How can the construction industry help in the war on plastic?
There has been a fair bit in the media recently about excessive use of plastic. It’s a topic you may have seen getting much more coverage than the environmental challenges of the construction industry, despite the fact that these challenges are significant.
This is understandable. We need homes for our survival, so perhaps people don’t want to think about the environmental impact of building them. It’s much easier and more palatable to think about something we can influence more easily – something like using less plastic in our day-to-day lives.
And yet it may be that one environmental problem can help solve another. Scientists are working on a way to put plastic waste to good use while reducing the use of sand in construction.
Sand poses a problem. Across the globe, we extract billions of tonnes of sand and gravel each year to make concrete. As you might already know, the rounded, well-eroded sand grains found in deserts are of no use. It is the angular sand grains in riverbeds and on beaches that are used.
But dredging beaches means that coastal towns are more likely to suffer from storm damage.
And aside from this practical reason to leave sand where it is, there is also the issue of how much sand is available to us.
The world’s rivers carry around 20 billion tonnes of sediment each year. But we use 27 billion tonnes of sand and gravel in construction annually, according to an estimate by the Organisation for Economic Co-operation and Development (OECD), and our usage is rising. On top of this, we use 13 billion tonnes in roads, coastal developments and land reclamation.
Clearly this isn’t a sustainable rate of consumption. So how can we cut down on the amount of sand being extracted?
Researchers at Bath University say that up to 10% of sand in concrete can be replaced with recycled plastic without having a significant impact on structural integrity.
Using plastic in this way is potentially a step forward, but it doesn’t address the problem fully and I do think we need to consider where the plastic will go when the building is demolished. Can it be used again, perhaps to form an aggregate?
I will be paying close attention to how these issues are being tackled, and I would be interested to hear your opinion.
Is reducing the use of sand and gravel the most pressing concern, or are there other issues we need to look at?
In the meantime, if you need assistance with the structural elements of an upcoming project, please do get in touch.