Concrete is everywhere. For every person in the UAE, about two tonnes of concrete are produced every year. It goes into buildings, roads, dams, bridges, walkways, parkways - all the infrastructure around us.
But while concrete is flexible in its applications, the material itself is very brittle. It can withstand amazing amounts of pressure, but when stretched or bent, it cracks and breaks. That rigidity makes it costly to use and maintain.
Reinforced steel bars (rebar) help, but at a high cost - and even then there is significant and costly wear and tear. Even in the UAE, where most of the buildings are relatively new, the concrete repair market is already worth about Dh183 million a year. That number is expected to balloon as weathering, foundation shifts and other phenomena take their toll as the buildings age.
If concrete could be made both more flexible and stronger, the savings could be huge.
A good deal of research is already focused on achieving that. But one area that has garnered little attention despite showing significant promise is the combining of nanotechnology with materials science to create carbon nanotube-strengthened concrete.
Carbon nanotubes are carbon atoms arranged in tiny cylinders measuring one ten-thousandth of the diameter of a human hair.
In this form, they are 100 times stronger than steel, lightweight and able to transmit electricity and heat. Instead of running them through the concrete every few centimetres, as with rebar, the concrete can be made so it is full of millions of these tiny but resilient rods.
My project at the Masdar Institute, sponsored by the Qatar National Research Foundation, is investigating the properties of this nanotube-strengthened concrete.
Our preliminary research has found that it can be not only stronger and more flexible, but also better able to withstand stretching and bending without cracking or breaking.
Also, the nanotubes' thermal and electrical properties make it possible to build smart concrete structures that can sense any damage or failure.
Our team is digging deep to design the ideal nanotube-strengthened concrete. To be able to model the behaviour of millions of nanotubes packed into a section of concrete, we have created a specialised computer programme that can virtually generate random dispersals of the nanotubes.
We are also looking to include two other materials - carbon nanofibres and polymer microfibres, which are each an order of magnitude larger than carbon nanotubes and would add more dimensions of strength and flexibility to the material.
Preliminary studies have found that this can produce concrete that is five times as strong and durable as normal. Additionally, to reduce its environmental footprint, our material would use industrial waste - such as fly ash produced from coal burning and "slug" powder from steel factories - in place of energy-intensive cement powder. Globally, reducing cement production even by 1 per cent would be equivalent to taking millions of cars off the road in carbon output.
One challenge is make concrete in which the carbon nanotubes are evenly dispersed and properly bound in. If the nanotubes clump together in one area, it could lead to weaknesses in other parts. And if the carbon additives fail to properly bond with the rest of the concrete ingredients, it could result in structural weakness.
To mitigate these issues, we are collaborating with an American industrial giant, Lockheed Martin, to "grow" the nanotubes directly on the cement particles and the micro fibres, thus ensuring a strong bond and even spread.
It is our hope that with this research we can help make the UAE's structural projects stronger, longer lasting and more sustainable. This will not only help save massively on material and repair costs, but also make buildings better able to withstand earthquakes and other potential structural impacts. With this research, we can help make crack-free, steel-free concrete part of our near future.
Dr Rashid Abu Al Rub is an associate professor of mechanical engineering at the Masdar Institute of Science and Technology