Giant, white blocks can be seen by drivers on Highway 101 near Fairview Avenue in Goleta, and the polystyrene segments will be used to support a new highway offramp being built in the area.
The expanded polystyrene blocks, which weigh 70 pounds a piece, are stronger and more dense than Styrofoam, Caltrans engineers say.
The blocks will be used to support the roadway over the ramp and slope in a place where a large amount of dirt would be normally.
The effort is part of the Goleta drainage project, the goal of which is to improve the capacity of two large drainage culverts along Las Vegas Creek and San Pedro Creek at Highway 101 west of Fairview Avenue.
The agency is working with the Santa Barbara County Flood Control District as well as the city of Goleta, Caltrans spokesman Jim Shivers said.
Work is also being done to prevent flooding and increase water capacity north of Calle Real and Highway 101.
The work will also include reconstructing the highway’s southbound offramp at Fairview Avenue, where the blocks are now located.
If the weather permits, construction is expected to be complete by early 2016 and the ramp opening is expected in late December. A new drainage channel will run under the ramp and freeway lanes.
After the blocks are assembled, they’ll be covered with a thin layer of lightweight dirt. At the base of the sloping hillside will be the re-opened southbound lanes of Highway 101.
Shivers said that the polystyrene material is flammable, but would be sealed in dirt “so they would be unlikely to burst into flame.”
A protective membrane will also be placed around the blocks to keep gasoline and any other flammable materials away from it.
The material doesn’t break down, so “essentially this stuff will theoretically last forever,” Shivers said.
Assuming no solvents such as gasoline penetrated the membrane, “it would last for hundreds of years.”
The blocks “are extremely strong and lightweight,” he said, and a fraction of the weight of soil, which means the amount of weight the structure is loaded with is significantly reduced.
It’s difficult to quantify the cost savings with using the polystyrene, but maintenance was a main factor in the choice, according to Shivers.
“We could have built a traditional structure to handle all that weight, but it would have been difficult, if not nearly impossible, to reliably inspect all of the critical surfaces for wear and tear,” he said.
— Noozhawk staff writer Lara Cooper can be reached at lcooper@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.
