How carbon could combat Wellington’s earthquake-prone buildings

There are currently 595 earthquake-prone buildings in Wellington, according to MBIE’s register. Photo/Mark Mitchell

A new earthquake-strengthening technology could be the carbon-laden silver bullet for Wellington’s shaky buildings.

Research funded by Toka Tū Ake EQC has found that by wrapping weak spots in the walls of high-rise buildings with carbon fibre straps, they can be boosted to well above the demands of the building code – and it’s cheap as well.

Research supervisor Dr Enrique Del Rey Castillo told NZME the carbon fibre used to earthquake-proof the buildings is similar to that used on expensive things like rockets or helicopters but it’s cheaper.

“It’s not as expensive as the carbon fibre that goes into rockets, but this is still more expensive weight than steel or concrete for example – the thing is, because we use so little of it, it is very strong and because we can reduce the labour involved with installation it becomes much cheaper.”

It’s also much faster than things like concrete – the work can be completed in just a few days.

“That is unthinkable with materials like steel or concrete.”

It works by stopping the inner walls of a structure from buckling under the pressure of an earthquake. Once they are wrapped in carbon, the building can double its safety rating.

“We have completely suppressed that failure [of the walls buckling] and it can display naturally all the way to 5 per cent when the [building] requirement in the New Zealand Standards and guidelines is 2.5, so it’s two times what the standard requires.”

He said his team had a lot of support from industry players like Concrete NZ, Mapei, Sika, Holmes and BBR Contech, who are all extremely interested in the research.

Head of research Dr Natalie Balfour said many older commercial buildings are being converted to apartments, so it is vital to ensure that people live in homes that meet modern earthquake standards.

“Toka Tū Ake EQC decided to fund this research because it will deliver practical guidance on how at-risk walls in older buildings can be strengthened cost-effectively. It will also establish a consistent way of doing these fixes across New Zealand.”

Overall, there are currently 595 earthquake-prone buildings in Wellington, according to MBIE’s register.

The deadlines for strengthening these spike in 2027 when 200 notices will expire.