The Centre for Regenerative Design and Collaboration (CRDC) is addressing two major environmental problems – pollution and the need for sustainably sourced sand, with one clever solution.
During lockdown, the CRDC worked on a small pilot plant in Cape Town that converts unrecyclable waste plastic into an aggregate. This aggregate, in turn, offers a sustainable alternative to sand in the concrete industry.
The Costa Rica-based company aims to reduce plastic pollution in the environment by cleaning up rivers, beaches and oceans.
It hopes to operate a large-scale facility by June 2021 that will be able to process up to 48 tonnes of waste plastic per day.
“The environmental benefits are significant. I mean not only are we pulling waste plastic out of the environment but we’re also replacing sand, which is the second most traded commodity globally and it’s in short supply,” global CEO Brett Jordaan said.
Jordaan explained that sand utilised in concrete must have irregular grains in order to help with cohesion, which means it is typically sourced or mined from sensitive areas such as riverbeds and beaches – which gives rise to growing pressure on the industry to find sustainable alternatives.
“We can take vast quantities of unrecyclable waste plastic across all of the different types – it can be dirty, messy and co-mingled – and we turn it into a high-quality synthetic sand which goes into concrete and makes the end products stronger, lighter and better insulating,” he said.
Jordaan said the concrete industry is 30 times larger than the global plastics industry. He said they’ve calculated that if they replaced only 2.8% of the sand used in the industry, they’d “absorb all the plastic on earth”.
Washed up nurdles
Earlier this year tons of nurdles – the raw material used by manufacturers to make plastic – washed up on beaches across the east coast of South Africa after a vessel allegedly lost its cargo somewhere off Plettenberg Bay. These bits of plastic can’t be recycled and are often ingested by birds, fish and other sea creatures.
In order to help with this, the CRDC, in collaboration with the Pristine Earth Collective, volunteered to accept all the nurdles collected along beaches and use them along with all the other types of waste plastic to make their sustainable aggregate.
“All of those nurdles cannot be converted into anything useful so we said they’ll be perfect for our feedstock. We’re actually developed to take beach clean-up waste and so we agreed to take all of the nurdles collected across South Africa,” Jordaan said.
The waste is delivered to the site either by waste management companies, NGOs or waste picker networks the company is still busy establishing, where it’s sorted into different types, chip packets, lids, etc.
It’s then pre-treated to kill off any pathogens and to eliminate odours.
The plastic is shredded and added to a special mix, after which it is run through a machine that heats the material and transforms it into grey “cheese puffs”. The end product is dried and ground up, leaving an aggregate or sand alternative.
“Our end product, resonate, is mixed in the concrete mix – concrete is stone, sand, water and cement – so we replace some of the sand and stone in that mix and it can go into any concrete product,” he said.
Jordaan hopes their work will not only have an environmental impact, but positively impact the socio-economic situation in the country as well.
“Our goal is to source as much waste as possible from the informal sector, whereby we can effectively help to alleviate the stress on those underserved communities and create jobs at the same time,” he said.
