Anicet Mbida 06:52, 09 June 2023

Anicet Mbida gives us every morning what is best in innovation. This Friday, he is interested in an invention that could improve the air quality in tunnels, depolluting concrete.

Today's innovation could improve air quality in tunnels. Because there is now a depolluting concrete.

Thanks to it, we will be able to transform the walls of the tunnels into air purifiers. All this, without installing a device. It is the concrete itself that will be able to eat the pollution of the exhaust pipes.

This is possible thanks to what is called photo-catalytic concrete. It works a bit like the catalytic converter of cars. That is to say, it will break down polluting particles (nitrogen oxides, sulfur oxides and other junk that come out of exhaust pipes), and it will transform them into completely harmless substances.

One immediately imagines the interest in a tunnel. Everyone knows that pollution is much more concentrated on the roadside. But it is up to 1000 times worse in tunnels, simply because the air circulates badly. But with this new concrete, the air could become a little healthier.

And it's effective, we tested it?

Yes. We completely recoated the inside of a tunnel with this new concrete. Measures were taken and after 24 hours, there was an 18% reduction in pollution, including the famous NOx, the ultra-carcinogenic nitrogen oxides.

In addition, this concrete treatment does not degrade over time. It is resistant to washing, rain and foams that could cling. It therefore does not need any specific maintenance. A superb advance developed by researchers at the Korean Institute of Civil Engineering.

But it's going to be very expensive, so it's going to limit its use?

Well, no, for once! So yes, it costs more to make this concrete photo-catalytic. But not much: only 5 to 10% more. Its price therefore remains reasonable which could facilitate its widespread dissemination.

We have indeed talked about tunnels. But it could also be used as a building material whether for walls, bridges or sidewalks... In fact, everything that is built of concrete today could be transformed tomorrow into a depolluting surface.

It is true that it is better to vegetate than to concrete. But when you have no choice, it is good to know that there is now a depolluting concrete.