Soil stabilization meets nuclear power plant needs

by Greg Udelhofen
Created: July 22, 2008

Asphalt Busters constructs new, refurbishes existing wastewater and evaporation ponds at Palo Verde Nuclear Power Plant in Phoenix.

After a grading contractor spread and compacted the treated material on the sloped side walls, the entire pond was covered with a two-layer liner to seal it from any leakage.
After a grading contractor spread and compacted the treated material on the sloped side walls, the entire pond was covered with a two-layer liner to seal it from any leakage.
For the pond construction, Asphalt Busters used a level mixing area adjacent to the pond structure to spread over 200 truckloads (4,550 tons) of the cement additive (which was applied at a rate of 8...
For the pond construction, Asphalt Busters used a level mixing area adjacent to the pond structure to spread over 200 truckloads (4,550 tons) of the cement additive (which was applied at a rate of 8 percent of the total combined volume to be mixed) and then injected over 1.4 million gallons of water at 200 to 425 gallons per minute to the treated soil before mixing to a depth of 12 inches in order to produce 55,000 cubic yards of material for the sloped side wall construction.
"The entire site is under a microscope as far as total emissions being released into the environment," says Dan Selby with Asphalt Busters. "That required some modifications to the skirting around the...
"The entire site is under a microscope as far as total emissions being released into the environment," says Dan Selby with Asphalt Busters. "That required some modifications to the skirting around the mixing chamber of our reclaimer/stabilizer, and the emissions output of our equipment was also monitored."
Water was immediately injected into the mix on a pass following the cement placement, then the water was unhooked to make a final 12-inch-deep mixing pass over the material. This was done to...
Water was immediately injected into the mix on a pass following the cement placement, then the water was unhooked to make a final 12-inch-deep mixing pass over the material. This was done to minimize the possibility of dust emitting from the site.

Selby's stabilization crew used a CMI/Terex reclaimer/stabilizer on the project and worked with a grading contractor who placed and compacted the mix on the slopes.

"We not only had to add rubber around the skirting of the mixing chamber, but we also modified the vane feeder of the cement spreader in order to drop a thicker layer of cement in order to control dust," Selby says. "We immediately injected water into the mix on a pass following the cement placement and then unhooked the water to make a final 12-inch-deep mixing pass over the material. Working closely behind the cement spreader again minimized the possibility of dust emitting from the site."

Stabilization expertise
Asphalt Busters has 11 reclaimer/stabilizers in its fleet designed primarily for soil stabilization work.

"We do a lot more soil stabilization than road reclamation," Selby notes. "Most of our road work is pulverization with an occasional full-depth reclamation project.

"A lot of the soil stabilization work we get involved with is either site prep for building projects or parking lot and roadway stabilization," he says. "We used to be in the grading and paving business, but the stabilization business is really a specialty that was needed in this market and one that requires a full commitment in order to deliver the quality customers want."

In 2007, Asphalt Busters provided its soil stabilization expertise to 125 different contractors. Most of the projects were in Arizona and New Mexico, but the contractor does partner with another stabilization contractor in California to provide the equipment and service capabilities required to execute certain types of projects.

"We can provide equipment and technical assistance (operators) that can support a grading contractor who requires our expertise in order to successfully bid and construct a job," Selby says. "We have lime slurry equipment to stabilize soil conditions, and that's something most grading and site prep contractors just don't have in their equipment fleet. So, we're in a position to fill a very specialized niche."

As a specialist in asphalt pulverization and soil stabilization, Asphalt Busters is in a position to provide grading and paving contractors with a service that saves those contractors time and money.

From building pads to parking lots to traffic-bearing surfaces and everything in between, Asphalt Busters is in a unique position to provide contractors with a solid foundation.

"If the existing soil conditions are less than desirable, you can't build a quality project unless you make sure you're building on a quality foundation," Selby says. "We may not be the lowest price, but we believe we're the best at what we do. And any contractor who's going to stake their reputation on building a quality project is going to make sure they're building on a quality foundation."