UC Pavement Research Center eyes longterm pothole fix

BERKELEY (KTVU) -- The recent wet weather has exacerbated pothole problems in the Bay Area and governments are using make-shift patches as a temporary solution but the UC Pavement Research Center is eyeing a permanent fix.

The state legislature established the lab 70 years ago at UC Berkeley's Richmond Field Station as California was looking to vastly expand its network of roadways.

A sister lab now exists at UC Davis and the high technology labs have advanced with the times and technologies to revolutionize roadways.

"We're looking at how to make them cheaper, last longer, and reduce the environmental impact," said Professor John Harvey, who is also director of the UC Berkeley and UC Davis Pavement labs."

There are various kinds of rocks and other materials that go into asphalt and concrete roadways.

"We look at different ways to do the mix design, the proportions of the material, the properties of the rocks, the sand, the gravel, the binder," Harvey said.

The binder, or the glue that holds the chemicals together are either thick oil tar or cement.

In addition to the specific materials that are used, how the pavement is laid out can extend its life by double.

"It's not rocket science, it's really rock science," Harvey said.

So whether they are materials that the lab builds custom to test or something they cut directly out of a highway, they materials are tested to determine how they will "wear" if they are deployed.

Researchers use varying punishing test such as advanced accelerated aging techniques, where road materials are repeatedly run over by steel wheels. The results show how well or poorly the materials will respond.

UC's pavement labs helped develop a technique where the deteriorated material are reground down to the rocks and set to rebind it without having to be removed from a roadway, meaning there's no expensive hauling away of the old road.

Eventually, researchers envision roads that will be able to be recycled in place forever.

Harvey said this process can reduce a yearlong job to two or three weeks and at 25-50 percent discount.

"So we basically can reconstruct it in place quickly, cheaply and with very little impact," said Harvey, adding that "95 percent of the money that we spend, by the state and by local government, is on maintenance and rehabilitation and not more than 5 percent is on new pavement."

Harvey says pothole patching is similar to adding a headstone to a pavement that's already dead.

By KTVU reporter Tom Vacar.