Nano-steel, smart buildings and self-healing concrete - welcome to the future of the construction industry.

Just how enormous is the global construction industry? The answer can be measured in lumps of concrete. Every year, for every person in the world, one metre cubed of concrete is produced. The industry is, unsurprisingly, one of the major consumers of energy, and consequently, a significant contributor to global warming. And given the huge amount of fixed assets dedicated to designing, constructing and maintaining in the same tried and trusted fashion, there is considerable inertia to change.

Even nanotechnology, a potential prime driver of change in all industries, is coming up against this brick wall. Yet, slowly but surely, it is beginning to have an influence and will potentially, in the near future, go on to revolutionise the whole construction process.

Beginning at the foundations, there is great interest in improving the properties of concrete. Several studies are taking place involving the introduction of carbon nanotubes (CNTs) as fibre reinforcing. Steel, with its reliance on carbon as an alloying element, is an obvious candidate for the introduction of CNTs, and work on using CNTs to create high strength, high toughness steels is an on-going area of research.

Other groups are going further, by exploring the possibility of self-healing concrete” using embedded Nan capsules of sealant, which break open and fill any cracks in the concrete surface as they occur. Still further research involves the use of so called “smart aggregate”, where MEMS-based (microelectromechanical) sensors are cast into the bulk concrete material, feeding back information on the state of the structure. If embedded in roadways, these same sensors might even extend to 

monitoring traffic movement. Even the timber industry stands to benefit from nano enhancement. Research has shown that the cellulose nano-fibrils that compose timber re astonishingly, 25% as strong as CNTs, but have the potential to be much cheaper to produce, and the benefit of being completely natural. Construction materials made of “harvested” nano-fibrils, without the defects associated with natural timber, could produce remarkable changes in the construction market, for homes (the traditional major user of construction timber), commercial buildings and other structures. Further research is being directed towards making timber materials that are super-insulating and even photovoltaic. In this way, buildings would not only be made from a renewable resource (wood), but also act as a collector of renewable solar energy.

The use of so-called “nano-dust” (nanosized detection systems) is an exciting prospect bother for the monitoring of civil works. The concept of building-wide monitoring of heat, light and air quality opens up a prospect of much more efficient allocation of resources, which is becoming increasingly important as we strive to conserve energy.

Finally, for the finishing touch, super-insulating paint, based on nanotechnology, is already being used to reduce the energy requirement of a building. Another project is to create paints that would change colour to suit the owner’s preference. There is even the possibility of using innovative photovoltaic “glass” in façade design, which will open up further new avenues for sustainable architecture.

Despite its natural inclination to be a laggard in the adoption of advanced technology, the construction industry could eb one of the biggest beneficiaries of Nan science. This is particularly apparent on the materials and applications fronts, as described above, but parallel advanced are also being made in the fields of computing and even biology. The effects of IT have already transformed the entire process from design to construction to maintenance, and even more profound changes will occur with the predicted increases in processing power which nanotechnology will create.

Surinder Mann