Nanotechnology

The innovation of nanotechnology has the prospective of transforming civil engineering because it helps create materials with unique functions and properties. Nanotechnology is the control and manipulation of matter, particularly atoms and molecules ranging from 10-9m. Analysis on the malleable structural compounds and their outstanding properties like low preservation coatings, good materials of cementitious products, the reduction of thermal transfer of fire in insulation and retardancy, nanosensors, and intelligent composite technology. The main features analysed are self-monitoring, rehabilitation, cleaning and self-healing techniques, which can be incorporated into the health system, thus bridging the gap between construction and nanotechnology. Nanotechnology has been used in construction since the early 1990s and its importance has become apparent in constructions in the UK, where nanotechnology has been used in mixing concrete products. The technology received a huge boost from the funding by the European Commission (Yun & Min 2011, p. 11).

Nanotechnology can be used in different ways by civil engineers and one of its applications is in the design and construction because it creates products with unique characteristics. The unique characteristics of nanotechnology products help the civil engineers fix many construction problems. The use of nanotechnology in the study of concrete properties, like its reaction to hydration, the alkali silicate reaction (ASR) reaction caused by reactive aggregates of silica and the alkali content of the cement and the fly ash reactivity. Fly ash helps in improving the durability of the concrete and reduces the amount of cement required to make concrete. The problem with fly ash is it slows down the curing process and compromises the strength of concrete at the initial stages of concrete curing. Nano-silica application to concrete improves the mechanical properties of the concrete by countering the effects of fly ash and improving the density and strength of the concrete. Nano-silica also helps improve the resistance of concrete. Carbon nanotube addition into the concrete helps increase its weight and strength by improving the mechanical properties of Portland cement. The other use of nanotechnology in concrete is its use in crack repairs where a self-healing polymer is released into the crack and initiates catalysis and polymerization to bond the cracks. A fibre sheet with nano-silica particles that harden and increases the strength of concrete is now commonly used to wrap concrete (Wang 2009, p.43).

The other application of nanotechnology is in structural composites where nanoparticles are used to incorporate copper to reduce corrosion of steel. This is common in bridges where low carbon steel was used by the U.S. Navy. The Sandvik Nanoflex is a steel, which is resistant to corrosion, lightweight, and is wear and tear resistant. The steel has superior properties that strengthens it makes it ductile and resistant to fatigue. The steel material has a longer life, especially in environments of high corrosions and low construction costs. The Carbon nanotube is over a hundred times stronger than the steel and is light. It also has a high conduction rate and is highly flexible preventing it from breaking unlike the carbon fibres (Walus, Dysart, Jullien, & Budiman 2004, p. 145).

Nanotechnology is also applied in coatings where nanoparticles are used to protect coatings from corrosions. The coatings come in different forms like self-cleaning, thermal control coats, anti-reflection coatings, and antibacterial coatings. The coatings operate in two independent procedures, with the first one applying photo catalytic nanosized TiO2 molecules, which reacts with UV rays to break down dirt in windows, a technology applied in self-cleaning (Fuchs 2009, p. 78). The second process uses the hydrophilic components of the coating where it spreads rainwater evenly over the surface to wash the dirt broken down in the first process. The lotus spray technique is used to retain its effects after contact with an abrasive or sandpapers. Nanostructured coatings are also used to reflect light on surfaces using different wavelengths and transmit it. The use of light responsive materials in buildings can help minimize the use of energy in buildings by responding to colour changes and temperature (Nakamura 2007).

The nanotechnology application in the fire-protective glass is achieved through the application of an intumescent layer placed in between glass from silica (SiO2) nanoparticles. SiO2 nanoparticles become rigid when heated creating a shield that can prevent fires. There are nanotechnology sensors, which create materials with a high sensing power. During construction, nanosensors are embedded into the building and help monitor changes in environmental conditions. Nanoporous silica is used in making insulating materials because of its low density and small size. The use of photovoltaic fuel cells in buildings will help the constructors to build sustainable projects, save energy, and avert environmental degradation. This could be achieved through the development of plastic solar cells to replace the LED lamps. The plastic solar cells are relatively cheap to produce (Hu, Sarveswaran, Lieberman, & Bernstein 2005, p. 92).

The impacts of nanotechnology on construction fields are many and the most outstanding one is the reduction in construction and maintenance costs. The constructions have a longer lifetime because of the reduced corrosion of the materials used (Cho, Yun, Kim & Choi 2011).

The use of nanotechnology is not yet widely spread because it is still at its initial stages of research. The products in the market are not put into use because they are not well marketed. The research on the impact and application of nanotechnology in the construction fields should be further explored to make sure constructions last longer. The cost of constructions can also decline with the use of nanotechnology in the field. This means that more efforts and resources need to be put in to support the various uses of nanotechnology in civil engineering.