Kiwi company turns plastic waste into high-quality concrete

Enviroplaz director Stephen Swart (left) and founding director Peter Barrow at their factory in Manukau. Photo / Dean Purcell.

A New Zealand company is turning plastic waste into high-quality concrete.

Plazrok, the brainchild of south Auckland-based company Enviroplaz, is unique in that it can transform absolutely any type of plastic into a rock-like substance that forms the aggregate of concrete.

"We don't take the labels off, we don't have to disassemble it or take any of the other components off it, we can use it in its entirety," said Enviroplaz founding director Peter Barrow.

"We don't even need to clean it - the process we put it through does everything for us."

What's more, concrete companies would not have to change their processes at all in order to use the Plazrok in their product.

Yet they would end up with concrete that is 10 to 40 per cent lighter than usual. That spells big savings.

"For example, when they were building Britomart ... there were 7000 truck movements between Wiri and Britomart in order to deliver that concrete. If you decreased the weight by 20 per cent you've dropped that down to 5000 trips. Think about what that does for your industry, for the roads, for your diesel usage, for your tyre savings," Barrow said.

Plazrok concrete had strengths comparable to conventional concrete, while offering seismic advantages.

"There's no reason that we should be chucking plastic in the oceans or rivers, or in landfills," Barrow said.

The company's managing director is former cycling champion Stephen Swart, famed for being the first person to blow the whistle on drug cheat Lance Armstrong.

Swart saw huge potential in the product, particularly as a way to reduce environmental waste.

"All we're doing is substituting the aggregate, which gets mined out of hillsides, with this material," he said.

"So we're saying it can all come here ... no plastic needs to enter landfill anymore."

Enviroplaz has developed another innovative plastic product, Plaztuff, which could have big implications for the construction industry.

Barrow said Plaztuff was seven times lighter than steel, and can also be used in place of stainless steel, aluminium, fibreglass or plywood, yet does not rot, rust or corrode.

There's no reason that we should be chucking plastic in the oceans or rivers, or in landfills.

Peter Barrow, Enviroplaz founding director

It has been used to build boats, barges, swimming pools, quarrying and aggregate bins, truck tankers, and even an art sculpture.

"We can build a truck tanker that's almost as competitively priced as a steel tanker, and yet you don't have to paint it, it doesn't rust and it doesn't rot so the maintenance cost is a lot lower" Barrow said.

"The production time is also lower because it's lighter material so it's easier to handle. So suddenly we've got a material that not only reduces the end user's cost but reduces the [cost] implication for the people building with it."

Plaztuff is made from a base of polyethylene residue with a master batch of "secret herbs and spices".

"If you took an aluminium boat and you took a sledgehammer to it you'd ding it. If you took a sledgehammer to this it won't do a thing," Barrow said.

What's more, it's completely recyclable.

"And in 30 years time we can buy this material back and reuse it in exactly the same process by re-grinding it."

The company is in talks with Siam Concrete in Thailand, which is interested in utilising both products.

Barrow had met with Thai Ambassador Maris Sangiampongsa, who saw the business as an opportunity to strengthen business ties between the two countries.

"We basically see Plaztuff and Plazrok as a global technology - the local market has been our test ground, our proving ground ... as part of the journey to get us on a global march," Barrow said.