution.
• The holes are driven on wooden or metal plates by which optical fibers are enabled to move.

Step 4-Collapse

• The properly mixed translucent concrete is filled carefully & slowly so that there is no disturbance to the optical fiber already laid.
• Concrete is poured in small or thin layers and mixed with the help of hill tables to avoid void formation.

Step 5-Removing the Mould

• After 24 hours, remove the mould and sludge, the molded mould is laid unattended on a flat platform.
• After that it is carefully removed after 24 hours of casting.
• Then de-molding the cube samples and marked by their respective identification marks.

Step 6-Cutting and Polishing

• Remove the extra-long fibers, the same as the thickness of the panel.
• Brighten or polish the panel surface using polishing paper or using sandpaper.

Properties of Transparent Concrete

Product	Light Transmitting Concrete (LiTraCon)
Form	Prefabricated block
Ingredient	96% concrete, 4% optical fiber
Density	2100-2400 kg/m3
Block size	60cm x 30cm
Thickness	25-500mm
Color	White, grey-black.
Fiber distribution	Organic
Finished	Polished
Compressive strength	50 N/mm2
Bending tensile strength	7 N/mm2

Applications of Transparent Concrete

Followings are the applications of Transparent concrete or Translucent concrete:

• Transparent concrete is suitable for the floors, pavements, and load-bearing walls.
• To provide for the decorative and aesthetic function.
• It improves the visibility in dark metro stations.
• If there is a power failure, the light escapes from the indoor fire.
• Highlighting the roads at night in roadways.
• To watch your pavement shine at the time of sunset.
• To get creative with the design.
• Dividing walls based on facades, internal wall cladding, and thin panels.
• A partition wall with transparency can be utilized where daylight doesn’t reach properly.
• It is used in lighting fixtures also.
• To use as transparent and decorative floors.

Advantages of Transparent Concrete

Followings are the advantages of Transparent concrete or Translucent concrete:

• It has excellent architectural qualities to give a stunning aesthetic view of the building.
• When the concrete wall is permitted with the ability to transmit light, it implies that homeowners can use less light in their homes throughout the day.
• The texture is visible, while the fine translucent concrete floor is skewed at some distance
• Where the supply of light is not uniform, transparent concrete can be used.
• Energy-saving can be achieved by utilizing translucent concrete.
• Transparent concrete is environmentally friendly due to its light-transmitting properties to reduce energy consumption.
• It has very good architectural properties for giving a good aesthetical view of the building.

Disadvantages of Transparent Concrete

Followings are some disadvantages of Transparent concrete or Translucent concrete:

• The main drawback of transparent concrete is very costly because of the optical fibers.
• The manufacturing of transparent concrete blocks is complicated, so it mostly requires a skilled person.