1. Department of Civil and Building Engineering
INVESTIGATING THE BARRIERS TO ENTRY AND BENEFITS OF
3D CONCRTE PRINTING IN THE ARCHITECTURE,
ENGINEERING AND CONSTRUCTION INDUSTRY
Submitted by: Benjamin Yolen Cohen
Student ID: B414924
Dissertation Research Report
In partial fulfillment of the degree MSc. Construction Project
Management
(2014-2015)
Supervisor: Dr. Richard Buswell
24th
of September 2015

3. II
CERTIFICATE OF OWNERSHIP
I certify that:
I am the sole author of this dissertation research, prepared by me for the MSc
Construction Project Management, and that any assistance received in its preparation is
clearly acknowledged and disclosed in the report.
I have cited correctly any sources from which I have used data, illustrations, ideas or
words, either in the form of direct quotation or paraphrased.
Name: Benjamin Yolen Cohen
Signature:
Date: 24th
August 2015

5. III
ACKNOWLEDGEMENTS
Firstly, I would like to thank Dr. Richard Buswell, Nikolaos Konstantinidis and the rest of
the 3D Concrete Printing Consortium for their help, guidance and inspiration throughout
the research and writing of this dissertation. I would also like to offer my sincere thanks to
my parents, Jeffery Cohen and Malerie Yolen-Cohen, and my friends Jaime Sancho
Garcia and Caroline Casati, who provided moral support and were always there with
advice. Lastly, I would like to thank all those who took the time to participate in my
interviews and provide valuable insights with their responses.

7. IV
ABSTRACT SUMMARY AND KEYWORDS
The Architecture, Engineering and Construction (AEC) industry is one of oldest and largest
economic sectors in the world, yet over the past 20 years this industry has experienced a
significant shift from traditional design methods to digital modelling. In an industry with
such large financial risks and short timeframes between projects, companies focus on
producing conservative proposals at least cost, leaving little investment of time or
resources for research and development. This lack of innovation has led to the
construction industry falling decades behind similar industries such as aerospace,
automotive and shipbuilding. Alternatively, this transition towards increasing technology-
based solutions has given architects and designers the ability to create geometries and
structures that were not possible in the past. These architect’s buildings are changing the
perception of what is fashionable in the industry; increasing the gap between what can be
designed and what can be built. The manufacturing industry has become the bottleneck to
innovative architecture, falling far behind the design intent and demands of architects and
their clients. 3D Concrete Printing is a large-scale additive manufacturing process with the
aim of closing this gap by providing the ability to produce architectural and construction
components without the requirements of tooling or moulds. This research project
investigates the benefits of this process, as well as the likely barriers, a framework for
adoption and where this technology will potentially find its place in the AEC industry.
KEYWORDS: ARCHITECTURE, ENGINEERING, CONSTRUCTION, INDUSTRY,
TECHNOLOGY, RESEARCH, INNOVATION, RADICAL, DESIGN, 3D CONCRTETE
PRINTING, ADDITIVE MANUFACTURING.

9. V
LIST OF FIGURES
Figure 1: Gartner Hype Cycle (O’Leary, 2008). .............................................................. 12
Figure 2: Process Chart for Building Manufacturing using BIM (Vähä et al., n.d.).......... 15
Figure 3: CIM Hierarchy (Waldner, 1992). ...................................................................... 19
Figure 4: Cost Versus Level of Automation (Gorlach and Wessel, 2008)....................... 21
Figure 5: Process for Automated Precast Concrete Component Fabrication. ................ 27
Figure 6: D-Shape Fabricated Component (Dini, 2013).................................................. 33
Figure 7: D-Shape Complete House Print (Colla and Dini, 2013)................................... 34
Figure 8: Contour Crafting Nozzle Design (Khoshnevisk, 2004)..................................... 35
Figure 9: Contour Crafting created component (Paech, 2014). ...................................... 36
Figure 10: WinSun Concrete Printed Component (Xinhua, 2014). ................................. 37
Figure 11: 3D Concrete Printing Nozzle Design (Gardiner, 2011) .................................. 38
Figure 12: Double-Curved 3D Concrete Printed Wall Panel (Buswell, 2014) ................. 39
Figure 13: Hype Cycle for 3D Printing, 2014 (Van Der Meulen and Rivera, 2014)......... 41
Figure 14: Additive Manufacturing vs. Mould Making (Atzeni and Salmi, 2012). ............ 43
Figure 15: NVivo Coding Example .................................................................................. 62
Figure 16: NVivo Study of Coded Narratives .................................................................. 63
Figure 17: Word Frequency and Text Search Query ...................................................... 63
LIST OF TABLES
Table 1: Interview Participants ........................................................................................ 59

11. VI
LIST OF ABBREVIATIONS
3DCP 3D Concrete Printing
AEC Architecture, Engineering and Construction
BIM Building Information Modelling
CAD Computer Aided Design
CAM Computer Aided Manufacturing
CIM Computer-Integrated Manufacturing

13. TABLE OF CONTENTS
CERTIFICATE
OF
OWNERSHIP
...............................................................................................
II
ACKNOWLEDGEMENTS
...........................................................................................................
III
ABSTRACT
SUMMARY
AND
KEYWORDS
............................................................................
IV
LIST
OF
FIGURES
..........................................................................................................................
V
LIST
OF
TABLES
...........................................................................................................................
V
LIST
OF
ABBREVIATIONS
........................................................................................................
VI
1.
INTRODUCTION
.......................................................................................................................
1
1.1
Background
..................................................................................................................................
1
1.2
Aim
and
Hypothesis
.......................................................................................................................
2
1.3
Objectives
.........................................................................................................................................
2
1.3
Justification
......................................................................................................................................
3
1.4
Method
of
Study
..............................................................................................................................
3
1.5
Summary
of
Main
Findings
.........................................................................................................
4
1.6
Guide
to
the
Report
.......................................................................................................................
5
1.6.1
Chapter
1:
Introduction
..........................................................................................................................
5
1.6.2
Chapter
2:
Literature
Review
...............................................................................................................
5
1.6.3
Chapter
3:
Methodology
.........................................................................................................................
5
1.6.4
Chapter
4:
Data
Analysis
and
Results
...............................................................................................
6
1.6.5
Chapter
5:
Discussion
..............................................................................................................................
6
1.6.6
Chapter
6:
Conclusion
..............................................................................................................................
6
1.6.7
Appendix
A:
..................................................................................................................................................
6
1.6.8
Appendix
B:
..................................................................................................................................................
6
1.6.9
Appendix
C:
..................................................................................................................................................
7
1.6.10
Appendix
D:
...............................................................................................................................................
7
2.
LITERATURE
REVIEW
...........................................................................................................
8
2.1
Introduction
.....................................................................................................................................
8
2.2
Background
of
the
AEC
Industry
...............................................................................................
8
2.3
Innovations
......................................................................................................................................
9
2.3.1
Factors
Leading
Towards
Innovation
...............................................................................................
9
2.3.2
Gartner’s
Hype
Cycle
.............................................................................................................................
10
2.4
Radical
Innovations
in
the
Construction
Industry
...........................................................
13
2.4.1
BIM
................................................................................................................................................................
13
2.4.2
Construction
Robotics
..........................................................................................................................
14
2.5
Parallel
Industries
......................................................................................................................
16
2.5.1
Automotive
Industry
.............................................................................................................................
17
2.5.2
Shipbuilding
..............................................................................................................................................
22
2.5.3
Precast
Concrete
Industry
..................................................................................................................
24
2.6
3D
Concrete
Printing
..................................................................................................................
30
2.6.1
Comparable
Research
...........................................................................................................................
31
2.6.2
The
Model
of
Information
Flow
of
3D
Concrete
Printing
......................................................
41
2.6.3
The
Envisaged
Benefits
of
this
Technology
................................................................................
42
2.6.4
Barriers
to
Overcome
...........................................................................................................................
45
2.7
Conclusion
.....................................................................................................................................
45
3.
METHODOLOGY
....................................................................................................................
48
3.1
Research
.........................................................................................................................................
48

14. 3.2
Research
Design
..........................................................................................................................
48
3.2.1
Quantitative
Research
..........................................................................................................................
49
3.2.2
Qualitative
research
..............................................................................................................................
50
3.3.
Deciding
on
the
Research
Approach
/
Data
Collection
..................................................
51
3.3.1.
Interview
Method
..................................................................................................................................
51
3.3.2
Sampling
.....................................................................................................................................................
53
3.3.3
Literature
Review
...................................................................................................................................
54
3.3.4
Developing
the
Questions
...................................................................................................................
55
3.3.5
Pilot
Study
..................................................................................................................................................
55
3.4
Data
Analysis
................................................................................................................................
56
3.5
Summary
........................................................................................................................................
57
4.
DATA
ANALYSIS
AND
RESULTS
.......................................................................................
58
4.1
Introduction
..................................................................................................................................
58
4.2.
Participants
..................................................................................................................................
58
4.3
The
Interview
...............................................................................................................................
60
4.3.1
Pilot
Study
..................................................................................................................................................
60
4.3.2
Structure
of
the
Interview
..................................................................................................................
60
4.4
Interview
Responses
..................................................................................................................
61
4.4.1
Overall
Process
of
Introducing
a
Radical
Innovation
into
the
AEC
Industry
................
64
4.4.2
Barriers
to
be
Expected
and
How
They
Can
be
Overcome
...................................................
69
4.4.3
Framework
Required
to
Adopt
a
Technology
like
3DCP
......................................................
72
4.4.4
Where
This
Technology
Will
Find
its
Place
in
the
AEC
Industry
.......................................
74
4.5
Summary
........................................................................................................................................
77
5.
DISCUSSION
...........................................................................................................................
78
5.1
Introduction
..................................................................................................................................
78
5.2
Summary
of
Findings
.................................................................................................................
78
5.2.1
Overall
Process
of
Introducing
a
Radical
Innovation
into
the
AEC
Industry
................
78
5.2.2
Barriers
to
be
Expected
and
How
They
Can
be
Overcome
...................................................
81
5.2.3
Framework
Required
to
Adopt
a
Technology
Like
3DCP
.....................................................
83
5.2.4
Where
This
Technology
Will
Find
its
Place
in
the
AEC
Industry
.......................................
85
5.3
Summary
........................................................................................................................................
88
6.
CONCLUSION
..........................................................................................................................
89
6.1
Introduction
..................................................................................................................................
89
6.2
Summary
of
Key
Findings
.........................................................................................................
89
6.2.1
Objective
1
.................................................................................................................................................
90
6.2.2
Objective
2
.................................................................................................................................................
91
6.2.3
Objective
3
.................................................................................................................................................
92
6.2.4
Objective
4
.................................................................................................................................................
93
6.3
Limitations
of
the
Research
.....................................................................................................
94
6.4
Recommendations
to
the
AEC
Industry
...............................................................................
95
6.5
Recommendations
for
Future
Research
..............................................................................
96
REFERENCES:
.............................................................................................................................
97
APPENDIX
A:
DISSERTATION
DEFINITION
FORM
.......................................................
105
APPENDIX
B:
GLOSSARY
......................................................................................................
106
APPENDIX
C:
INTERVIEW
TEMPLATE
.............................................................................
111
APPENDIX
D:
INTERVIEW
TRANSCRIPTS
.......................................................................
115

16. Introduction
1
1. INTRODUCTION
1.1 Background
Over the past 20 years, the AEC industry has experienced a significant shift from
traditional design methods to digital modelling. This transition has left the manufacturing
capabilities of the industry decades behind similar industries, such as aerospace,
automotive and shipbuilding (Ding et al., 2014). This manufacturing bottleneck has
resulted in the standardisation of designs and a growing gap between what can be
designed and what can be built. Additionally, this shift towards digital modelling has
increased the demands of the AEC industry; resulting in the expectation of shorter
timeframes, lower costs and higher quality outputs. With additional pressure from the UK
Government’s 2016 BIM mandate and 2025 industry strategy, it is clear that the AEC
industry is shifting towards being more technology-based, and expecting such
improvements as a 33% reduction of construction costs, 50% faster delivery time and 50%
lower greenhouse gas emissions by 2025 (HM Government, 2013). As leading architects
are “generat(ing) formal and spatial complexity inconceivable only a few years ago”
(Jonathan and Field, 2000), it is clear that a cost and time effective sustainable process
must be developed to close this gap in the manufacturing of architectural and construction
components.
Since 2005, several research and development teams have advanced the process of
large-scale additive manufacturing. 3D Concrete Printing (3DCP), developed at
Loughborough University by Dr. Richard Buswell and Professor Simon Austin utilises a
multi-axis robotic arm and highly viscous concrete mixture with the intention of producing
an alternative to the traditional methods used for the creation of low-volume complex
bespoke components (Lim et al., 2012). Though many additional uses and benefits to this
technology exist in theory, the research is still in its early stages, requiring further
investigation to decipher the need for this technology, a framework for adoption and the
potential market gaps it is likely to fill.
In order to help draw conclusions as they relate to 3DCP, research has been performed
looking into other radical innovations within the AEC sector, such as BIM and construction

17. Introduction
2
robotics and automation, as well as similar industries in order to understand the overall
process, barriers, and framework for adoption this technology must adopt in order to meet
the least amount of resistance possible.
1.2 Aim and Hypothesis
The aim of this project is to evaluate the process of introducing a radical innovation into
the construction industry as well as the commercial benefits of manufacturing components
using 3D concrete printing.
Through the development of the literature review the following hypothesis emerged:
The introduction of 3DCP into the AEC industry is likely to experience the same barriers as
experienced by parallel industries during their transition from craft to digitalisation. Once
adopted, this technology is likely to benefit clients, architects, contractors and engineers
by providing a cost effective method for the production of bespoke architectural cladding
and components.
1.3 Objectives
In order to achieve this aim, the following objectives were set:
• Develop the process of introducing a radical innovation, such as 3DCP into the
AEC industry.
• Determine the barriers that are to be expected when implementing a radical
innovation such as 3DCP, and how they can be overcome.
• Develop a framework for the adoption for 3DCP based on the analysis of parallel
industries and information obtained through qualitative research.
• Determine where 3DCP will find its place in the AEC industry.

18. Introduction
3
1.3 Justification
It has been found in the AEC industry that an increasingly growing gap exists between
what can be designed and what can be built. This gap is the result of the recent shift from
traditional design methods to digital modelling processes, giving architects and designers
the ability to create geometries and structures inconceivable only a few years ago. 3DCP
provides a means of closing this gap, though given the culture of the AEC industry as well
as political and technical issues it is necessary to develop a framework for adoption of this
technology. This research is necessary to understand how a radical innovation such as
3DCP will function within the AEC industry, as well as the path it must take to get there.
This will be accomplished by drawing parallels against similar sectors to see how a
transition like this would take place and what results and benefits would occur. This is
important in order to justify the benefits this technology has to offer as well as determine
where it is likely to find its role within the industry.
1.4 Method of Study
The research methodology selected in this research project included the following:
• Literature review
o Textbooks on innovation, offsite manufacturing, shipbuilding and the
automotive sector.
o Journals containing existing data on 3DCP and comparable methods,
innovation diffusion, the culture of the AEC industry and similar industries.
o Similar research projects on the introduction of automated processes into
the construction industry
• Mono-method qualitative data collection process
o Explorative semi-structured interviews with people knowledgeable in the
architecture, engineering, construction and materials industries
• Thematic data analysis
• Discussion of findings
• The development of conclusions to the project aim and objectives specified for this
dissertation.

19. Introduction
4
1.5 Summary of Main Findings
After successfully completing the methods of study described above, the key findings were
obtained from the thematic analysis of the literature review and narratives collected
through the interview process. These findings are presented as follows:
• With a push from clients as well as the UK Government’s 2011 mandate, the AEC
industry is shifting towards a more technology-based profession, leading to an
increase in offsite manufacturing and automation.
• This shift is also affecting the types of people attracted to the AEC industry,
causing the culture to slowly shift as well.
• Several companies, such as Laing O’Rourke, have already adopted automated
fabrication processes into the industry with varying degrees of success.
• Barriers to the adoption of automation experienced by the parallel industries
included the steep price of the robotics, the limitations of these processes given the
bespoke nature of projects, political will, difficulty-integrating equipment into
standard processes and the resistance to change culture experienced by each of
these industries.
• Barriers as summarized by the participants interviewed are an industry wide lack of
education on the subject, lack of design codes and specifications, the short
timeframes between projects and lack of investment into research and
development and the aging of those in leadership roles in the industry.
• In order for the AEC industry to adopt 3DCP it must not only prove that the process
works, but that its already been used on past projects with success.
• Additionally, 3DCP must advertise the process, not only within the industry but
publicly in order to gain attention from clients. Clients are likely to be a major
driving force of this technology, pushing contractors to adopt this technology.
• Contractors are likely to be the main party responsible for owning this technology,
maintaining the machines and absorbing all associated costs.
• In order for 3DCP to succeed there must be collaborative ventures established to
reduce the potential risks on each stakeholder.
• By lining the benefits of this process up with targets and mandates established by
the government it is likely to gain more traction.

20. Introduction
5
• Given this wide arrangement of potential uses, as well as the fact that these ideas
have changed very little in the past ten years, it is clear that this research is still in
its infancy and a clear vision of where this technology will find its place has yet to
be fully established.
• The most common consensus is the ability to produce cladding panels and
building envelopes optimised for their function. This is likely the path this
technology will follow and the form it will take when it is first introduced to the
industry
•
1.6 Guide to the Report
1.6.1 Chapter 1: Introduction
Chapter 1 gives an overview of the background, aim and hypothesis, objectives,
justification, methods of study and summary of key findings of the research. The project
definition form can be found in Appendix A.
1.6.2 Chapter 2: Literature Review
Chapter 2 provides a background on the academic, industry and other relevant literature to
3DCP, radical innovations in the construction industry and an investigation into parallel
industries that have gone through a similar transformation from traditional to automated
processes.
1.6.3 Chapter 3: Methodology
Chapter 3 critically evaluates several research methods in order to devise a specific
methodology that appropriately achieves the aims of this dissertation.

21. Introduction
6
1.6.4 Chapter 4: Data Analysis and Results
Chapter 4 exhibits and analyses the data collected through the mono-method qualitative
research approach. This involves a thematic analysis of common themes as they relate to
the research objectives.
1.6.5 Chapter 5: Discussion
Chapter 5 synthesises the data presented in the previous chapter, interweaving the
analysis of the interview narratives with points made in the literature review. The purpose
of this discussion is to fill in the gaps left by assumptions made in the literature review with
the narratives provided by a wide spectrum of members of the AEC industry.
1.6.6 Chapter 6: Conclusion
Chapter 6 displays the conclusions drawn as they relate to the main research objectives.
Each point is analysed independently in order to determine the key findings of the
research.
1.6.7 Appendix A:
Appendix A contains the dissertation definition form, including the project aims, objective,
justification for research, proposed research methods and sources of data.
1.6.8 Appendix B:
Appendix B contains a glossary, providing a consistent definition for several underpinning
technologies used in this dissertation. Each term includes a general definition as well as its
relation to the construction industry and research.

22. Introduction
7
1.6.9 Appendix C:
Appendix C contains the interview template utilised during each interview. This includes a
description of the study, the expected benefits, a note on confidentiality, a statement of
consent and the established interview questions.
1.6.10 Appendix D:
Appendix D contains the interview transcripts from all nine participants. Each transcript
has had the name of the company and participant redacted as per the confidentiality
agreement.

23. Literature Review
8
2. LITERATURE REVIEW
2.1 Introduction
The purpose of this chapter is to review academic, industry and other literature relevant to
3D Concrete Printing (3DCP), radical innovations in the construction industry and an
investigation into parallel industries that have gone through a similar transformation from
traditional to automated processes. This literature review first looks at the background of
the AEC industry, innovations and their role in this industry, then at past radical
innovations and their process to adoption. The paper then reviews similar industries, their
transition from craft to digitalisation and the impact of automation on their work processes,
supply chain and profitability. With all this information established, the research focuses on
3DCP as well as comparable research in order to distinguish the benefits specific to 3DCP
as they exist today. Lastly, an investigation is preformed into the envisaged benefits of
large-scale additive manufacturing as well as the potential barriers. A definition of the
underpinning technologies is located in Appendix B, establishing a series of definitions of
key terms that remain consistent throughout the research. This literature review seeks to
establish a base of knowledge on which to build the methodology and research.
2.2 Background of the AEC Industry
The construction industry is one of oldest and largest economic sectors in the world, yet
the building procurement process has changed very little over the past eight hundred
years (Balaguer and Abderrahim, 2008). In an industry with such large financial risks and
short timeframes between projects, companies focus on producing conservative proposals
at least cost, leaving little investment of time or resources for research and development.
This lack of innovation has led to the construction industry falling decades behind similar
industries such as aerospace, automotive and shipbuilding (Ding et al., 2014). Although
construction manufacturing technologies have received little innovation, the AEC industry
has experienced a significant shift from traditional design methods to digital modelling over

24. Literature Review
9
the past 20 years (Vollers and Rietbergen, 2007). This transition has given architects and
designers the ability to create geometries and structures that were not possible in the past.
Leading Architects and practitioners, such as Frank Ghery, Zaha Hadid and Foster +
Partners constantly push the boundaries of design and “generate formal and spatial
complexity inconceivable only a few years ago” (Jonathan and Field, 2000). Their
buildings are changing the perception of what is fashionable in the industry; increasing the
gap between what can be designed and what can be built. The manufacturing industry has
become the bottleneck to innovative architecture, falling far behind the design intent and
demands of architects and their clients. In order to close this gap it is clear that new and
innovative processes must be investigated.
2.3 Innovations
2.3.1 Factors Leading Towards Innovation
Despite an innovation’s maturity in the industry, research has shown that leading firms
generally demonstrate resistance to radical technologies, as these tend to disrupt
established products and markets, call for the cannibalisation of previous technologies,
and create an atmosphere of turmoil (Garrison, 2009). Radical Innovations are completely
new concepts or approaches, which often render previous solutions obsolete, including
interdependent components or system. This is the category a technology such as 3DCP
falls under, and usually results in a paradigm shift of a large scale with unpredictable
impacts and a high risk factor (Nelson and Winter, 1977). With all the potential negatives
associated with adopting radical innovations, it calls into question why a large company
would pursue this transition and undertake these risks. Hoed (2007) makes the claim that
there are five change factors that cause large firms to consider this transition and proceed
with it. These change factors are as follows:
1. New entries
2. External shocks or crisis
3. Performance of the new technology
4. Market change

25. Literature Review
10
5. Industry Competition
New entries relates to outside parties, such as entrepreneurs or 3rd
party research teams
that are less constrained by vested interests. This could relate to University research
teams or small independent companies interested in emerging technologies. External
shock or crisis refers to events that cause companies to question current technologies and
ask if they could be done better. This leads to the research and development of radical
new alternatives to existing processes. Performance of a new technology refers to when it
becomes clear that the radical technology provides superior performance characteristics
over the established technology. Market change occurs when the common view of what is
fashionable begins to change, causing current technologies to be challenged. This
generally occurs when the performance limits of a technology are reached requiring the
introduction of a new and radical innovation that is likely to overturn established
technologies. Industry competition occurs when there is competition among members of a
specific industry, causing firms to seek out radical innovations as a means of obtaining a
competitive advantage. Though each of these factors may provide an incentive for change,
it is the combination of several that best explains why most large firms innovate. One thing
Hoed (2007) neglects to mention is governmental intervention and political pressure, such
as the UK Government’s 2011 mandate requiring all public-sector construction companies
to adapt BIM environments before March 2016 (Lecturer and Transportation, 2014). In
these cases incentive comes in the form of potential lost business and reduced profits.
2.3.2 Gartner’s Hype Cycle
When referring to an innovation it is important to understand its maturity and evolution in
the market. Gartner’s Hype Cycle offers a overview of this technology’s transition in the
market, as well as the five stages it must pass through before it becomes commonplace.
As described by O’Leary (2008) and Liden et al. (2003), the hype cycle is intended to
provide a snapshot of the relative maturity of a technology in order to help companies
decide whether it’s a flash in the pan or investment worthy.

26. Literature Review
11
Gartner’s Hype Cycle, as show in Figure 1, is composed of six separate stages, those
being: the technology trigger, peak of inflated expectations, trough of disillusionment,
slope of enlightenment and plateau of productivity. The technology trigger occurs when
there is a breakthrough, product launch or public demonstration that generates significant
press and industry interest (O’Leary, 2008; Linden and Fenn, 2003). The media quickly
begins to discuss the potential impact of this technology on businesses with unrealistic
expectations and over-enthusiasm, leading to the peak of inflated expectations. As
research progresses and case studies are preformed it becomes clear that the technology
does not live up to its overinflated expectations, causing the technology to be rapidly
discredited (O’Leary, 2008; Linden and Fenn, 2003).
Once in this trough of disillusionment, researchers can begin to assess the flaws in their
designs and re-evaluate their processes. This leads to more focused experimentation and
real-world experience, allowing for a better understanding of the technology’s applicability,
risks and benefits (Linden and Fenn, 2003). At this stage, second or third generation
products are released, previous issues with the technology have been solved and market
penetration begins. The plateau of productivity is reached once the technology becomes
mainstream, real-world benefits are demonstrated and accepted without question, and the
technology becomes increasingly embedded into solutions to industry problems (Linden
and Fenn, 2003; O’Leary, 2008). As Linden et al. (2003) explains, the message of the
hype cycle is that enterprises should not invest in a technology just because it is being
‘hyped’, nor should they ignore a technology just because it does not live up to its inflated
expectations.

27. Literature Review
12
Figure 1: Gartner Hype Cycle (O’Leary, 2008).
Given the highly fragmented nature of the construction industry, saturated by small-scale
participants with a low barrier to entry, innovations tend to be incremental. Incremental
Innovations are small improvements in current practices that lead to limited functional
improvements and design variations to components used within existing product
architecture (Marquis, 1988). Referred to as the ‘incumbent curse’, Chandy and Tellis
(1999) describe how an industry like construction tends to avoid radical innovations, even
turning away entrepreneurs and clearly advantageous ideas. The cyclical nature of the
market paired with relatively short timeframes between projects reduces the desire to
invest in research and development. Additionally, there are cultural issues within the
industry including adversarial views, which cause companies to look inwards for
innovations, impeding innovation diffusion. All this paired with the volatility of workload as
a result of the temporal nature of the business discourages radical innovations within
construction industry. Though the barriers seem almost overwhelming, several radical
innovations have found their way into the construction industry.

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2.4 Radical Innovations in the Construction Industry
Innovation is not a word that readily comes to mind when thinking about the construction
industry, though several radical innovations have been adopted over the past 20 years
with varying results. The technologies that apply most to this research are Building
Information Modelling (BIM) and other methods of automation in construction. In these
cases, innovations first met with resistance, but are now consistently regarded as the
future of the AEC industry.
2.4.1 BIM
Computer programmers, Lenid Raiz and Gabor Bojar were the first to introduce BIM to the
construction industry in the form of ArchiCAD in 1984. This 3D modelling program
operated on monochrome screens with 8Mhz. processors, impacting speed, parametric
modelling and the scaling of large projects (Martens and Peter, 2004). Though interest in
this specific technology was not great, the industry understood that this was the future of
architectural design. Further research went into BIM, and by 2000 the programmers
behind ArchiCAD brought a trained architect on board to help develop Revit (Quirk, 2012).
Given direction and guidance from this architect Revit became a revolutionary new
software that created a platform allowing for visual programming using parametric families,
as well as helping to link models with schedules in order to track the process (Goedert et
al., 2008).
Rather than benefiting architects only, contractors and construction managers also saw
the advantage of this technology in the form of quantity take-offs, scheduling and cost
estimations (Goedert et al., 2008). Clients even began demanding BIM models for large-
scale projects such as airports and IT parks in order to guarantee the construction was
sound before even moving to site. As mentioned previously in the definition of BIM, in
2011, the UK Government released a mandate that requires all public-sector construction
companies to adapt BIM environments before March 2016 (Lecturer and Transportation,
2014). Research by McGraw Hill Construction and Young Jr. et al. (2009) make note of
BIM’s rapid rate of adoption, with half of the construction industry dealing with large

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projects using BIM-related tools and a 75% increase in usage between 2007 and 2009.
Some attribute this to the overinflated hype BIM has introduced to the industry, with initial
promises set high in order to attract attention from financial sponsors and to stimulate
interest, both technical and political (Brown and Rappert, 2000; Miettinen and Paavola,
2014). On the other hand, research by Lu et al. (2014) found that when compared with the
non-BIM project, BIM implementation increased the effort input at the design stage by
45.93%, and decreased the cost per square meter by 8.61% in the building stage.
Additionally BIM has been shown to reduce rework and errors associated with CAD/CAM
designing (Young Jr. et al., 2009). Given the overwhelming benefits exhibited by these
processes, pressure from clients and the government, and plenty of successful case
studies, the construction industry has for the most part found it advantageous to adopt this
technology.
2.4.2 Construction Robotics
Through the widening use of BIM in the AEC industry, architects and designers can now
produce data-rich CAD/CAM models. As demonstrated by similar industries such as the
precast sector, explained later in this paper, BIM models are already being exploited in the
manufacturing and automated assembly of prefabricated components. Vähä et al. (2013)
and Nawari (2012) comment on how these CAD/CAM models are able to give specific
component information allowing for the automation of the manufacturing process on or off-
site (Nawari, 2012). Figure 2 below shows how BIM can be used to guide automated and
manual processes through the lifecycle of the project.

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Figure 2: Process Chart for Building Manufacturing using BIM (Vähä et al., n.d.).
The goal behind this technology is the removal of humans from complex, boring and
dangerous industrial production activities (Ding et al., 2014). Researchers Vähä (2013)
and Chu et al. (2013) both comment on how the construction industry has traditionally not
been favourable towards robotic technologies, though issues such as the shrinking labour
population, aging of skilled workers and health and safety issues have pushed for the
adoption of prefabrication and automation. Several attempts have been made since the
1980’s at employing robotics on construction sites, though most of these systems never
made the leap from prototype or research to application (Helm, 2014).
Companies like Shimizu and Kajima developed several types of robotics and automation,
such as single purpose robots and large-scale on-site factory style robotics. Shimizu’s
single purpose robots, such as their wall climbing painting robot and concrete power
floating machine worked faster than human labourers, but required additional time for
transportation and set up, as well as human assistance. As described by Balaguer (2008)

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and Chu et al. (2013) Shimizu and Kajima’s large-scale on-site factory style robots,
namely SMART and AMURAD respectably, utilised full-robotic factories that handled tasks
such as the erection and welding of steel frames, placement of precast concrete floor
panels, and the installation of various prefabricated units. These ‘factories’ would then be
pushed up, controlled by special computer-controlled jacks to continue construction (Chu
et al., 2013). After being introduced to the industry and tested on several buildings, such
as a condominium construction project in Nagoya, Japan it was clear that this technology
still had a long way to go. As Chu et al. explains, the systems only worked on rectangular-
shaped buildings, the entire system took two months to install, required 20 gantry cranes,
exhibited an extremely low productivity in comparison to traditional methods and made it
difficult to meet a financial break-even point. The technology was not advanced enough to
operate in a construction site, which is dynamic, unstructured and unpredictable by nature.
Though this concept of automating the construction industry experienced financial,
technical and cultural barriers, according to Helm (2014), current automated robotics
research is experiencing exponential growth due to rapid advances in hardware
technology and increasingly powerful processors. While the development of a fully
automated system capable of reacting to the unpredictability of a construction site is
extremely challenging, many companies and research teams worldwide are in the process
of developing robots capable of bricklaying, demolition and 3D printing, on and offsite.
Though most of these are still in their research stage and have yet to become mainstream
in the AEC industry, they are proof of the clear trend towards automation and robotics. In
order to get a better idea of this transition from traditional and craft based processes to
automation, parallel industries are investigated to see how they handled this transition and
what types of barriers and benefits they experienced.
2.5 Parallel Industries
This chapter explores sectors similar to the construction industry in order to identify the
challenges, processes and benefits the adaption of automated manufacturing processes
has to offer. The term parallel industries refers to industries such as the automotive and

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manufacturing industries, which also utilize digital CAD design, offsite fabrication, and the
use of CAM automation for the design and fabrication of their products (Gardiner, 2011).
2.5.1 Automotive Industry
The automotive industry is one of the most important economic sectors in the world, with
more than 80% of households in the UK alone owning at least one car (Release, 2013).
With such a large demand and constantly updating technology, the automotive industry
relies on the mass-production of its components through the use of automation systems
and lean manufacturing. These methods allow the automotive industry to stay competitive
by manufacturing new car designs at the lowest cost possible (Gorlach and Wessel, 2008).
While this industry may operate with some of the most advanced technology in the
manufacturing industry to date, it had humble beginnings.
2.5.1.1 Transition from Craft to Digitalisation
Similar to the construction industry, the automobile industry once relied on craft-based
approaches to vehicle design and manufacturing. Master craftsmen led the production
process, assisted by their appetencies. The organization of tasks and procedures in this
process was extremely inefficient and finished products varied widely in quality (Abernathy
and Corcoran, 1983). Quality increased when Henry Ford introduced the first moving
assembly line in 1913, in which the chassis itself moved, reducing bottlenecks and
dependency on highly skilled labourers (Abernathy and Corcoran, 1983).
The advent of the computer brought about a large change to the automotive industry. In
order to keep up with mass production, mass marketing, mass consumption, and the ever-
growing number of suppliers and competitors, interest in the use of computers to facilitate
design and the control of machinery began to develop (Gorlach and Wessel, 2008). IBM
first introduced its software, known as DAC-1 to General Motors in 1965, which assisted in
the design and manufacturing of automobile components (Jonathan and Field, 2000).
Clark (1995) makes note of how, similar to the implementation of BIM and robotics in the
construction industry, the automotive industry initially perceived these new technologies

33. Literature Review
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and production systems as too costly and too large a step away from their current
processes. Though at first the barriers of cost and culture were present, advances in
computer technologies made it possible to achieve economies of scale for mass
production, driving the price down and making the adoption of this technology more
attractive. The automotive and aerospace industries took note of the importance of this
technology, which eventually developed into the interactive CAD/CAM systems used in
these fields today.
The use of CAD/CAM technologies allowed the automotive sector to begin implementing
automated fabrication and assembly systems into their daily processes. Clark (1995) and
Schey (2000) suggest that this step was aided by the use of a system called ‘Computer-
Integrated Manufacturing’ (CIM). Similar to BIM, CIM uses a common database on which
drawings and computer models are stored and shared between multiple parties. If any
changes are made in the design, process, scheduling, bill of materials, quality standard, or
any other system, they are updated throughout the database (Schey, 2000). The following
figure (see Figure 3) shows the hierarchy of this process, covering all aspects of the
process from business management to process control and production. As shown by
Waldner (1992) and described by Clark (1995), the customer’s orders inform the
production plan as to what the end product should be, but it is through the designing of the
CAD/CAM models that the production system is developed. Issues, such as the
sequencing of operations, programming of robotics and optimisation of processes are all
noted and handled in this process.

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Figure 3: CIM Hierarchy (Waldner, 1992).
This step towards automation was a logical next step in an industry focused on high
quality mass-production. By the early to mid 1980’s the ‘workerless factory’ concept was
born, a radical innovation that allowed for full computer control of all aspects of production
(Clark, 1995). This shift in skills required led to the downsizing of the automotive industry,
with large firms like General Motors eliminating over 75,000 jobs in less than 15 years
(Cascio, 1995). As discussed previously, this was a radical step, leading to the
cannibalisation and disruption of all previous processes. As mentioned by Cascio (1995),
Cameron (1993) and Henkoff (1990), this transition had resulted in a loss of morale, trust
and significantly lower productivity in the American automotive industry. Despite the
downsizing and increased automation, productivity only rose 1.2% a year (Cascio, 1995).
Given these statistics it may seem as though automating the industry was far from
beneficial, but Cameron (1993) makes the claim that improper management of this
process is to blame for not reaching the intended cost reductions and productivity. In 1990,
Sakichi Toyoda coined the term “lean management” by which the Toyota company
identified waste and simplified their design processes (Benjaoran and Dawood, 2006).
This involved identifying a balance between automation and manual labour, reducing
complicated processes and replacing them with simpler and more cost effective methods

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(Delkhosh, 2012). Though Cascio (1995) states that his four year study of the automotive
sector revealed very few organisations implementing downsizing in a way that improved
effectiveness, Wormack et al. (1990) and Cameron (1993) point out that Japanese
producers were able to sell the same number of cars as General Motors and 50 percent
more than Ford in 1990 with less than half the workforce. Lean management principles
were later adapted by other major car manufactures, resulting in improved efficiency and a
more organised model of information flow.
2.5.1.2 Increased Automation and its Impact
As mentioned previously, it took some time for automation in the automotive sector to
reach the ‘plateau of productivity’ stage of Gartner’s Hype Cycle. For a while increased
automation brought with it a series of disadvantages, which are described by Clark (1995)
Cascio (1995), and Cameron (1993):
• low work morale
• lower production rates than anticipated
• expensive equipment
• lengthy operator training and even longer durations of system implementation
• large amounts of once-off software required to control the systems
• difficulty integrating devices and equipment from different manufacturers
• difficulty finding system suppliers to provide long-term support
• no indication who was responsible if faults with a particular machine were to bring
the entire production system to a halt
Though the disadvantages to automation were clear, the automotive industry remained
with the technology, investing heavily in research and development until automation
became a standard and the current image everyone has of the industry. Research and
development in this field helped to determine at what level of automation would achieve
high productivity at low costs, consistent quality and flexibility to alter designs. By stressing
lean automation techniques, only the right amount of automation is given to a task,
minimizing overly complicated solutions (Jackson et al., 2011). Given that the cost of
personnel decreases lineally with relation to the number of units produced, and the cost of

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automation increases exponentially as the processes become more complicated, it is
important to find the optimum level of effectiveness (see Figure 4).
Figure 4: Cost Versus Level of Automation (Gorlach and Wessel, 2008).
Once an optimal level of automation was reached the benefits experienced by the
automotive industry were as follows (Granlund, 2011; Clark, 1995):
• increased productivity
• consistent quality
• reduced risk of product failure
• reduced labour costs
• mitigated effects of labour shortages
• improved worker safety
• better quality products
• reduced lead time
• the ability to accomplish processes that cannot be accomplished by other means
• avoiding high costs associated with not automating
• improved market image and credibility with customers
These benefits are not specific to the automotive industry, but rather all parallel industries

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that have instituted automation processes. The shipbuilding industry is another such
example.
2.5.2 Shipbuilding
Similar to the automotive industry, the shipbuilding industry was originally craft based,
traditionally utilising 2D drawings and sketches, only to later adopt CAD/CAM and CIM
processes (Ross and Horvath, 1997; Andritsos and Perez-Prat, 2000), dramatically
improving the quality of their products over the last several decades (Gardiner, 2011). This
transition was aimed at providing solutions to problems associated with the traditional
approach, establishing the most optimised metal handling and treatment processes,
streamlining the whole sequence of operations and assuring shorter lead times between
processes (Andritsos and Perez-Prat, 2000). Just as with the automotive industry, this
adoption of CAD/CAM and CIM processes aided in the transition to automated
manufacturing. Unlike the automotive industry however, as Andritsos (2000) and Perez-
Prat (2000) point out, very few shipbuilding operations are exactly repeatable, with many
operations only performed once or at most a very limited number of times. Given the less
repetitive nature of this industry, robotic manufacturing systems are required to be flexible
in their operations and easily reprogrammable. This transition from a labour intensive to a
technology intensive industry is explained in greater detail below.
2.5.2.1 Transition from Craft to Digitalisation
In the past, the shipbuilding industry operated with a linear orientation towards
construction. Tasks were preformed in a specific order, few trades could begin their work
until the previous trades had finished and tradesmen had to travel through complex
confined spaces one by one in order to access areas for the fit-out (Kieran and Timberlake,
2004). The realisation of these drawbacks led to the use of prefabricated modular blocks,
which could be constructed indoors in a controlled environment. Similar to the precast
construction sector, this led to the improvement of quality, shortening of construction time,
and reduced the number of trades required on site at any given time (Andritsos and Perez-

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23
Prat, 2000; Kieran and Timberlake, 2004). By the late 1970’s, the shipbuilding industry
began investing heavily in computer technology, eventually adopting CAD/CAM and CIM
processes for the modelling of their ships and components (Ross and Horvath, 1997).
Initially the role of these processes was to enhance the various phases of the design
process in order to assure shorter lead times and help with the planning process. As the
technology and complexity of production operations advanced, CAD/CAM and CIM began
being used for the planning and programming of production processes (Andritsos and
Perez-Prat, 2000; Ross and Horvath, 1997). As specified by Andritsos and Perez-Prat
(2000) and Ross and Horvath (1997), manual process handling, marking and welding
were not fully done away with. Similar to the optimisation of automation in the automotive
industry, automation only became evident in repetitive processes, such as the fabricating
of built-up profiles and well-defined welding tasks. As described by Andritsos and Perez-
Prat (2000), there is fierce competition in this rapidly evolving market, with relatively short
timeframes on shipbuilding projects. This has led the EU’s shipbuilding industry to a nearly
50% adoption rate of automated processes, efficiently using steel cutting and laser
welding methods to assure higher quality products.
2.5.2.2 Increased automation and its impact
Similar to the construction industry, the shipbuilding industry is relatively conservative with
its processes, tending towards tried and true methods of the past (Andritsos and Perez-
Prat, 2000). Achieving high levels of automation like the automotive industry is not the
highest priority of shipyards, as ships are generally a ‘one-of-a-type production’ with few
series-production features. On, the other hand, as Ross and Horvath (1997) point out,
automation is still very evident with processes that can be improved by these methods,
such as the fabrication of repetitive components. The reason for this transition comes from
the severe loss of skilled workers, decline in EU shipyards, increasing complexity of
designs and the competitive nature of the industry (Andritsos and Perez-Prat, 2000).
Three case studies preformed by Ross and Horvath (1997) show how the use of
CAD/CAM and BIM technologies, in addition to automated processes of fabrication
allowed these companies to submit lower bids, snare new business and boost market
shares. Automated processes have converted this traditionally craft-based industry into a

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technology intensive sector that is able to stay competitive internationally.
2.5.3 Precast Concrete Industry
The precast concrete industry is investigated in order to provide a comparison to an
industry that exists and operates within AEC manufacturing. By reviewing this industry’s
transition from craft based to automation we can better establish the barriers and benefits
likely to be experienced, as well as understand the main drive towards automation, as it
exists with the offsite manufacturing of concrete components.
Concrete is the world’s most widely used construction material, making up a majority of
the built environment (Spencer, 2011), however with the UK construction industry
continuously finding itself at the centre of criticism and debate for its poor performance, a
new approach was deemed necessary (Nadim and Goulding, 2010). Taylor (2009), Nadim
(2010), Goulding (2012), and Vernikos (2013a) all make note of the UK Government’s
agenda to adopt offsite production methods in order to improve the image of the
construction industry, increase build quality, reach sustainability targets and increase
business efficiency (Vernikos, Nelson, et al., 2013a). As defined earlier, offsite
construction would mitigate the negative aspects of traditional construction such as
temporary structures, vehicle traffic, and health and safety issues. Producing concrete
elements offsite allows these products to be created in a controlled environment where it
can be cured properly, take on more complex shapes, and require less skilled labour, all at
a higher quality than in-situ cast concrete (Jacobson et al., 2011). Limited (2010) and
Lawson (2014) discuss the benefits of the precast concrete process as having been
reported to reduce waste on construction sites by as much as 50% while providing better
budget controls, quicker erection times, and easier management of the construction site.
Though significant research of offsite methods continues to show these benefits, as well
as accompanying global incentives and governmental pressure, Taylor (2009, 2010),
Nadim (2010) and Veriknos (2013b) discuss how many UK contractors are resistant to
adopt these methods. The reason cited is that this process would require the industry to
embrace new ways of thinking and cause a shift in the supply chain and skill sets,

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25
resulting in a transition from traditional craft-based construction to an ‘industrialised’
industry (Nadim and Goulding, 2010). The wide use of BIM in the construction industry is
also lending itself to advancement with offsite processes. Vernikos (2013a), Goulding
(2012) and Nawari (2012) comment on how the use of BIM is likely to increase the usage
of offsite construction in the AEC sector, though Nawari (2012) is quick to point out that
the success of prefabrication offsite using BIM models relies heavily on capturing the
correct content from various stakeholders in the supply chain. Though the utilisation of
offsite operations is still in the process of being accepted as an industry standard, several
innovative companies have been so successful with prefabricating components they have
started automating their own manufacturing process.
Similar to the automotive industry, several companies within the precast concrete sector,
such as Laing O’Rourke, Vollert and Mammut Technocrete have introduced automated
manufacturing technologies into their every day operations. Unlike the mass-produced
elements created in the automotive industry, construction products are both catalogued
and bespoke, requiring each product to be designed and produced to meet the
requirements of their specific project (Cieplik et al., 2010). This uniqueness therefore
requires a more sophisticated approach to the automation and design of these
components (Benjaoran and Dawood, 2006).
2.5.3.1 Transition from Craft to Digitalisation
Alternatives to on-site cast-in-place construction methods became popular around the
1950’s in the UK. With the industry moving towards industrialised forms of building, the
precasting of components became more common (Taylor, 2009). As the overall view of
the construction industry began to deteriorate due to issues with worker health and safety
(Nurminen, 1994), a shortage of labour followed. This shortage of skilled labour as well as
political pressure to move construction offsite resulted in the creation of the precast
concrete industry (Taylor, 2009). Since the early 1990’s, digital design processes have
become commonplace in the AEC industry.

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As the technology continues to advance, computer aided manufacturing technology such
as CAD/CAM and BIM is helping to slowly upgrade the precast methods into a highly
modernised and highly automated process (Galvin et al., 2014). Bock (2007) elaborates
on these manufacturing plants that use multipurpose units, allowing for flexible productions
of concrete floors, walls and roof panels. Through the use of the CAD/CAM models,
controlled concrete distributors are able to spread the correct amount of concrete,
determine window or door openings and place reinforcement as specified. Following the
production of the Egan report, titled Rethinking Construction, where the UK government
identified manufactured construction as a key tenet for improving construction in the 21st
century (Goulding et al., 2012), multiple automated manufacturing plants sprang up
around the UK in order to help feed expected growth in demand for offsite construction
(Morby, 2012). While automation in the precast industry is still uncommon, one company,
Laing O’Rourke, underwent this transition in 2010 with the help of Prihofer Consulting and
automation consultants from the automobile firm, Rolls-Royce (Davies, 2013). This
process removed a good number of workers from the assembly floor and replaced them
with an automated factory, driven by data obtained from CAD/CAM designed components.
This process allowed personnel to review each 3D model prior to fabrication to guarantee
that no important details were ignored, avoiding any loss of time and materials that could
have resulted (Limited, 2010).
2.5.3.2 The Model of Information Flow in the Precast Concrete Industry
Just as with the automotive sector, the precast concrete industry’s workflow and
information flow require a large amount of communication with specialists in the field as
well as those involved with the supply chain (Limited, 2010). The transition from traditional
to digital design methods has removed a substantial amount of time previously spent on
correcting errors, which were not noticeable in 2D renderings. This new process is broken
up into three different stages: design, fabrication and delivery (see Figure 5).

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Figure 5: Process for Automated Precast Concrete Component Fabrication.
Design
The design is first initiated when the customer communicates with the precast concrete
design team pulling together the necessary documents, requirements for the project and
required lead-time (Benjaoran and Dawood, 2006). The precast design team then designs
the modules, using CAD/CAM processes to include all necessary details such as type of
concrete, reinforcement, and any cast in/out elements. As mentioned previously, the use
of BIM technologies would advance this technology even further, embedding metadata
concerning material data and reinforcement in the models themselves. The design
information is then reviewed by the engineer prior to being signed off by the client (Kaner
et al., 2008). Once both teams are happy with the design, the digital information is sent to
the host computer in the factory in order to initiate fabrication (Precast, 2001).
Architecture drawings are recieved
Draftsmen design elements using
CAD/CAM processes
Review by engineer
Design team of client signs off on
design
Digital model is sent to host computer
of the factory
Data is used to fabricate component
complete with reinforcement and cast
in/out elements
Additional work is done by hand by
workers in shop
Concrete is automatically ordered and
batched as per CAD/CAM quantities
Component is cured, logged in the
computer, then delivered to site when it
is required
Design
Fabrication
Delivery

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Fabrication
Flat Panel Type Fabrication
Once received by the shop computer, shop workers assist the automated equipment in the
fabrication of the component. For flat panel type fabrication, data, including the panel
shape, cast in/out elements, and electrical component locations are plotted onto a steel
pallet (Kaner et al., 2008). Shop workers function alongside the machinery to attach the
necessary elements for the fabrication of the bespoke component. This is dissimilar to the
automotive industry in which automation is focused on mass production and therefore
requires less human intervention.
Information received from the CAD/CAM model is then used to determine reinforcement
specifications and placement for the component. Steel is automatically cut, bent, and
welded before it is automatically placed on the pallet. Any additional work not able to be
handled via automation is then fabricated by hand and added manually. Workers then
arrange any extra cast in items into place and test fit the insulation layer later to be
attached to the component. Concrete is automatically batched and deposited onto the
pallet as per the CAD/CAM model, after which the pallet is sent to the temperature
controlled curing chamber under the control of the host computer. This pallet is then
tagged and its information is logged in the system (Precast, 2001).
Complex Geometry Type Fabrication
With non-flat panel type fabrication, the process becomes more difficult. Rather than the
use of flat pallet, special moulds are required which can be time consuming and expensive
to construct. The following are several mould techniques capable of producing complex
geometries such as double-curved façade panels:
1. Reusable Moulds
2. Static Moulds
3. Flexible Moulds

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Reusable moulds are composed of clay or sand and produce no waste material during
their creation, however this method is extremely labour intensive and costly. Static moulds
use an expanded polystyrene (EPS) material, which is formed using CNC routing based
on a CAD/CAM model. This technique is extremely accurate but it produces a good deal of
waste material as this is a subtractive method and each mould can only be used several
times before it must be replaced (Pronk et al., 2009). Lastly, flexible moulds form
themselves to the shape of the required element, either through height-adjustable pistons
or pneumatically charged membranes. This method eliminates the necessity for many
uniquely shaped formworks and allows for the use of an individual formwork which can be
used multiple times and adjusted to the desired shape (Grünewald et al., 2012). This
process is very promising and is still being researched, though current issues with this
method are the cost of investment and the potential for distortion due to piston location
(Pronk et al., 2009).
With current methods available and cost as a driving force, components are generally
redesigned to be as large and repetitive as possible to cut down on the number of moulds
required (Benjaoran and Dawood, 2006). While the use of fewer moulds may result in cost
savings, it also produces a bottleneck in the fabrication process, increasing the component
lead-time due to time spent waiting for mould availability (Pronk et al., 2009). These issues
affect design intent and make low-volume complex geometrical component fabrication
financially infeasible.
Delivery
Once out of the curing chamber, the component is completed with the addition of
insulation and additional panel elements and ready to be delivered to site (Precast, 2001).
At this point the panel is considered to be in its final form and construction ready. Similar
to Ford’s factory stations, the precast sector relies on materials being delivered just-in-time
in order to ensure there is no need for additional storage or lag time on projects (Limited,
2010). Based on the client’s schedule, each building component is then delivered to site
by means of a lorry where it is later installed.

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2.5.3.3 Increased Automation and its Impact
With pressure from the government to enhance the image of the industry, inflated
expectations mentioned in the Egan Report, and a drive from clients to produce better
quality panels quicker and erect them on site faster, many automated offsite
manufacturing factories were established. Companies like Unite Modular Systems (UMS),
Bison and Laing O’Rourke all implemented automated methods in their processes,
investing significant amounts of capital in their own individual ‘fixed-cost factories’ (Morby,
2012). Similar to the automotive sector, initial financial outputs were negative with Morby
(2012) and Gardiner (2013) citing current examples of UMS and Laing O’Rourke not
seeing the volume of work necessary to justify these investments. Gardiner (2013) goes
on to say that Laing O’Rourke has gone so far as to press clients into using prefabrication
solutions, even when it was not in their best interest to do so. Davies (2013) denies this
however, emphasising the need for a large upfront investment to shift the industry into a
place of sustainable processes, higher quality components and shorter timeframes on
projects.
Laing O’Rourke claims that these modern methods of fabrication increase quality
predictability and assurance, faster construction times, less defects, less waste, and better
health and safety for those involved in the construction process (Taylor, 2009; Davies,
2013). Researchers Ding (2014) and Vähä (2013) note however that the development of
construction automation has been slow paced as unlike the automotive sector,
construction projects are bespoke in nature, the technology is not suitable for large scale
applications and the expenses associated with automation make this process unattractive
to an industry where maximising profit is critical. Additionally, as mentioned by Goulding et
al. (2014), the offsite construction industry only accounts for 6% of the total construction
market, though the demand is growing annually.
2.6 3D Concrete Printing
3D printing, or additive manufacturing is defined earlier in this paper as “the process of
joining materials to make objects from 3D model data, usually layer upon layer” (ASTM,
2010), using automated control methods to control the technology. Interest in the

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advancement of construction scale rapid manufacturing techniques has increased
substantially in the past several years according to Colla and Dini (2013) Soar and
Andreen (2012) due to the variety of potential applications of this technology. Castañeda
et al. (2015) focuses on how this method allows for the manufacture of any desired
geometry at a cost that only includes the design time, machine set up, material deposited
and the run time of the machine. The use of concrete as a deposition material opens up a
world of possibilities for the creation of complex bespoke concrete structures that would be
difficult to manufacture in any other way. These processes are aimed at helping to improve
the quality and cost of producing complex components without requiring architects and
designers to scale back their designs (Vollers and Rietbergen, 2007). Researchers such
as Enrico Dini (D-Shape), Ma Yihe, (WinSun), Dr. Behrokh Khoshnevis (Contour Crafting),
and Dr. Simon Austin (3D Concrete Printing) are all investigating methods of the 3D
printing of construction ready products. This research is focused not only on the technical
aspects of the field, but also where this developing technology will find its place in the AEC
industry.
As discussed previously, multiple methods of complex geometric fabrication exist,
including static moulds, adjustable moulds and the additive manufacturing processes. With
the current design intent of architects in the industry, traditional static moulds have been
ruled out due to being too labour intensive and financially infeasible (Benjaoran and
Dawood, 2006). Adjustable moulds provide for the possibility of double curved concrete
panels at a fraction of the cost of traditional moulding technology (Grünewald et al., 2012),
though additive manufacturing provides an alternative to the use of moulding, removing
the need for tooling and allowing for the complete customisation of every individual build
(Castañeda et al., 2015; Buswell et al., 2008). Naboni and Paoletti (2015) as well as
Hauschild and Karzel (2011) and Castañeda et al. (2015) point out the financial benefits of
this process in the long run, though make reference to the high costs of this technology as
well as the reluctant nature of the construction industry with relation to radical innovations.
2.6.1 Comparable Research
Despite the current reluctance from the industry as a whole, several innovative companies
have focused their research and development efforts on the advancement of this
technology. Since 2006, processes such as D-Shape, WinSun, Contour Crafting (CC), and

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3D Concrete Printing (3DCP) have gained significant interest, showing a clear movement
towards the advancement of Large Scale Additive Manufacturing (LSAM) technologies.
The increasing use of digital CAD/CAM modelling and BIM processes have enabled the
ability to create complicated forms that are extremely difficult to conceive, develop and
manufacture (Kolarevic, 2005), producing a drive within the AEC industry to begin
adopting these automated forms of manufacturing (Lim et al., 2012). While the following
additive manufacturing process may differ, they share the same vision of scaling up
additive manufacturing to produce large-scale end use components, whether that be for
art installations, architectural furniture, curved façade panels or construction ready
components.
2.6.1.1 D-Shape
Patented in 2006, Enrico Dini’s process uses an offsite gantry based method, drawing
data from 3D CAD/CAM models and using sand and magnesium oxide mixture to produce
synthetic sandstone components (Dini, 2013). This process works by depositing a binding
agent via a CAM controlled nozzle to a bed of ‘sand’, causing a chemical reaction in the
sand mixture (Lim et al., 2012; Ding et al., 2014).. The gantry holding the printing head is
internally hollow and cyclically filled with the granular material that is deposited and
strained in order to form the next layer (Cesaretti et al., 2014). Due to the nature of this
method, no additional support material is required for overhanging geometries (see Figure
6). This does away with the requirement for the rapid transformation of the catalysed
material to reach a solid state, as everything is supported within the build platform, leading
to a rapid process of fabrication (Gardiner, 2011).

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Figure 6: D-Shape Fabricated Component (Dini, 2013).
Though past work of Enrico Dini’s focused on the fabrication of large scale sculptures,
furniture, and small scale houses, Dini’s present work focuses on the fabrication of an
entire building onsite or the production of modular components offsite (Colla and Dini,
2013; Cesaretti et al., 2014), with an example of a complete house printed in a single
process shown in Figure 7. Additionally, Dini’s research has caught the attention of NASA,
with current research aimed at developing a lunar outpost (Cesaretti et al., 2014; Colla and
Dini, 2013; Lim and Anand, 2014).

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Figure 7: D-Shape Complete House Print (Colla and Dini, 2013).
2.6.1.2 Contour Crafting
Contour Crafting began in 2008 at University of Southern California, with research lead by
Dr. Behrokh Khoshnevis. The process is designed to be crane mounted and installed on
site in order to construct in situ construction scale buildings (Lim et al., 2012). Dr.
Khoshnevis’ reasoning for this process is to decrease waste on site, reduce dependency
on a vanishing workforce and improve on current health and safety standards (Weinstein
and Nawara, 2015). Similar to D-Shape, Contour Crafting is applicable to the construction
of large structures such as houses. Digital CAD/CAM data is used to program the crane-
mounted nozzle, which extrudes a quick setting cement-like material layer-by-layer (R.
Buswell et al., 2005). The nozzle is designed to have one outlet on each side as well as
accompanying trowels for the creation of a smooth wall structure. Additionally, the nozzle
has an outlet on the back for the creation of the inner core (see Figure 8). These nozzles
are static in size and therefore unable to adjust their output resolution, though they can be
deflected in order to create non-orthogonal surfaces (Khoshnevisk, 2004).

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Figure 8: Contour Crafting Nozzle Design (Khoshnevisk, 2004)
Dr. Khoshnevis’s vision for Contour Crafting is focused on the design of low-cost housing
with a goal to capably produce fully customised houses in a single day (Khoshnevisk,
2004). The print speed of this method is relatively quick due to its large diameter extrusion
method. Additionally, Contour Crafting is able to avoid wait time between layers by printing
each layer in two passes rather than one (Lim et al., 2012). While research in this
technology continues to advance, according to Dr. Gardiner, Contour Crafting is currently
only able to produce vertical 2.5D geometries rather than full 3D (Gardiner, 2011). 2.5D
refers to the vertical extrusion of a design, without a distinction between the top and
bottom profile (see Figure 9).

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Figure 9: Contour Crafting created component (Paech, 2014).
Contour Crafting’s inability to produce full 3D elements is due to the current limitations in
the technology. Present methods of producing overhanging geometries require temporary
supporting structures, such as a lintel, to be placed in order to provide geometric freedom
without distortion during fabrication (Lim et al., 2012) . While Enrico Dini’s D-Shape
technology was able to solve this problem, Dr. Khoshnevis is still researching methods
that are cost effective and complimentary to his vision of full building automated
construction. Additional research areas for Contour Crafting are methods for the
integration of reinforcement and the automated addition of electrical and plumbing fixtures
(Gardiner, 2011). Given the current state of this technology, Dr. Gardiner believes there is
still a significant amount of research required before this technology is able to meet
contemporary service and structural requirements (Gardiner, 2011).

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2.6.1.3 WinSun
Yingchuang’s WinSun 3D printing method, developed by CEO, Ma Yihe uses similar
methods to contour crafting, though in a recent interview Dr. Khoshnevis claimed WinSun
was “infringing on his patents, despite the fact they are years behind where (he) is
currently at” with his research (Krassenstein, 2015; Weinstein and Nawara, 2015). Similar
to Dr. Khoshnevis and Enrio Dini’s technology, this process also utilises an offsite gantry
system, however, Yihe is more concerned with the production of simple dwellings at low
costs. WinSun is focused on quantity over quality, using rapid material deposition
techniques and a recycled construction material based mortar (Castañeda et al., 2015).
The process involves a massive extrusion nozzle on a gantry-style machine that extrudes
quick-drying cement in layers in order to create modular components that are later
assembled on site (see Figure 10). This is the primary difference between WinSun and
Contour Crafting, as Contour Crafting’s equipment is designed to be fully assembled on
the construction site. In an interview, Dr. Khoshnevis stated, “compared with prefabricated
construction, 3D printing is not much cheaper, unless it can occur locally, onsite,
eliminating costs of transporting materials and labour” (Castañeda et al., 2015; Ver
Bruggen, 2014). Despite these statements, WinSun is continuing its research into the
rapid fabrication of low-cost housing with Ma Yihe claiming his past projects are proof that
the additive manufacturing technology has increased in scale and its capabilities (Olcayto,
2014).
Figure 10: WinSun Concrete Printed Component (Xinhua, 2014).

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2.6.1.4 3D Concrete Printing
3D Concrete Printing (3DCP) was developed in 2005 at Loughborough University with a
team led by Dr. Richard Buswell and Professor Simon Austin. The process initially
involved an offsite gantry based nozzle and the selective deposition of a mortar style
material composed of 54% and, 36% reactive cementations compounds, and 10% water
by mass (Lim et al., 2012). In its second-generation form, the 3D printer has been fitted to
a robotic arm, which deposits a high-performance concrete precisely under computer
control (Knutt, 2014). The concrete mixture is intentionally viscous in order to increase its
pumpability (ability to be deposited through the nozzle) and stability during the deposition
process. The nozzle design for this method (see Figure 11) includes a single output which
can vary its resolution during the printing process in order to account for the internal bulk
material as well as fine detail (Gardiner, 2011).
Figure 11: 3D Concrete Printing Nozzle Design (Gardiner, 2011)
The ability to selectively deposit material allows for clever design solutions such as
specially designed internal voids, intricate surface textures or the fabrication of complex
geometries (R. a. Buswell et al., 2007). This process also allows for the optimisation of
construction materials, ability to embed mechanical or electrical components within the
wall, and the production of double-curved building panels (R. Buswell et al., 2005). Though

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Contour Crafting has a more rapid extrusion method, 3DCP has solved the issue of
supporting overhanging elements during fabrication. 3DCP uses a secondary material
that is later removed to build upon. This process requires the use of an additional
deposition device as well as additional control instructions (Lim et al., 2012). Given the
design of this technology, with a focus on intricate and selective deposition rather than
extrusion, 3DCP is more focused on the production of bespoke building elements and
complex building panels (see Figure 12), rather than the production of entire structures
(Gardiner, 2011). According to Dr. Buswell, the driving forces of this technology are the
high-end architectural firms who are looking for new manufacturing processes to help
match with their design intent. This technology allows for the low-volume production of
bespoke and non-repetitive components at a much lower cost than other methods (R.
Buswell et al., 2007).
Figure 12: Double-Curved 3D Concrete Printed Wall Panel (Buswell, 2014)
2.6.1.5 Comparison
What all these technologies have in common is the ability to manufacture 3D components
based on digital designs without the requirement of tooling. Tooling and the creation of
moulds is a time consuming and expensive process that puts a freeze on design
(Repository, 2003). Additionally, the first generation models of all of these technologies

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were based off a gantry type system, slicing 3D CAD/CAM models into 2D tool paths,
printing them layer by later. Though all other technologies have remained with this process,
3DCP’s second-generation robotic arm allows for the printing nozzle to remain
perpendicular to the printing surface at all times. Additionally, 3DCPs secondary support
material makes it the only process that is able to fully fabricate complex double curved
cladding panels and other architectural features with concrete. Enrico Dini’s D-Shape
method was the process most similar to 3DCP, with less of a focus on low-cost
sustainable housing like Contour Crafting and WinSun, and more of a focus on high-end
architectural components and panels. Recently, the aim of D-Shape has shifted due to the
research with NASA, tending towards monolithic structures constructed on-site.
Unlike precast methods, where the focus on material finishing occurs on the front end,
rapid manufacturing methods require surface and component finishing on the back end
before they are ready for use. This is an issue in terms of the amount of accuracy and
surface detail attainable with current technologies, but these issues are currently receiving
a great deal of attention and improvements (Repository, 2003). As shown in Gartner’s
Hype Cycle (see Figure 13), recent predictions for macro printing processes are estimated
at more than 10 years in the future (Van Der Meulen and Rivera, 2014). Weinstein and
Nawara (2015) claim the technology itself may have the capability of introducing significant
automation to the construction industry, but its pervasiveness is limited to its adoption.
With the current industry trend towards 3D modelling and CAD/CAM methods, it is
important to understand the model of information flow in the 3DCP process. This will help
bring attention to what changes must be made in order to establish a roll out strategy for
this technology.

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Figure 13: Hype Cycle for 3D Printing, 2014 (Van Der Meulen and Rivera, 2014).
2.6.2 The Model of Information Flow of 3D Concrete Printing
Utilising CAD/CAM methods provides extensive information within each model, including
the mass, surface, and material properties of the structure (Jonathan and Field, 2000).
With the entire AEC industry rapidly moving towards Building Information Modeling (BIM)
processes it is logical to assume that further automation of the construction industry is a
likely outcome. Given the conservative nature of the construction industry and its
attachment to traditional methods, the introduction of an developing technology such as
this would require a new process of construction from the top down. This new process
would have a major impact on the design, data processing, the manufacturing process and
even the cost and business model (Buswell et al., 2008).
With this technology, projects would require a larger amount of planning on the front end
of the project, using BIM style technologies to bring additional professionals and trades
into the design process in order to coordinate the underlying structure and services
required (Jonathan and Field, 2000). This new model of production would therefore

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shorten time to manufacture as the requirement for tooling and mould making would no
longer cause a bottleneck, and time on site would be shortened.
Similar to the design processes of the automotive, shipbuilding and precast sectors, the
3DCP design phase has become much more important. Full CAD/CAM models, including
material qualities and manufacturing information must be completed and checked over by
the proper engineers before they can move along in the process (Ross and Horvath, 1997;
Skibniewski and Wooldridge, 1992). Additionally, components must be reviewed and
updated in order to improve on their constructability during the additive manufacturing
process (Gardiner, 2011). Unlike these two other sectors however, the additive
manufacturing method requires substantial amount of finishing work and post processing
before the components are considered construction ready (Lim et al., 2012).
2.6.3 The Envisaged Benefits of this Technology
The adoption of this additive manufacturing technology has the potential to benefit every
area of the construction industry, such as architecture, engineering, construction, and
health and safety. Similar to the transition from traditional to digital and automated
processes in the automotive, shipbuilding and precast sector, the AEC industry has great
potential to increase its cost savings, output quality, and customer satisfaction. While
these are the most easily identified benefits, many more exist relating to the specifics of
the 3DCP technology.
2.6.3.1 Architecture
Given the current state of manufacturing technology, high-end architects are forced to
scale back their designs, substituting smoothly curved facades or complex low-volume
modular elements with triangulated flat planes (Vollers and Rietbergen, 2007).
Technological advancements have pushed design ability into an area far ahead of current
manufacturing abilities. Traditional techniques of complex module design require tooling
and the construction of moulds, halting the construction phase and creating a bottleneck in
the process. Additive manufacturing processes, such as 3DCP solves that problem by

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allowing for unlimited geometrical freedom at no extra cost (Lim and Anand, 2014; Buswell
et al., 2008). As the only costs associated with this method are the design time, machine
set up, run time and material consumption, the low-volume production of complex
components is much more financially feasible than alternative methods. Below is an
example of a comparison between high-pressure die-cast fabrication, most similar to
mould making in construction, and selective laser sintering, most similar to 3DCP (see
Figure 14). As shown, the SLS method provides a cheaper alternative to the use of die-
cast moulds under a specific volume of production. By focusing on the production of low-
volume bespoke components, this new process stands to move architecture towards a
new era of design, where projects that have never before been possible due to physical or
financial limitations are achievable.
Figure 14: Additive Manufacturing vs. Mould Making (Atzeni and Salmi, 2012).
2.6.3.2 Engineering and Construction
As stated by Dr. Gardiner, this new process of design and manufacturing takes us a step
away from the standard approach of architects designing complex construction projects
and leaving the difficult documentation and design for others to figure out (Gardiner, 2011).
Rather than the use of traditional design approaches, this technology will require a new
process of simultaneous design, such as with the BIM process (Ding et al., 2014; R.

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Buswell et al., 2007). This is especially important with technology like Contour Crafting and
WinSun, where the main focus is on printing entire buildings rather than individual
architectural components. Additive manufacturing and digital design also allows for the
optimisation of the use of materials, reducing components down to their bare essentials as
well as reducing the amount of waste produced during construction (Gardiner, 2011). With
the construction industry producing over 110 million tonnes of waste per year in the UK
alone, there is a clear need for change (Paine and Dhir, 2010).
In addition to the waste created during construction, Mr. Nurminen claimed, in 1994, that
the construction industry was perceived by outsiders as being dirty, difficult and dangerous
(Nurminen, 1994). While the industry has made some changes to rectify this, there still
continues to be a diminishing amount of skilled labour available (Weinstein and Nawara,
2015; Khoshnevis, 2004). This additive manufacturing technology, along with other offsite
manufacturing methods, has the potential to boost the perception of the construction
industry. By producing components offsite, the construction industry is able to remove
more workers from the site while still shortening construction times, provide easier site
management and improve the overall quality of production (Limited, 2010). This would
parallel the benefits experienced by the precast sector, in addition to the accompanying
health and safety benefits.
2.6.3.3 Health and Safety
Given the AEC sector’s comparatively high frequency of accidents as well as premature
retirement and work related illnesses (Bock, 2008), it is clear that a change is needed. As
the UK construction industry has seen a paradigm shift from enforcement-based systems
to safety-culture programmes, ‘Zero Target’ policies have become prominent on most
large construction sites (Sherratt, 2014). The safety issues of the construction industry
may outweigh the cost benefits of remaining with traditional design methods (Sherratt et
al., 2013). Just as with the automotive, shipbuilding and precast industries, the introduction
of automated processes helps to take over the handling of heavy loads, performing of
physical, dirty or dangerous work, and keeps workers from spending extended periods of
time in unfavourable body positions (Bock, 2008). Processes such as precast concrete