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”.


Ordnance Survey has turned its maps into printable colouring sheets

Non-map geeks, turn away now. 

As you might have noticed, colouring books for adult have become A Thing of late. Whether as a way to calm anxiety, or a tool for those who just want to feel like a real artist without any of the effort, the books of black and white line drawings are now a trend bordering on phenomenon. 

And now, Ordnance Survey, the UK mapping agency, has piled in on the fun. From the OS blog:

We regularly hear from OS map fans who can happily spend hours poring over maps and planning new adventures and we wondered whether that activity might produce similar alpha brainwaves. The networks of roads, rivers and buildings that form the towns and cities of Britain make some complex and detailed patterns – and surely it could be fun to colour them in too?

Using black and white vector maps stripped of street names, the OS has created a series of printable black and white maps which can be coloured in. At the moment, you can choose from London, Southampton, Milton Keynes, Cardiff and Edinburgh, each in two different levels of detail. All can be downloaded and printed out here. There are even maps molded into the shape of the OS logo. 

Here's an example of a part-coloured city from the OS blogpost:

Well that's our weekend sorted, then.