The purpose of this research was to identify the barriers to using tyre-derived crumb rubber in bitumen binder in New Zealand roading and the methods to remove these barriers to create market demand for New Zealand waste tyre-derived products.
As a result of the comprehensive literature review and stakeholder consultations, it was found that the key barriers in New Zealand were high initial cost of specialist equipment, the relatively small market, security of supply and implications of the industry’s switch to emulsion binders.
Fortunately, with a growing appetite for better performance in roading infrastructure and continued technological advancement, a number of solutions were identified. These include growing the use of modified binders over the network and investigation into the use of devulcanised rubber.
The combination of these proposed changes will effectively remove the barriers identified and allow tyre rubber to be incorporated into the New Zealand roading network cost effectively and enable this waste stream to be diverted away from landfills.
Keywords: asphalt rubber, bitumen, chipseal, crumb rubber, devulcanisation, emulsification, end-of-life tyres, polymer modified binders (PMB), viscosity