Zero Waste hits the road as NPDC trials plastic roading system

07 June 2019

It may look like an ordinary stretch of inner-city road, but below the surface, New Plymouth’s Liardet Street contains an innovation that could lead the next recycling revolution.
 
World-leading technology is being used to take waste plastic from NPDC’s kerbside recycling collection in New Plymouth and mixing it into asphalt to make a new type of road resurfacing.
 
NPDC, EnviroNZ, Road Science and Downer have partnered to test the new material, Plas Mix, on a section of Liardet Street leading up to Pukekura Park. 
 
The project, a New Zealand-first, has been driven by New Plymouth District’s vision of Zero Waste, says NPDC Infrastructure Manager David Langford.
 
“It looks just like an ordinary road surface, but there’s actually the equivalent of more than 83,300 yogurt pots inside,” Mr Langford says.
 
“After China stopped accepting the world’s recycling we found it increasingly difficult to sell our 3-7 plastics. Instead of stockpiling or landfilling these plastics, we took this as an opportunity to innovate and come up with a better solution, which is where the idea to put it into asphalt came from.
 
“Road Science laboratory testing has shown the new material is stronger and should perform better than standard asphalt while also being cost effective, but the proof is in a real-world trial on our roads. So we’ll be monitoring closely how it performs over the next several months.”
 
Murray Robertson from Road Science says: “The creation of Plas Mix is a collaboration between two commercial companies actively working together to solve significant local and global waste minimisation issues. The team are tasked with developing a meaningful outcome that can successfully repurpose waste plastic while not compromising the integrity of the pavement solutions.” 
 
Mr Langford says finding a local solution for 3-7 plastics is an opportunity to take ownership of the end use of a difficult waste rather than exporting it for someone else to manage.
 
“Previously we’ve had to pay to export these plastics more than 10,000km to be recycled overseas. For this trial, the plastic has only travelled about 10 to 15km from where it was picked up at the kerbside to finishing its journey on Liardet Street, which is much more sustainable for our environment.
 
“If this proves successful, there’s the potential to reuse a big portion of our region’s residential waste plastics locally here in Taranaki. That will be much more sustainable in the long-run, saving our ratepayers money and cutting our carbon footprint as well as taking a huge step towards us becoming a Zero Waste district.”
 
This is the first time in New Zealand that residential plastics have been incorporated into road resealing, with 500kg of residential plastics being used in this trial. 
 
Both asphalt and plastics are made from crude oil.
 
Liardet Street Plas Mix road trial