Plaster work

EU-funded project adapts micropolymer technology for self-sealing wall board as part of safety measures range for buildings in earthquake zones. Siobhan Wagner reports.


A hi-tech villa designed to resist earthquakes by self-healing cracks in its walls is being built on a Greek mountainside as part of a £9.5m EU-funded project that includes materials specialists from Leeds University.

Leeds’ NanoManufacturing Institute (NMI) is playing a crucial role by developing plaster board walls that contain nanoscale polymer particles, which will liquefy when squeezed under pressure, flow into cracks and harden to form a solid material.

The team hopes this will help further the development of inexpensive earthquake-resistant structures for some of the world’s most susceptible areas.

‘The use of micropolymers has been around for quite a long time,’ said NMI chief executive Prof Terry Wilkins. ‘The concept of pressure-sensitive polymers is also quite well known in the polymer industry, but putting them in this much smaller form in these situations is unknown. It’s completely novel.’

The most innovative and challenging part of the project for the researchers will be to model and design polymer nanoparticles that can be incorporated into the plaster matrix as the board is being made.

‘One of the things we want to do is encapsulate these polymers in little fibres, but we’re still working on a design and materials for those,’ he said. ‘Once we have the optimum design, we will be able to start producing thousands of litres of nanoparticle fluid, adding just a tiny percentage to the plaster board mix.’

While the home’s plaster board is a completely innovative design, Wilkins said that will not be the only unique part about the project house. Its walls will be constructed with novel, load-bearing steel frames.

‘The internal frames will be a lightweight steel, not wood,’ he said. ‘The external frames will be a heavyweight steel that uses magneto-resistance fluid to provide damping in the foundation of the building.’

The villa will also be equipped with wireless, battery-less sensors and radio frequency ID tags to collect and transmit data such as stresses and vibrations, temperature, humidity and gas levels affecting it.

While the nanopolymer particles are expected to fill in cracks and help prevent wall degradation, the sensors, which will be imbedded in the plaster board, will monitor how well they are doing their job.

‘If you’ve got a house on a rumbling fault, eventually the constant shaking over time causes microcracks,’ said Wilkins. ‘With traditional plaster board these cracks will eventually cause degradation.’

Construction and observation studies on the villa is due to be complete by December 2010, but until then, Leeds and its 25 partners will test their materials on an experimental sub-unit of a house built on the campus of the University of Athens. The majority of its findings are likely to be gained in this simulated environment, said Wilkins, ‘because you can’t guarantee that you’re going to get an earthquake on cue.’

Wilkins said it will be exciting to see the results of the project because there is potentially a good market for these homes — especially in the US and the far east.

‘Their cost is not going to be exorbitant,’ he said. ‘Their real advantage is they are going to be competitively priced.’ He added that as far as the actual manufacturing there would not be so much concrete for foundation. So there would also be an environmental benefit.

While these types of homes would definitely be of use to people living near fault lines, Wilkins said he has tried to discover if there is interest in these types of homes from those in the chemical and construction industry who are located in less earthquake-susceptible areas of northern Europe.

‘I told them they ought to look at this type of house because it focuses on the sort of low-energy, low-carbon footprint homes they have there,’ he said. ‘Some of these technologies we are creating in this project would fit those models too.’