Significant new research is being undertaken to find affordable methods of waterproofing road surfaces. Richard Silcock reviews a four-year research project.
With road freight volumes increasing by 2.5 percent annually and extreme rainfall events perhaps becoming more prevalent, the New Zealand Transport Agency and local authorities are looking for new and innovative ways to futureproof and maintain the affordability of the road infrastructure.
On average $1.3 billion is spent each year by the NZTA and local and regional authorities on road maintenance – that can be largely attributed, either directly or indirectly, to water damage. According to NZTA figures, almost 90 percent of the road network is susceptible to water damage.
Under a four-year research project being carried out by Opus Research at its laboratory in Petone, work is focused on a non-permeable membrane which restricts water entry while also providing a skid resistant surface.
The $2.7 million research project which started in October 2015 is being largely funded by the Ministry of Business, Innovation and Employment with assistance from NZTA – and in consultation with a number of contractors around the country, including Downer, Higgins and Fulton Hogan. The research is also being carried out in collaboration with the University of Auckland and with some assistance from ARRB Group (Austroads research division).
Phil Herrington, a senior road pavement scientist with Opus Research who is leading the research, says one year of research has certainly confirmed that roading seals used in the past have not been particularly effective in their water