The twin wall technology is a precast concrete wall system that combines the speed of erection of precast concrete with the structural integrity of cast-in-place concrete. It consists of two precast concrete leafs separated by cast-in-place lattice girders. On the construction site, the precast wall units are placed, temporarily propped, then the gap is filled with concrete to form a solid, monolithic wall. The twin wall system provides structural reliability while allowing for faster construction compared to traditional cast-in-place walls.

1. Twin wall technology
Presentation by Somesh. M
Shivani .G
Rakshita .K

2. DEFINITION
The twin wall technology is a solution of wall system that combines the qualities of erection speed and precast
concrete with the structural integrity of in-situ concrete. This type of wall system guarantees structural integrity
and is a more reliable form of construction.
1. Twin wall construction system is a walling system that combines
the speed of erection and quality of precast concrete with the
structural integrity of the in-situ concrete to provide a hybrid
solution.
2. Twin wall is an adaptive wall system that provides the speed
and the effectiveness of the precast concrete with the
structural and water proof reliability.
3. The prefabricated structures comprises of two slabs separated
and connected by the cast-in lattice girder .
4. The units are placed, temporarily propped and then joined by
reinforcing and concreting the cavity on site.
5. Twin wall is usually employed in association with the precast
concrete flooring.

3. HISTORY
Joseph Monier (1823 – 1906) was a gardener and his idea was to develop permanent planters at a low price. In
1867, he patented different products made of reinforced concrete. After his invention of reinforced concrete
the next logical step was the invention of precast concrete elements because prefabrication has great
advantages compared with in-situ concrete (quality, speed, health and safety).
This led to the first precast structure , which were solid in its form and were connected to each other by grouting,
welding and bolting.These led to the development of uniform planning and added to the high seismic loads in
high- rise buildings.
1. The development of the “new” precast structures started in the 1965-1985 , which gave flexibility to the
construction process.
2. Precast girders were one of the first precast elements. This was the starting point for the industrial
production of precast elements on a broad basis.
Development of the double wall
The driving factor for a further development was the need to optimize the building process and cut down
work on the building site, as well as to increase the quality of the product and buildings. In the years from
1980 to 1985, the half precast wall, the so-called twin wall, was invented and introduced to the market.
1. Then came the development of the “new” industrial precast systems.
This developed the CAD/CAM controlled production wherein the CAD was used to generate the
electronic data of the product and PLC systems to control automated machines. This process was used to
develop precast structures faster and with more precision.

4. DEVELOPMENT AND POPULARITY
Since the year 2000, there has been a number of developments dealing with the digitalization and
networking of production. In parts, these methods are already used, but not on a broad scale and not
in every country. Please find below a short overview of the methods and concepts.
BIM - Building Information Modeling
For some years, everyone has been talking about the term BIM. BIM is short for Building Information
Modeling and deals with the exchange of data and information for the design, construction and
maintenance of a building. By letting all persons involved access to the same data, BIM ensures data
consistency, which saves time and money. If any of the involved persons changes data, this is
immediately visible for all the other involved parties and mistakes can be prevented.
“Industry 4.0”
“Industry 4.0” is also one of the terms that are excessively used in the industry. The utilization of
automated machines in the production process is complemented by a connection of the machines
and plants with each other and the internet. Sometimes this principle is also called "smart factory".
Paperless production
In addition to that, some efforts have been made lately to reduce the utilization of paper in the
production of precast concrete elements. Data are to be be transferred only digitally in the future and
printing won't be necessary anymore. This is advisable for environmental, as well as economic reasons.
Moreover, the most recent plans are available at any time.

5. INSTALLATION PROCESS
Precast Concrete Twin Wall combines the dimensional accuracy and quality control of precast walls
with the flexibility of in-situ concrete. The Twin Wall arrives on site as two leaves tied together with steel
lattice girder and is filled with in-situ concrete on site. The final wall is a solid concrete wall with a high
quality paint-ready finish on both sides.
The twin wall system has two walls slabs that are separated. The two slabs are separated by a cast in
lattice girders. The procedure involves:
1. The wall units are placed in the site.
2. The twin units are propped temporarily.
3. The wall units are later joined by means of reinforcing.
4. The gap between the wall units are filled by means of concrete.
This system of construction is faster than normal construction methods and economical.

12. KEY FEATURES
● Innovative Precast Twin Wall System, designed to meet the highest of engineering standards in the construction
industry
● Consists of two 70mm thick precast leafs with high quality smooth external finish and chamfered edges
● Panel sizes up to max 3.0m x 9.5m and weighing up to 10 ton with thicknesses ranging from 200mm to 400mm
● High strength reinforced concrete to EN 206 used in all Twin Walls
● Acoustic Properties - Typically 50 DB reduction for 200mm Twin Wall
● "Paint Ready" Precast Concrete Twin Walls are cured in the factory

13. ADVANTAGES
● The advantages of off-site construction with factory tolerances and high quality factory finishes
● The structural integrity equivalent to any in-situ designs
● The high levels of acoustic control and fire ratings that cannot be achieved by any other precast
system
● Reduced staff on site - less operatives required for erecting walls
● The pre-installation of electrical conduits and outlets during production provides for faster construction
of a building
● The speed of erection and certainty of programmed schedules
● The finished precast structure will have a monolithic quality that is unique to twin wall and will provide
superior levels of air tightness

14. APPLICATIONS
● Precast Concrete Twin Walls are ideal for use in Cross-wall Construction, Hotels, Nursing Homes and
Apartments, and when combined with Filigree slabs they provide a complete monolithic “Paint-
Ready” structure.

16. Video link https://www.youtube.com/watch?v=LGTj6TswAO8
https://www.youtube.com/watch?v=GAkDRKTFbrU
THANK YOU