Waterproofing New Zealand roads

October 2015

Water damage plays a major role in "flushing" , the slick bitumen -rich patches often seen on the road surface. Water can disbond the bitumen from the stone surface, which under the action of traffic migrates upwards. Photo: Opus.

Opus International Consultants (Opus) has been awarded $3 million by the Ministry of Business, Innovation & Employment for a research project aimed at modifying chip seals so there's less chance of them being damaged by water. This will reduce annual maintenance and construction costs for water-damaged roads.

The funding, over four years, will enable a team of researchers from Opus Research, the University of Auckland and the Australian ARRB Group to create and test a type of impermeable membrane and other technologies that that will prevent water from entering the pavement and causing damage.

Opus Research Leader Peter Benfell says New Zealand’s road network is highly susceptible to water damage with more than 90% of our roads constructed from chip seal construction. New road surfacing technologies have good potential to extend the life of New Zealand’s roads and save the government millions over the next decade.

New Zealand’s economic growth, travel safety and social wellbeing are absolutely dependent on maintaining a high-quality road transport network. The government spends about $1.3 billion a year on road maintenance and up to a third of that can be traced to water damage. Within 10 years, the success of this research could save the country as much as $80 million dollars a year," says Mr Benfell.

"The project has strong support from the New Zealand Transport Agency, and senior construction industry leaders will also be part of the project team. Opus hopes that the research will lead to a new industry standard for road surfaces in New Zealand and overseas.

"Opus is proud to be working alongside other research and industry leaders. These new products could generate export revenues for New Zealand and reduce domestic road construction and maintenance costs to free up resources that the transport agency could use to further optimise and modernise the road network.”