This document discusses 3D printing with concrete. It provides several examples of projects using 3D printing for construction: (1) A university developed a process to 3D print the walls of a house in 24 hours using a large transportable printer; (2) A Chinese firm used 3D printers to construct 10 small houses in less than 24 hours for less than $5,000 each; (3) The first pedestrian bridge printed entirely in 3D concrete was inaugurated in Spain in 2016. The technology allows optimizing material use and maximizing structural performance.

1. 3D PRINTING CONCRETE
BY
S BALAJI BE, ME, MBA..
ACR INNOVATIVE DESIGN INDIA

2. 3D PRINIT CONCRETE LIVE

3. 3D PRINITING MACHINE FOR
CONCRETE

4. EXAMPLES OF
PROJECT
 In 2014, engineers at Arup used 3D
printing to fabricate a steel
 Professor Behrokh Khoshnevis at the University of
California has developed a process of 'contour crafting'
using concrete to produce small-scale models of the
external and internal walls of houses and is testing a
giant transportable 3D printer that could be used
to build the walls of a house in 24 hours.
The robotic system requires
a flat ground slab with underground services in place.
Rails are installed either side of the footprint to take
a gantry crane that spans the building. A nozzle, driven
by a computer-controlled crafter then
delivers layers of concrete. The layers build up
to form an inner and outer skin for each wall, leaving
them to be filled later with insulation or concrete.

5. EXAMPLE OF PROJECT
 Shanghai firm
WinSun Decoration Design Engineering has used
large 3D printers to spray a mixture of quick
drying cement and recycled raw materials (ref. BBC).
This has enabled them to construct 10 small
demonstration 'houses' in less than 24 hours. They
have suggested that each house can be printed for
less than $5,000. Their system fabricates blocks off-
site by layering the cement mix in a diagonally
reinforced pattern. The blocks are
then assembled on site. Winsun believes it will be
possible to use the technique
to build larger houses or even skyscrapers in the
future. In 2015, they announced they had printed

6. EXAMPLE OF PROJECT
 A Dutch project is fabricating a full-sized
printed house over a period of years in order to
demonstrate the potential of the
new technology (Ref. BBC 3 May 2014).
 In July 2014, Chinese company, Qingdao
Unique Products Develop Co unveiled the World's
largest 3D printer at the World 3D
Printing Technology Industry Conference and
Exhibition in Qingdao. Its first job will be to print a 7
m-high Temple of Heaven. (Ref. Construction
Manager 1 July 2014.)
 In November 2014, Skanska and
Loughborough University signed a deal to develop
what they describe as the world's first
commercial concrete printing robot. (Ref. Construction
Enquirer, Skanska to print 3D concrete products.)

7. EXAMPLE OF PROJECT
 In Spain, the first pedestrian bridge printed in 3D in the world
(3DBRIDGE) was inaugurated on 14 December 2016 in
the urban park of Castilla-La Mancha in Alcobendas, Madrid.
The 3DBUILD technology used was developed by ACCIONA,
who was in charge of the structural
design, material development and manufacturing of 3D printed e
lements. The bridge has a total length of 12m and a width of
1.75m and is printed in micro-reinforced concrete. Architectural
design was done by the Institute of Advanced Architecture of
Catalonia (IAAC).
 The 3D printer used to build the footbridge
was manufactured by D-Shape. The 3D printed bridge reflects
the complexities of nature’s forms and was developed
through parametric design and computational design, which
allows optimising the distribution of materials and maximising
the structural performance, being able to dispose
the material only where it is needed, with total freedom of forms.

8. THANK YOU
ACR INNOVATIVE DESIGN INDIA