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”.

 
 
 
 

15 other things ministers could move to London to boost the Northern Powerhouse

The Angel of the North. Wouldn't it look better in, say, Camden? Image: Getty.

Yesterday brought confirmation that the government had come up with a clever way of boosting its flagship “Northern Powerhouse” policy: move over 200 government jobs to London.

From the Mirror:

The Tories sneaked out a plan to move 228 jobs in the Northern Powerhouse department from Sheffield to London today, on the last day before Parliament breaks for recess.

And the department today suggested staff who want to keep their jobs could commute the two-hour each way journey from the North to the capital.

(...)

The plan, described as “madness” by Nick Clegg, will see the Department for Business Innovation and Skills’ (BIS) Sheffield office shuttered in 2018.

This is not the first time large chunks of public investment has quietly been shifted from the north to London, even as ministers repeat the words “Northern Powerhouse” in a convincing tone of voice. Remember the decision to move the National Photography Collection from Bradford to London?

It’s easy to sneer. But actually, there are some very clever and compelling arguments for gradually moving every job in Britain into the area enclosed by the M25. Larger cities, after all, are more productive. It stands to reason, then, that a country in which all economic activity took place in a single, high-rise postcode would be far richer, happier, and, well, better than the one we’ve got at the moment. 

That probably isn’t realistic. What might be, however, is gradually shifting all the north’s myriad attractions to new locations in the Home Counties. For that reason, CityMetric understands that ministers are considering relocating a number of other key economic assets to the south of England. 

The Yorkshire Dales – As things stand, England’s “landscape capital” has been disproportionately concentrated in the north. To rectify this, Her Majesty’s Government will explore plans to redistribute the Dales to southern Essex.

Alnwick Castle – Following the very successful experiment in which we moved Leeds Castle to Kent, we’ve found a very promising site for Alnwick just outside Hove.

Betty’s of Harrogate – We believe this charming tea room would do far better business somewhere in the vicinity of Park Lane. 

The Angel of the North – The iconic Antony Gormley statue is currently going to waste on a slight incline next to the A1, on the outskirts of an obscure place called Gateshead. It would attract far more visitors if we placed it instead on, say, Primrose Hill. The best thing about this plan is that we wouldn’t even have to rename it.


The Cavern – To improve Liverpool’s tourism figures, we will be consolidating its main attractions into the new “Abbey Road Experience”.

The rest of Harrogate – Bit confused they didn’t put it in Oxfordshire in the first place, actually.

Salford Quays – Moving chunks of BBC Production to Greater Manchester has been very successful. Her Majesty’s Government is keen to build on this success: we the best way of doing so would be to consolidate operations and seek efficiencies by re-locating the whole of Salford Quays to London. An ideal site has been located in the White City area.

Tate Liverpool – The present site is far too inconvenient. A new site, closer to the Tate Britain, would be ideal.

The University of Durham – It’s in a picturesque medieval town, it’s broken into colleges, it has a boat race... The perm sec was a bit surprised to find it wasn’t in the Home Counties already, if we’re honest.

While we’re at it:

The University of York – See above.

Coronation Street – The problem with this show is that it’s set in Manchester. It’s just so bloody dreary, isn’t it? All that rain; all those cobbles. They should set it in London. Make something more cheerful, like Eastenders.

Hadrian's Wall, in its original location. Image: Hulton Archive/Getty.

Hadrian’s Wall – The wall was constructed during the reign of the Emperor Hadrian to protect proper Britain from the savage Scots. Today, though, there are no fewer than 54 Scottish Nationalists in the House of Commons. This suggests that, if we’re going to bother with such defensive measures, we’re going to need them a damn sight closer to the capital than they are at the moment. 

The Settle to Carlisle line – I mean, it’s a lovely route, but it doesn’t really go anywhere. It’d almost certainly get more passengers if it ran from, say, Euston to Milton Keynes.

Pies – Treasury cost/benefit analysis suggests that large quantities of carbs and gravy would be used more efficiently in the south. 

Northerners – We considered moving the jobs to the people, but decided this way round would work better. Great for house prices, too!

Please note that Her Majesty’s Government has abandoned plans to incentivise Manchester United to move south. But we are hoping to tempt Leicester City to a new home in Surrey.

Jonn Elledge is the editor of CityMetric. He is on Twitter, far too much, as @jonnelledge.

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