Asphalt a sticky trick for recycling operation

Black asphalt is going green.

Old pavement, worn and cracked, generally ends up heaped in the Lockwood landfill. The common black road paving material contains oil that keeps it pliant, but also adds an element of gooey-ness that had stymied recycling efforts.

But Q&D Construction Co. of Sparks found a way to reclaim that waste stream. It welcomes the rubble of ripped-up roads at Q&D's construction yard off the Mustang Exit on Interstate 80. With $1.3 million in crushing equipment, the operation can handle 350 tons of material per hour.

"We'll take all we can get," says Q&D President Norm Dianda. "We think it's the right thing to be doing because it goes to the landfill."

He's spreading the word to other contractors in an effort to get more grist for the mill.

The operation's byproduct is profit.

"We'll charge to take it," says Mike Douglas, general engineering division chief estimator, "and charge for base going out."

The market, he adds, dictates the price of the base materials that are sold after recycling is complete. Aggregate base varies in price between $4.75 and $6 per ton, says Douglas.

Meanwhile, Q&D needs to charge less than the landfill so that builders will bring material its way. The price to dispose of old concrete and asphalt at the landfill varies from $3 to $5 a ton depending on quality, says Douglas.

"The reality is that it has to make financial sense," says the 16-year construction veteran.

When Douglas initially pitched the idea to Q&D, the cost of recycling was greater than the value of the resulting base material. So he held that thought until trends converged to make crushing viable.

As landfill costs climbed, other factors came into play. Local transportation officials specified a base material of recycled materials in building guides.

Meanwhile, Q&D itself was generating and wasting ever increasing volumes of old asphalt and concrete through its own demolition work.

The operation got under way last year when Q&D rented equipment from Kimball Equipment Co. in Sparks. After some experimenting to find the best approach, Q&D purchased the equipment.

While crushing concrete is nothing new, asphalt posed a different problem.

In a more common process, highway contractors mill the asphalt on-site during rehabilitation and use the millings as shouldering material.

Asphalt has long been recycled locally as recycled asphalt product when crushed asphalt is fed back into plant mix.

Q&D uses a horizontal shaft impactor to recycle asphalt, which tends to stick, into baser. As material is fed, paddles sling the rock to a set of steel bars. The combination of speed and impact crushes the rock.

But only certain types of fill need apply. Wood or plastic debris, in any amount, is not accepted.

Douglas says the process can handle some rebar, which is plucked out by a big magnet. But too much long rebar gets wrap-ped round and round like thread binding a home vacuum cleaner. Larger, embedded rebar requires another machine in effect a gigantic jackhammer to break it up.

The final product is a recycled aggregate that meets specs for most road and building construction sites.

"Anything to be covered by asphalt, or concrete slabs," says Douglas.

Ideally, recycling efforts find a reuse for everything, much as sausage makers are said to use every part of the pig but the squeal.

Q&D's operation at Mustang reaches out to the adjoining Ready Mix Inc. concrete plant to use its truck washout as grist for its mill, says Dianda and even uses the washout water for on-site dust control.