This research project, undertaken in 2006 to 2008, confirms that traffic can force water through first-coat chipseal surfacings that do not visually show signs of cracking.
The research measured the change in moisture content after rain on a number of newly sealed sites. Although this testing showed a statistically significant increase in moisture over all sites, the increase was not dramatic.
The research concludes that water ingress can occur where a water film collects on the pavement. The film of water can occur either through rutting of the pavements, or if the crossfall and longitudinal shape is such that a sheet of water forms above the surface texture of the pavement.
Keywords: chipseal, moisture, New Zealand, pavement failure, potholes, rutting, waterproofing