Smart materials: how could they transform infrastructure intelligence?
Author: Ioanna Papanikolaou, Business Development Manager – R&D and PhD Candidate at the University of Cambridge
Every year in the UK we spend billions of pounds repairing and maintaining our vital infrastructure1. But new, smart materials could enable us to cut those costs, improve sustainability, and the safety of major project delivery.
I’m part of a team conducting ground-breaking research into the use of nanotechnology in construction. I’m looking at how materials with biomimetic attributes, that is, materials that mimic nature2, can be used to reinforce structures such as bridges and tunnels. These new composite materials change in response to environmental conditions and could, therefore, look after themselves.
Why do we need smart materials?
Let’s take concrete as an example. Concrete, the most widely used construction material, is strong, durable and relatively inexpensive but it also needs frequent repair and maintenance when it’s used in structures that need to last decades. In the UK, many infrastructure owners and operators conduct visual inspections of their assets to determine what work may need to be carried out. But this is a time-consuming and costly process that can cause disruption to the public and put inspectors at risk.
In recent years, high-tech sensors have been used to gather data on the condition of structures remotely. But these sensors are often expensive to install and they also need to be maintained throughout the life of the asset. For this reason, I’m looking for an even smarter way to design and build our road and rail infrastructure, dams and water pipes and our homes and offices.
The smart solution: self-sensing materials
My work focuses on addressing these challenges using the relatively new material, graphene, which could reinforce concrete at the nano level. Graphene based materials are strong, have very high thermal and electrical conductivity, and are impermeable to gases3. This means they could improve the durability of concrete structures. They could also initiate advanced functionalities, such as a self-sensing mechanism. Self-sensing concrete would be able to monitor its own condition and identify if there’s any damage, and it can do this without the use of external sensors4. So what does that mean in practice?
I’m proposing that if graphene based materials are added to concrete at the right dosage, the section of bridge we’ve built, for example, will conduct electricity. If the concrete is then damaged, there’ll be a break in the conductive network and the infrastructure owner will be informed that damage has occurred at the specific location. In this way, the number of unnecessary inspections will be reduced and targeted repairs can take place.
Materials with a self-sensing mechanism have many applications. Take an airport for example: a graphene-reinforced concrete could help the operator reduce the time and costs involved in de-icing and repairing its runways. If electricity is used to increase the temperature of the runway it will reduce the airport’s reliance on de-icing salt, which is currently used to keep the runways open in cold weather. It will also prolong the life of the structures, which are often damaged through use of salt in winter.
We’re also investigating how graphene-reinforced concrete - and soon, plastic - could help operators in the water sector. The network of pipes that supply us with clean water are susceptible to damage. We’ve been asked to develop a self-sensing material that could detect weaknesses and, therefore, enable companies to get more of the precious resource to its customers instead of losing it through leaks. If the Government and operators are spending less on fixing broken pipes, they can target their investment in other areas.
Will graphene-reinforced materials reduce the impact of construction on the environment?
The benefits of self-sensing materials could also extend beyond repair and maintenance. We’ve just published the first lifecycle assessment for the use of graphene in concrete5. We found that using graphene as a nano-reinforcement is 248 times less damaging in terms of global warming than the use of Portland cement.
In addition, our analysis showed that if adding graphene to concrete resulted in a 5% reduction of Portland cement, the effect on global warming would reduce by 21%. This makes its potential as a reinforcement material even more exciting.
So what’s next?
We’re planning to conduct a live trial of the use of graphene in concrete within the next few years but self-sensing materials are just the first step in our journey towards safer, more sustainable and cost-effective construction materials. We’re also developing self-healing materials and together the technologies have the potential to transform the industry. If we return to the example of the bridge I mentioned earlier, imagine if the concrete not only recognised it was damaged but also triggered the self-healing mechanism. This would enable repairs and maintenance to be carried out autonomously.
So how close are we to bringing this to fruition? We’ve worked closely with academia, colleagues, partners and suppliers over the past three years and we’ve been able to accelerate our research into smart materials and help to ensure nanotechnology advances in line with industry best practice, not in isolation. As a result, we hope some of the infrastructure we build in the next 10 to 15 years, or even the structures we repair, will be able to take care of themselves.
For more information
More detailed information on my research can be found on the Institution of Civil Engineers website. Or please do get in touch with me to find out more.
I’d also like to hear your thoughts on the potential of new, smart materials. Do you think they will transform the way we build and maintain our infrastructure? And if so, how do you think they should be applied?
My role at Costain
I’m part of Costain’s Research, Development and Innovation team that is creating smart infrastructure solutions to address some of the most pressing challenges society has ever faced. In a collaborative approach, Costain has created a community of PhD students across leading research organisations, clients and business partners to ensure we meet our clients’ needs and that ideas come to market through a proven route so we can deliver maximum impact.
- 1 http://www.infrastructure-intelligence.com/article/aug-2018/uk-government-spent-£189bn-infrastructure-projects-new-figures-reveal
- 2 https://www.icevirtuallibrary.com/doi/full/10.1680/icsic.64669.613
- 3 Novoselov, K. S. et al. (2012) ‘A roadmap for graphene’, Nature. Nature Publishing Group, 490(7419), pp. 192–200. doi: 10.1038/nature11458
- 4 Horszczaruk, E., Sikora, P. and Lukowski, P. (2016) ‘Application of Nanomaterials in Production of Self-Sensing Concretes: Contemporary Developments and Prospects’, Archives of Civil Engineering, 62(3), pp. 61–74. doi: 10.1515/ace-2015-0083
- 5 www.elsevier.com/locate/jclepro