Nanotechnology in Construction: A Roadmap
for Development
P.J.M. Bartos1
Abstract. Roadmaps were originally developed as tools for finding surface routes
for getting from one place to another. Recently, the scope of a roadmap has been
extended to cover tools used for indication of pathways for reaching predicted future developments, for assessing progress and indicating trends. This was applied to
developments in application of Nanotechnology within the broad domain of Construction. The Roadmap for Nanotechnology in Construction (RoNaC) was first
developed in 2003 as an aid for forecasting research and investment directions,
with a timescale of 25 years. Five years have elapsed and progress has been
achieved along a few pathways indicated in the original RoNaC. However, construction industry continues to lag behind in both the awareness of the potential and
the expected commercial exploitation of nanotechnology. This paper provides an
updated version based on the three original sectorial charts, indicating where tangible progress has been made, where research is active and where advance along the
predicted pathways has slowed down or stopped altogether.
1 Introduction
The purpose of a Roadmap is to chart trends and developments, which, in this
case, link nanotechnology and construction. It provides a useful tool, a template,
for their predictions. The Roadmap for Nanotechnology in Construction (RoNaC)
has been aimed at facilitating identifications of desirable aims/destinations for
construction RTD over a short-medium timescale (up to 25-years).
The need for development of a Roadmap for Nanotechnology in Construction
th
arose during the 5 FP European project “NANOCONEX” (2002-2003) [1] as one
of its deliverables. It reflected pioneering work exploiting early developments in
application of nanotechnology to construction materials at the Advanced Concrete
and Masonry Centre (1994-) and the attached Scottish Centre for Nanotechnology
in Construction Materials (2000-) at the University of West of Scotland (formerly
P.J.M. Bartos
The Queen’s University of Belfast & University of West of Scotland
e-mail: [email protected]
16
P.J.M. Bartos
the University of Paisley) where the first State of the Art report [2,3] was also
produced. The RoNaC was developed to aid forecasting RTD directions and to inform and guide not only the ‘end-users’ in construction industry but also investors
and national / international bodies supporting research and development. The RoNaC showed the diverse pathways towards nanotechnology-linked expectations,
aims and targets in the very large and economically very significant domain of
construction, envisaged in 2004.
The content of the RoNaC was also linked to work of the RILEM International
Technical Committee TC 197-NCM on Nanotechnology in Construction Materials
(2002-2007). The earliest version of the RoNaC had been presented at the ECORE & ECCREDI conference on “Building for a European Future – Strategies
& Alliances for Construction Innovation”, held in Maastricht in October 2004.
nd
Subsequently it was presented and discussed at the 2 International Symposium
on Nanotechnology in Construction (NICOM2) in Bilbao, in November 2005 and
at the ACI Seminar on Nanotechnology of Concrete: Recent Developments and
Future Perspectives in Denver in November 2006 [4].
Construction industry differs from many other sectors of manufacturing industry in that it adopts and exploits the new nano-scale tools, which have been developed in the more fundamental scientific rather than engineering domain.
Compared to many other industrial sectors, instances where Nanotechnology has
been already successfully exploited and a construction related major product has
already reached open markets still remain few in numbers. Awareness of the potential for exploitation of Nanotechnology in construction has been improving
over the last decade, but expectations of a more practical exploitation have not
been fulfilled, much more remains to be done. Nano-related RTD in construction
has been established in a few sectors; however, it can be still described overall as
an ‘emerging’ trend, often concentrating on new knowledge rather than on an application. Advances are very non-uniform, leading to a particularly pronounced
fragmentation and often to a distinct isolation of current centres of nano-related
construction research and development. These are very important, constructionindustry specific circumstances, accounted for in this RoNaC. Detailed analysis of
nano-related RTD in construction, which was published in the NANOCONEX /
RILEM TC197-NCM State-of-the-Art report [2,3] and which has been updated in
the final report from the TC 197 NCM (publication expected in early 2009) is still
applicable. The report indicated two factors which severely impact on RFTD in
construction inn general and on exploitation of nanotechnology in particular:
(a) An inherently different nature of construction compared with other sectors
of manufacturing industry. Final products of construction, tend to be very complex, non-mass produced and possess a relatively long service lives. This makes
them very different from common products of microelectronics, IT or even aerospace/automotive industries. Construction generally acquires and adapts many inventions from other industries or from related sciences, rather than inventing
them. Construction therefore tends to be much more an exploiter of ideas and inventions than their creator.
Nanotechnology in Construction: A Roadmap for Development
17
(b) Historically very low levels of investment by construction industry into research represent a major hindrance in exploitation of nanotechnology. National
levels of RTD investment in construction are often the lowest amongst all sectors
of the manufacturing industry. This, together with the very high initial capital investment, invariably required in nano-related RTD, combines to generate a major
obstacle for development of an adequate, essential research infrastructure. Overcoming such an obstacle is not helped by the very low margins of profitability
within construction industry and the mid-long term timescale for any commercial
returns to arise from such investments. Recent decline of economic activity worldwide is likely to worsen the situation.
2 Routes and Pathways
The ‘quality’ and usefulness of existing and new, developing, roads and pathways
for progress reflect the availability and ‘quality’ of relevant supporting infrastructure. The infrastructure has to be upgraded with passage of time if it were to fulfill
its role in supporting research, development and practical exploitation of nanotechnology. The rate of advance towards highly desirable medium-long term goals
would slow down, perhaps even stop entirely, if the necessary infrastructures were
not adequately maintained and periodically improved. Nanotechnology related research infrastructures, which ‘pave the way’ include:
• Instrumentation and associated methodologies for nano-scale investigations.
(characterisation of properties at nano-scale, nano-assembly and nanofabrication, analytical techniques and imaging at molecular /atomic scale).
• Descriptive, preferably also genuinely predictive, numerical models, which include a linkage across the whole scale, from nano-to-macro size.
• Standardisation of basic nano-scale metrology equipment and provision of
means for an assessment of their performance. Development of new, more effective tools for a meaningful nano-scale characterisation of materials.
Instrumentation and metrology at nano-scale are developing at a very fast pace,
which inevitably brings with it a rapid rate of obsolescence. The rate of obsolescence is comparable to that seen in the IST area, however ‘hardware’ costs of
nano-scale instrumentation and costs of its maintenance / calibration / upgrading,
even if only on a moderate scale, are higher than for IST research.
It is impracticable to produce one, all-encompassing, single map for the whole
of construction in which all the existing and potential routes and /pathways of progress linked with nanotechnology would be shown. A single comprehensive map
would include a multitude of ‘pathways’, criss-crossing each other. To show them
all in one chart/roadmap, with all the numerous possible intersections, interactions
and feedbacks would lead to a tangled mass of connections resulting in an illegible
and incomprehensible document.
A solution has been found in the creation of a number of simpler charts in
which the nano-related construction research pathways and / routes, heading
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P.J.M. Bartos
towards specific ‘destinations’, have been clustered. An example is the Chart 2:
‘Buildings of Future’, where the overall destination has been defined by a number
of highly desirable goals/ and outcomes, presented in the chart.
Some of the pathways shown may appear in another chart(s). This is to be expected, as Nanotechnology is fundamentally an ‘enabling technology’, where one
advance, especially when it is a major advance, is very likely to underpin progress
towards desirable goals in more sectors than the original one. Simplicity and
‘legibility’ of a chart restricted the scope for presentation. It was not practicable to
indicate the current status of the routes/pathways, e.g. showing which roads were
‘under construction’ or just ‘planned’. Activities shown in the specimen charts
have colour coding to indicate Existing pathways are shown in red. Many ‘connections’ are seen today as relatively ‘thin’, faint and indistinct routes, which is
how they are perceived today, but which, in future, may (or may not!) become
well-established, densely ‘trafficked’ wide principal routes / highways enabling a
much faster progress towards the future goals indicated within the ‘destination’.
3 Benchmarks and Timescale
Information and data from the State-of-the-Art report [2] helped to establish the
benchmarks for the development of the RoNaC. The original survey had been to
support European projects and gave priority to Europe. However this was extended
to include an analysis of existing knowledge, proposed and current nano-related
R&D activities applicable to any part of the construction sector on a global scale.
st
Contributions presented at the 1 International Symposium on Nanotechnology in
Construction, Paisley, UK, June 2003 [5], active links with the TC-197 NCM on
Nanotechnology in Construction Materials, established under the auspices of
RILEM in 2002, and events organised and documents produced by the UK Institute
of Nanotechnology [6] and other organisations were reviewed and their conclusions
nd
considered. The 2 International Symposium on Nanotechnology in Construction
(NICON2) in Bilbao, Spain in November 2005 confirmed the emerging trends and
indicated several new projects exploiting nanotechnology [7].
The RoNaC charts were plotted against a timescale, which provided a measure
of how distant the required or desirable research and development destinations
were from a ‘benchmark’ situation in 2004, its starting point. The timescale extends to 25+ years ahead, with the first five years already covered. It is important
to note that the greater is the extension of the time interval into future, the greater
are the potential errors and the lesser is the reliability of forecasts in this rapidly
and unevenly developing field.
There are three ‘specimen’ Charts shown. Sufficient information is already
available from individual publications and reviews [1–4,7] and from the final
documentation from the RILEM TC 197 NCM [8] and other sources, to enable
production of new charts in a similar format. It is possible to re-define the baselines and destinations and focus on different aspects linked to nanotechnology.
Nanotechnology in Construction: A Roadmap for Development
19
It is important to appreciate that the ‘routes/pathways’ shown in the charts are
in many instances only now being formed or traced. Additional ones may develop
in due course, and may not even exist as yet.
4 Vehicles, Drivers
The choice and understanding of the research ‘vehicles’ needed to pursue specific
goals and the capability of their ‘drivers’ to steer them along correct routes to desired outcomes and destinations, always require adequate prior knowledge of both
Nanotechnology and the relevant sector(s) of construction industry. Inadequate
knowledge, or its absence mean that not all of the pathways/routes (if any), including their intersections, as shown on the attached Charts, may be clear and recognisable to potential developers and exploiters – and any advance may be slow,
sometimes taking wrong paths leading to ‘dead-ends’ (and wasted resources). If
knowledge represented the ‘vehicle’, then the ‘drivers’, which represent the motivation to go ahead, can be also identified.
The greatest impact on the construction industry and the economy within the
timescale of the Roadmap is expected to come from an enhancement in performance of materials – a very strong driver of construction RTD. This, in turn, is
likely to arise from an improved understanding and control of their internal structure on micro-to-nano-scale and from a potential improvement of their production
processes. The eventual total impact in construction will be almost always very
substantial, due not necessarily to radical technological leaps forward but mainly
to massive quantities in which basic (‘bulk’) construction materials are used.
Most of the advances along the specific research routes and pathways of RTD
are predicted to be incremental, leading to a relatively steady progress related to
existing, namely the ‘bulk’ materials and technologies. Such a relatively steady
progress will be strongly influenced by developments in the research ‘infrastructure’ It may be that some of the expected improvements will not take place and
there will be a waiting period with only a small or even zero advances, until a
breakthrough occurs and the physical capability of the equipment (infrastructure)
is instantly and significantly upgraded or there is a significant advance in interpretation/understanding of data/results obtained.
An improved understanding of structure-properties relationships and an ability
to control the structure of many materials on the nano-scale is expected to provide
the greatest opportunities for major advances in construction materials science.
Such breakthroughs will enable the ‘materials by design’ approach to replace the
traditional one of a ‘trial and error’, enabling properties of a material to be tailored
for optimum performance in a specific application.
Additional, often mutually complementary drivers are market pull, venture
capital involvement, competitiveness and prospects of higher financial returns.
Their significance can vary, depending on the availability of the basic ‘vehicle’ –
presence of an adequate knowledge & information.
20
P.J.M. Bartos
5 Business Environment
Construction industry is a very substantial contributor to economic performance.
In Europe alone, its annual turnover is estimated [9] at about 1000 billion Euro. At
the same time, it is estimated that 97% of employees working within it are
employed by enterprises with less than 10 staff. The Small and Medium size Enterprises in construction are generally not involved in RTD activities and acquisition of the required minimum knowledge, and awareness of opportunities brought
by nanotechnology, is difficult. At present, such knowledge still appears to be inadequate if not entirely absent. The ‘vehicle’ for advance along the existing and
potential pathways is therefore available only to large companies, as is confirmed
by the appearance of the first practical, commercial, nano-related products on the
market.
The way ahead - an exploitation of the directions such as those shown in the
specimen RoNaC charts is proving not to be easy and straightforward because the
knowledge required at different levels of construction-related staff still tends to
lag behind the continuing advances in nanotechnology achieved elsewhere.
It is possible to conclude that in the absence of an environment conducive to
acquisition of an adequate knowledge through education and training, many of the
basic and most significant drivers of progress, such as market pull, venture capital
involvement, competitiveness and prospects of higher financial returns, will be either weak or will not be established. Numbers of skilled research related personnel
at both the scientific/supervisory level and at the supporting staff/technician level,
who possess the required combination of knowledge related to construction and
nanotechnology, continue to appear to be too low to provide the manpower required to steer and move efficiently forward the ‘vehicles’ for expansion of nanorelated RTD in construction and development of marketable products.
Countries leading the development and exploitation of Nanotechnology, such
as the USA, Japan and European Union [8,9], appreciated the necessity of providing major financial support from state/government sources The US government set
up the National Nanotechnology Initiative in yr. 2000, which has committed an
initial funding of more that one 700 million US$ of public funds to facilitate the
additional commitment of private venture capital for specific developments
through its different agencies [8]. As has been noted in the first RoNaC, all but a
very small fraction of the public funding for nano-related RTD was channeled either into non-construction industries or into development of general nano-scale research infrastructure, which was then used primarily to support non-construction
research, perceived to be more ‘high-tech’.
Investment into research infrastructure can benefit construction and it can
‘smooth/pave’ some of the development paths shown in the Charts. However, this
would require a significant change in management of such facilities, to enable a
few construction-related ‘vehicles’ to squeeze into the densely trafficked RTD
pathways, already crowded by nano-science related vehicles with no connection to
Nanotechnology in Construction: A Roadmap for Development
21
construction. Unless there is such change, benefits to construction from such
nanotechnology related infrastructure investments are likely to be disproportionately low compared with the economic significance of construction, which, in EU
contributes approximately 10% of GDP. Other significant drivers are emerging,
and are likely to gain significance in terms of construction and nanotechnology.
These include climate change and the associated issues, both on a global scale and
in local urban redevelopment.
6 Roadmap and Charts
An overall roadmap covering the whole of construction would be so complicated
to make it difficult to understand. The ‘scale’ would have to be adjusted to make it
‘legible’, but then the roadmap would become too ‘coarse’ to make it useful. As a
result, such a roadmap would not reveal adequately details necessary for an appreciation and understanding of the links, relationships and dependencies of varied
significance, which may exist between the pathways shown.
Instead of a single roadmap, a ‘complete’ RoNaC would therefore become a
‘road-atlas’ comprising a collection of ‘sectorial’ charts such as the examples attached. Each chart would be focused on a coherent cluster of aims and destinations, depending on the purpose of each chart.
Aims and destinations, which are expected to be of significance for construction in the medium-long term include:
• Understanding basic phenomena (interactions, processes) at nanoscale: e.g.
cement hydration and formation of nanostructures, origins of adhesion and
bond, pore structure and interfaces in concrete, mechanisms of degradation,
relevant modelling and simulation etc.
• Bulk ‘traditional’ construction materials with a modified nano-structure: e.g.
concrete, bitumen, plastics modified with nanoparticulate additives, special
admixtures and new processing techniques modifying internal nanostructures
etc.
• New high performance structural materials: e.g. carbon nanotubes, new fibre
reinforcements, nanocomposites, advanced steels and concrete/cement composites, biomimetic materials, etc. Materials with extended durability in extreme
service conditions.
• High performance new coatings, paints and thin films: e.g. wear-resistant coating, durable paints, self-cleaning/anti-bacteria and anti-graffiti coatings, smart
thin films, etc.
• New multi-functional materials and components: e.g. aerogel based insulating
materials, efficient filters/membranes and catalysts,, self-sensing/healing materials, etc.
• New production techniques, tools and controls: e.g. more energy efficient and
environmental friendly production of materials and structures, novel processes
with more intelligent and integrated control systems, etc.
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P.J.M. Bartos
• Intelligent structures and use of micro/nano sensors: e.g. nano-electromechanical
systems, biomimetic sensors, paint-on sensors, and self-activating structures/
components, etc.
• Integrated monitoring and diagnostic systems: e.g. for monitoring structure defects and reinforcement corrosion, environmental changes/conditions, and detecting security risks, etc.
• Energy saving lighting, fuel cells and communication devices: e.g. efficient and
cheap fuel cells and photovoltaics, photocatalytic materials etc.
The Charts provided as examples show pathways emerge from a baseline to the
left of the Chart. If appropriate, the baseline can be split into separate ‘blocks’, indicating different sub-areas of research. Each sub-area may consist of several recognised and related ‘research streams/directions.
Progress forecast along each of the identified nano-related RTD activity paths
is shown against a linear timescale from 0 to 25 (+) years. Activities, which are
shown starting within the first five years, are already being pursued or about to
commence. Aims/destinations, common to each of the charts, are shown on the
right hand side and basic characteristics/parameters of the aims are also listed
there.
A simple elongated rectangular box represents each research activity. However,
this does not indicate a very precise and sudden start and finish, and a uniform
intensity of the activity throughout its expected duration. It is s a simplification,
which has been adopted for the sake of clarity, and because it is impossible to predict variations in the intensity/magnitude of research which are inevitable during
each of the activities. There may be ups and downs, and even breaks / discontinuities, when funding may drop below the level required to sustain advance. Unexpected and at that time perhaps temporarily insuperable technological problems
may be encountered on the path followed, or even an unexpected dead end may be
encountered, for example by discovery of a hitherto unknown ecological or health
& safety threat or danger. Each ‘activity box’ is therefore presented in a simplified
linear and parallel direction, with only major interactions indicated as ‘diagonal’
connecting lines. As mentioned before, some of the activities will be using common paths/routes and share the infrastructure. Many overall ‘integrating’ aspects
therefore arise because of the commonality of some of the nano-scale approaches.
This is a feature representing the inherent multi-disciplinarity of RTD, which exploits advances in nanotechnology.
A general activity, which is beginning to be more appreciated, and which can
be associated with any of the specific (‘boxed’) activities shown is an evaluation
of health and safety, both during the process of research and development and
regarding practical products / applications. It is now very urgent to provide an
adequate national and international legislative cover and avoid potential health &
safety problems undermining confidence in nanotechnology in general.
Nanotechnology in Construction: A Roadmap for Development
23
7 Specimen Charts
Original charts are provided; year 2009 equates to year 5 of the timescales shown.
7.1 Chart 1: Traditional Bulk Construction Materials
TIMESCALE (years)
Present
0
5
10
20
25+
Destination
novel, non-traditional binders
ductile cements & tougher concrete
nano-layers/coatings
Ceramics,
bricks, glass
bio-active surfaces
tougher ceramics
self-cleaning glass
Bitumens,
polymers
nanofillers
molecular assembly of new polymers
Timber
modified wood for construction, fast growing defect-free, dense/strong
Advanced Bulk Materials
Concrete
low energy cement
Negligible / zero / positive environmental impact, sustainable
resources, pre-set grading of properties replaced by properties
optimised for applications
Steel
corrosion resistant construction steel
NANOCONEX ROADMAP: Chart 1 - Bulk Construction Materials
Chart 1 reviews potential for exploitation of nanotechnology where even incremental improvements are likely to lead to big commercial and environmental /
societal gains because of the extremely high ‘multiplying factors’ attached to such
materials. Activities shown follow generally the ‘top-down’ approach, in which an
existing material is improved through knowledge and modifications carried out
down at the micro-nano level.
Timescale of 5 years have been reached in 2009, with progress in knowledge being achieved in most of the activities but with products appearing only in the areas
of steel (very limited) and ceramics (photocatalytic coatings, selfcleaning glass).
Concrete coatings have only moved if the photocatalytic surfaces are concerned.
7.2 Chart 2: Buildings of Future
The chart outlines the potential for exploitation nanotechnology leading to a much
higher standard and much more environmentally acceptable, and eventually fully
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P.J.M. Bartos
TIMESCALE (years)
Present
0
5
10
20
25+
Destination
Active nano-coatings
self-cleaning glass and bio-active surfaces
BUILDINGS of TODAY
High performance insulating materials
High thermal mass materials
Stronger, tougher, lighter and more durable composites
Smart materials and components
Safety and security
Fibre-optic and microchip control systems
Photovoltaic surfaces & solar cells – roofs & cladding
Buildings of Future
Zero or positive energy balance; maximum sustainability
of resources; integrated lifespan of materials and components;
minimum maintenance; healthy environment; recyclable materials
& components
Embedded sensors, condition monitoring and diagnostic devices
NANOCONEX ROADMAP: Chart 2 – Buildings of Future
sustainable, building construction. Achievements/destinations reached by routes
shown in Charts 1 and 3 will be associated with or support activities shown in this
Chart.
TIMESCALE (years)
Present
0
5
10
20
25+
Composites with self-adjusting interfaces
Smart materials, shape memory, self-repairing, strain hardening
Active nano-coatings
Novel, controlled and durable fracture mechanisms
Stronger, tougher, lighter and more durable composites
Exploitation of nanoparticles, nanotubes, nanofibres
Photovoltaic materials
Safety and security
NANOCONEX ROADMAP: Chart 3 – NOVEL MATERIALS
Novel construction materials
EXISTING CONSTRUCTION MATERIALS
Bio-mimetic materials
Construction materials ‘built’ from basic nano-scale basic
components. Extreme strength and toughness; no health hazard;
acceptable degree of sustainability of resources, environmentally
harmless on local/global scale
Unforeseen developments?
Destination
Nanotechnology in Construction: A Roadmap for Development
25
7.3 Chart 3: Novel Construction Materials
The chart follows primarily the ‘bottom-up’ development process, where materials
of substantially altered properties and a much high performance are ‘built’ or ‘assembled’ from the basic nano-scale constituents (molecular – atomic level).
It is most important to note the ‘unforeseen developments’, an activity box that
covers developments not even thought of at present.
8 Conclusions
1. Since the first issue of the RoNaC in 2004, the exploitation of the RTD potential in construction through nanotechnology in construction remains in an ‘emerging, / early development’ stage.
2. The RoNaC presented includes three specimen charts covering the most common ‘clusters’ of construction research activities, where nano-based research and
development activities are already carried out and several routes/pathways are already established. Additional charts can be developed for specific activities or
aims/destinations.
3. The uneven progress of exploitation of nanotechnology in construction and the
specific nature of the construction industry limit the accuracy of the forecasts
shown in the RoNaC. Reliability of predictions regarding commencement, duration and end of activity also decreases rapidly as the commencement time becomes more distant from present (year 5 from original time zero).
4. Integration of the currently fragmented nano-related research in construction
and the use of common ‘vehicles’ at national or international levels would considerably speed up progress along the pathways outlined in the RoNaC.
5. Most of the overall construction output is through Small and Medium Enterprises. The SMEs in construction domain have negligible research and development capabilities. They cannot be therefore considered as effective vehicles for
progress in exploitation of nanotechnology in construction, although they need to
be associated with the RTD and their awareness of developments should be improved.
6. Activities concerned with monitoring and evaluation of ecological, environmental and health & safety aspects of materials and processes both during research at nanoscale and for development of marketable products are expected to
become an essential part of all activities considered.
7. The RoNaC charts provide a ‘snapshot’ of the current situation in only three
sub-sectors of construction, after five years from its first publication. It is suggested that similar ‘templates’ are used to develop further charts focused on different sub-sectors or topics, and the charts are updated every 3-5 years.
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P.J.M. Bartos
Acknowledgments. The author wishes to acknowledge the assistance provided by partners
in the FP5 “Nanoconex” European Project and to thank colleagues in the RILEM Committee TC197 NCM “Nanotechnology in Construction Materials” for their collaboration.
References
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Labein, Bilbao, Spain (2003)
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