Scientists have designed a “skin” that senses when concrete structures are damaged

Image: Bittbox via Flickr, reproduced under creative commons.

Concrete is pretty great, isn’t it? It’s strong, it’s cheap, it’s easy to use. Let’s hear it for concrete!

On the downside, though, it’s also prone to cracking – if there are swift changes in temperature, for example, or if it’s bearing too much weight. Cracks in concrete structure are annoying at the best of times, but if said structure is holding, say, nuclear waste, they can also be disastrous.

So a team of scientists from North Carolina State University and the University of Eastern Finland have developed plans for a “skin” that would flag up cracks or damage to the concrete’s surface. Their idea involves installing electrodes at the edges of a structure, then applying electrically conductive copper paint across the concrete. The electrodes would emit a constant, low-level current across the surface of the painted “skin”, monitored by a computer. If the surface was weakened, cracked or damaged, the paint would become less conductive, and the computer would sense a change in the signal. You can even analyse the data to produce a map of the damage.

Here’s a cracked piece of concrete, alongside a computer rendering of the damage:

Image: Aku Seppänen.

So far, the researchers have only tried the method out on small, 1m long pieces of concrete, but they’re hoping to test on bigger areas. Dr Mohammad Pour Ghaz, one of the paper’s co-authors, said the team were keen to show the method could work on “real-world structures”.


There’s a kickstarter campaign to fund a reprint of the British Rail design manual

A mock up of the British Rail branding book. Image: Wallace Henning.

Way back last year CityMetric brought you news of a couple of fundraisers with a simple dream – to bring the New York subway graphics manual available to anyone who wanted to buy it.

That, it turned out, was a lot of people: the campaign raised over $250,000 on its first day alone. People, it seems, really, really love a spot of transport design.

Since then others have been taking notice. Just last month a similar project raised over six times its funding target at almost a million dollars in order to make available reproductions of the original NASA branding papers.

But what about the design fans based in the UK, we hear you ask: can they, too, get their government-issue font-based kicks?

Well, now they can. This Kickstarter campaign wants to bring the British Rail corporate identity manual to a coffee table near you.

The campaign wants to republish documents from the 1960s, a decade in which time British Rail underwent a branding overhaul. Introducing the now-iconic “double arrow” logo, the BR design team set about creating a modern, consistent corporate identity across the mammoth network.

Reams of diagrams and graphic templates were produced, specifying the minutiae of everything from trackside architecture, to uniforms, to stationery. If it meets its funding target, the new clothbound hardback will bring together approximately 220 original diagrams. You can see the thing on this site here.

Will this fundraiser be as successful as its stateside cousin? As we write it has reached about a third of its target with one month to go.

One might assume that the customer buying into the New York Metro branding and all of its connotations might represent a rather different demographic to the British Rail equivalent. BR was many things, but it was never particularly cool.

But perhaps with time, its connotations of shabbiness are ebbing in favour of a distinctly British nostalgia. Who else could look back with even a vague fondness for leaves on the line and the wrong kind of snow? No mention as yet of whether the unique specifications of a British Rail sandwich will make it into the finished book.

You can find out more about the Kickstarter campaign and donate here.

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All images: Wallace Henning.