Last week, Ryan and I watched a marvellous mobile machine that turned chunks of ripped up concrete into gravel. We assumed it would then be used for hardcore – the bottom layer of roads and paving – and it’s a nifty way of locally recycling a material that might otherwise go to landfill. But it’s also an example of downcycling, turning a waste product into a new material, but one of lower quality than the original. Recycling office paper into toilet paper is a good (hypothetical, I don’t know if it happens) example of downcycling.

Concrete blocks

It reminded me that permaculture people have been recycling waste concrete for some time; I remembered blog posts from years ago about ‘harvesting urbanite‘ and ‘how to recycle concrete into urbanite‘. That’s not a new idea, of course. Local people have been recycling disused building for as long as people have been disusing buildings – there’s many a famous ruin that has contributed stone to more prosaic building efforts nearby. The RISC roof garden in Reading is home to some stones that were originally part of Reading Abbey.

Sunny herb bed
Herb bed made from concrete blocks

But whilst it might be obvious, and even trendy, to reuse proper stone, concrete has always been a lower value material, and waste concrete seen as nothing but waste. Which is a pity, because if concrete was a country it would have the third largest carbon footprint (2.8 billion tonnes). [It’s worth noting that food waste would also be the third largest emitter if it was a country. It pips concrete slightly, weighing in at 3.3 billion tonnes a year, according to the UN in 2013.]

The modern world is built on concrete, which is why the Guardian is in the midst of a special Concrete Week, exploring both its contributions to global architecture, and the impacts it has on environmental and human health. There are high tech ways to recycle concrete, one of which involves zapping it with lightning to separate it from other materials. What’s currently lacking is a commitment to a circular (zero waste) economy.

Capitalism’s laser-like focus on profit ignores any detrimental effects that it doesn’t have to pay for, which is why things don’t change until consumers demand it. It’s hard to tell whether the world is ready to demand sustainable concrete (or a move towards more sustainable materials), but there have been some success stories in terms of plastic, which has been making headlines for some time now.

UK bread bag recycling scheme

Hovis and Terracycle have launched a Bread Bag Recycling Scheme, which will see drop-off points being created for any LDPE plastic bread bags. Community groups will be able to collect bread bags for ‘recycling points’ that can be redeemed for cash. There’s an FAQ on the Terracycle website. It’s also possible to mail your breadbags to Terracycle once you have created an online account. Terracycle, shredded and wash the bags and then turn them into pellets that can be “used for a number of moulded rigid plastic products like benches, or used as film for products such as rubbish bags.”

UK crisp packet recycling scheme

Last year there was a campaign which involved mailing empty (and unrecyclable) crisp packets back to Walkers, which caused the Royal Mail some distress. It worked, though, because Walkers have also created a recycling scheme with Terracycle, which will recycle any brand of crisp packet. Again, there will be drop off points, community groups and charities can benefit from collections, and you can mail (properly packaged) crisp packets to Terracycle for recycling. Apparently, the crisp packets are “cleaned and shredded to turn them into plastic pellets. These pellets are then transformed into park benches, plant pots, watering cans and cool bags.”

UK contact lens recycling scheme

And Terracycle has also partnered with Acuvue to create a recycling system for disposable contact lenses and their packaging. You’ll be able to drop off your waste as a participating optician. Terracycle currently have too many people wanting to mail theirs in individually, but you can apply to become a drop off location. They’ll accept any waste from any brand of disposable contact lenses. Again, the waste will be cleaned and turned into pellets which can then be used to manufacture new plastic products.

So… three new recycling schemes, three new waste items that don’t have to be sent to landfill, progress towards the circular economy and proof that consumer pressure can make a difference. I’d call that a win. Now all we have to do is make sure we buy recycled plastic products where possible!

(And, actually, if you follow Terracycle on Twitter, you’ll discover they have a whole host of recycling schemes for individual products, so they’re a big help for zero waste people.)