22-01-2013, 12:52 PM
Significance of Nanotechnology in Construction Engineering
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Abstract
Nanotechnology is one of the most active
research areas that encompass a number of disciplines
including civil engineering and construction materials.
Traditionally, nanotechnology has been concerned with
developments in the fields of microelectronics, medicine and
materials sciences. However, the potential for application of
many of the developments in the nanotechnology field in the
area of construction engineering is growing. In this paper a
broad overview of the potential application of various
nanotechnology developments in the construction
engineering field is discussed, and the potential for further
basic research that may lead to improved systems is
evaluated.
INTRODUCTION
Nanotechnology is a field that is dominated by
developments in basic physics and chemistry research
[1], where phenomena on atomic and molecular level are
used to provide materials and structures that perform
tasks that are not possible using the materials in their
typical macroscopic form. The evolution of technology
and instrumentation as well as its related scientific areas
such as physics and chemistry are making the research on
nanotechnology aggressive and evolutional [2]. Not
surprisingly, it is observed that expenditure on
nanotechnology research is significant. The U.S. National
Nanotechnology Initiative (NNI) expenditures exceed $1
billion each year, with the President’s 2008 budget for
NNI at $1.5 billion. However, the research is mainly
moving forward motivated by immediate profitable return
generated by high value commercial products [3]. It has
been established by study, nanotechnology in
construction ranked 8 of 10 applications that most likely
have impact in the developing world [4].
APPLICATION OF NANOTECHNOLOGY IN
CONSTRUCTION
Nanotechnology can be used for design and construction
processes in many areas since nanotechnology generated
products have many unique characteristics. These include
products that are for: Lighter structure; Stronger
structural composites e.g. for briges etc ; Low
maintenance coating ; Improving pipe joining materials
and techniques ; Better properties of cementitious
materials ; Reducing the thermal transfer rate of fire
retardant and insulation ; Increasing the sound absorption
of acoustic absorber ; Increasing the reflectivity of glass.
There are large numbers of applications of
nanotechnology in construction engineering/industry.
Some of these applications are examined in detail below.
Concrete
Concrete is one of the most common and widely used
construction materials. The rapid development of new
experimental techniques makes it possible to study the
properties of cementitious materials at micro/nano-scale.
Research has been conducted to study the hydration
process, alkali-silicate reaction (ASR), and fly ash
reactivity using nanotechnology [6]. The better
understanding of the structure and behavior of concrete at
micro/nano-scale could help to improve concrete
properties and prevent the illness, such as ASR.
Nanosensors
Nano and microelectrical mechanical systems (MEMS)
sensors have been developed and used in construction to
monitor and/or control the environment condition and the
materials/structure performance. One advantage of these
sensors is their dimension (10-9m to 10-5m) [11]. These
sensors could be embedded into the structure during the
construction process. Smart aggregate, a low cost
piezoceramic-based multi-functional device, has been
applied to monitor early age concrete properties such as
moisture, temperature, relative humidity and early age
strength development [12]. The sensors can also be used
to monitor concrete corrosion and cracking.
The smart aggregate can also be used for structure
health monitoring. The disclosed system can monitor
internal stresses, cracks and other physical forces in the
structures during the structures' life. It is capable of
providing an early indication of the health of the structure
before a failure of the structure can occur.
FUTURE CHALLENGE AND DIRECTION
As with most developing technologies, a major number of
challenges exist during the initiation of the application of
the technology into reality. It is important to be realistic
and identify and plan for the limitations and challenges
inherent in this process. In this section a short summary
of selected challenges and limitations affecting
application of nanotechnology in construction
engineering are provided. The following main challenges
and limitations can be defined: Fabrication, Health,
Environment and Cost
Fabrication
Current efforts in the field of nanotechnology are focused
on the fabrication, characterization and use of these
materials on a nanoscale domain. This leads to most of
the development work focusing on very small quantities
of material that is typically far removed from the type of
quantities required for typical construction infrastructure.
One of the potential solutions to this is to focus on the
nano materials to act as catalyser, thereby reducing the
amount of nano material required substantially. Another
viewpoint is that for many applications, the material does
not necessarily have to be used on a nano scale to obtain
a major improvement in benefits. This would be the case
with reduction of the dimensions of cement, where a
substantial improvement in strength can already be
obtained through the large scale milling of the cement to
a finer form than the traditional form. Although the
cement may not be purely a nano material as yet, the
benefits obtained would already be substantial [13].
CONCLUSIONS
Based on the information discussed in this paper, the
following conclusions are drawn:
• Nanotechnology is a rapidly expanding area of
research where novel properties of materials
manufactured on the nanoscale can be utilized for the
benefit of construction infrastructure
• A number of promising developments exist that can
potentially change the service life and life-cycle cost
of construction infrastructure.