Rubber in roads
The Transport Sector Research Fund has approved and is funding a research project to identify the barriers to using tyre-derived crumb rubber in bitumen binder in NZ roads. This project also aims to understand the mechanisms to remove these barriers to create market demand for NZ waste tyre-derived products.
Internationally tyre-derived crumb rubber has become a common alternative additive to bituminous binders since the 1970s, addressing pavement performance issues as well as tackling the disposal problem of end-of-life tyres. While early trials of crumb rubber in both hot mixed asphalt (HMA) and chip seal pavements have resulted in mixed performances, technological advances and ongoing research and practices internationally have demonstrated that crumb rubber can be effectively incorporated into road surfacing.
In New Zealand, rubber has only been used in the form of natural rubber latex or styrene-butadiene-styrene block copolymer (SBS) from around the 1970s. Crumb rubber from waste tyres has not been used to any extent in normal road pavement maintenance or construction.
Recycled aggregate waste research
Together with local government, academia and industry partners, the Transport Agency is co-funding a research project into the use of recycled aggregate at the Centre for Infrastructure Research at the University of Auckland. The aim of this project is to determine the size of the Auckland recycled aggregate market, the type of materials available, and what recycled materials might be suitable for use as aggregates in roading.
There are two work streams associated with the project. The first stream is to understand the nature and engineering performance of current recycled aggregate within the Auckland market. The second stream focussed on guiding roading providers, consultants, contractors and suppliers to increase their uptake of recycled aggregate materials.
This research will help to create a better understanding of what recycled materials the market can actually supply. This will ultimately reduce the need for virgin use, transport of quarried materials and landfill disposal costs for recyclable materials.
Published research reports
- NZ Transport Agency Research Report 219 Recycling of materials for more sustainable road construction
- NZ Transport Agency Research Report 306 Assessing the Environmental Effects of New and Recycled Materials in Road Construction
- NZ Transport Agency Research Report 308 Environmental impact of industrial by-products in road construction – A literature review
- NZ Transport Agency Research Report 309 Trials of the use of recycled hot mix and ground tyre rubber in hot mix asphalt
- NZ Transport Agency Research Report 345 Contaminant characterisation and toxicity of road sweepings and catchpit sediments: towards more sustainable reuse options
- NZ Transport Agency Research Report 351 The effect of adding recycled glass on the performance of basecourse aggregate
- NZ Transport Agency Research Report 406 Quantifying the benefits of waste minimisation
- Research Report 482 Fleet management commitment to fuel efficiency
- Research Report 558 Epoxy modified bitumen chip seals
- NZ Transport Agency Research Report 560 - Reduced bitumen application rates using bitumen emulsions
- Research Report 578 Removing barriers to the use of crumb rubber in roads
- Transit New Zealand Technical Memorandum: TNZ TM 6001 v1 - Use of Reclaimed Tyre Rubber in Asphalt (preliminary report)
Useful links
- branz.co.nz/REBRI_RRC (tool to evaluate different recycling and disposal options)
- wasteminz.org.nz
- targetsustainability.co.nz
- nothrow.co.nz
- Recycled Crushed Concrete in Pavements IPENZ seminar June 2015
For further information contact environment@nzta.govt.nz .