Barcelona is covering a road bridge with concrete that eats pollution

Image: BCQ.

Converting horrible bits of concrete transport infrastructure into green spaces has become a bit of a trend recently. In Hamburg, there's talk of turning a motorway into a park; then there are the dozens of attempts to piggyback on the success of New York's High Line by creating pedestrian walkways and parks.

But one Barcelona bridge is trying something a little different: it's keeping its cars, but introducing a host of sustainable green technologies to make it much, well, nicer.

The Sarajevo bridge is a member of what is surely the grimmest category of urban infrastructure: a road bridge over another road, to the north of the city centre. At the moment, it looks like this:

Under a plan commissioned by the city government and developed by architects BCQ, however, it's due to be transformed. It'll still be a road bridge, but its surface will be paved with pollution-eating "photocatalytic concrete". The pedestrian walkways will be widened so they can be used as plazas, while greenery-covered walls and a canopy will shield users from the noise of the six-lane road below. The bridge will also be entirely self-sufficient, with solar panels on the bridge powering LED lights.

Here's a mock-up of the new bridge as seen from the road below:

And a cross-section:

Click for a larger image.

There's no completion date for this project, which is one of a number of schemes intended to green currently unattractive bits of Barcelona. But it does have the backing of the city government, so unlike so projects that come with cool concept images attached it may actually happen.

We're most fascinated by the smog-sucking concrete, which uses the energy of the sun as it strikes the road to break down pollutants into neutral substances like water, oxygen and nitrates and sulfates; these stick to the surface, and are later washed away by rain.

This probably won't make much of a dent in the pollution produced by the roaring highway below, but every little helps. 

All images: BCQ Architects.

 
 
 
 

Podcast: Second city blues

Birmingham, c1964. Image: Getty.

This is one of those guest episodes we sometimes do, where we repeat a CityMetric-ish episode of another podcast. This week, it’s an episode of Friday 15, the show on which our erstwhile producer Roifield Brown chats to a guest about life and music.

Roifield recently did an episode with Jez Collins, founder of the Birmingham Music Archive, which exists to recognise and celebrate the musical heritage of one of England’s largest but least known cities. Roifield talks to Jez about how Birmingham gave the world heavy metal, and was a key site for the transmission of bhangra and reggae to western audiences, too – and asks why, with this history, does the city not have the musical tourism industry that Liverpool does? And is its status as England’s second city really slipping away to Manchester?

They also cover Birmingham’s industrial history, its relationship with the rest of the West Midlands, the loss of its live venues – and whether Midlands Mayor Andy Street can do anything about it.

The episode itself is below. You can subscribe to the podcast on AcastiTunes, or RSS. Enjoy.

I’ll be back with a normal episode next week.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and on Facebook as JonnElledgeWrites.

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