Building With Waste

Recent global events have exposed the risk of relying on imported, virgin fossil-based feedstocks. Despite this vulnerability, domestic demand for recyclate remains sluggish, leaving valuable end-of-life materials undervalued and destined for landfill.

We urgently need innovative solutions that prove the worth of the resources we already have onshore. A standout example is Selwyn District Council’s recent pilot, which turned "waste" into infrastructure by using a "dry-process" asphalt infused with recycled tyre rubber.

In collaboration with partners, the Council's pilot project effectively converted a waste stream into a functional resource, using approximately 500 old tires per kilometer of road. Early findings indicate that this rubber-modified asphalt is not only a viable, sustainable alternative to landfilling tires but can also be more cost-effective due to enhanced durability and resistance to cracking, as stated by Council officials.

This innovation is part of a broader shift across the construction sector to rethink traditional materials, proving that circularity extends well beyond polymers. For instance, in 2023, Palmerston North City Council  partnered with local industry to divert over 5,000 cubic metres of waste glass from landfills, crushing it to replace natural sand and aggregate in concrete and roading projects.

Furthermore, 2024 research funded by the NZTA Innovation Fund explored using reclaimed glass as a low-carbon alternative to traditional cement and lime for soil stabilisation. By integrating these diverse waste streams into our infrastructure, we are not only solving a landfill problem but actively building a more resilient, domestic supply chain that reduces our collective carbon footprint.

These solutions demonstrate the power of shifting our mindset to view end of life ‘waste’ as valuable materials. You can read more about these initiatives by following the links below:

https://www.odt.co.nz/star-news/star-districts/star-selwyn/nz%E2%80%99s-first-rubber-road-laid-canterbury

https://www.pncc.govt.nz/News-Events/News/Council-and-Higgins-Concrete-team-up-to-transform-waste-glass-into-eco-friendly-pathways-and-roads

https://www.aut.ac.nz/news/stories/recycled-glass-for-road-construction