HONOLULU (HawaiiNewsNow) - The city is looking for ways to avoid expensive repairs on rundown roads by preserving streets before they start to fall apart.
Crews have been trying out slurry seal since 2010 to extend the life of roadways five to seven years after they've been paved.
"The slurry seal acts as though its a coat of paint. It's a coat of paint with usually some sand or some aggregate material in there to replace the material that's fallen out," said Robert Kroning, director of the city's Department of Design and Construction.
The city spends about $3 million annually for the slurry seal program. Crews are testing different materials in various part of the island.
"It seems like it's working very well. We plan on continuing to use it," Kroning said.
Meanwhile, in Pearl City, the University of Hawaii is testing several preservation treatments, including slurry seal, seal coat and crack sealing.
"There's no single magic bullet here. It's trying to apply the right technique in the right situation and it's not so easy to always figure it out," said UH associate professor of civil and environmental engineering Ricardo Archilla.
"We've taken nanometer scale polymers which allow us to make them stronger and enhance the strength of the asphalt to the degree of 10 times the normal new installation," said Dan Akiu, managing partner of Group HI, which distributes the product.
The city will monitor the site to see if there are any changes in the next four to five months. Officials said both products seemed to work well, even under challenging conditions where groundwater is constantly seeping in.
But they aren't cheap.
"Cost is always a factor. However, there are situations where we would evaluate the number of times we have to go back to do repairs and that will factor into the cost as well," said Ross Sasamura, director of the city's Department of Facility Maintenance.