To win a Sheldon G. Hayes Award for asphalt pavement takes a commitment to quality by everyone involved. And it takes the right equipment, from the asphalt plant to your trucks to material transfer vehicles (MTVs) to the pavers. For the past 10 years running, eight of the last 10 Sheldon G. Hayes Award winners have used MTVs.
The most recent winner, Staker Parson Cos., of Salt Lake City, Utah, won the award for work on approximately 8.5 miles of Interstate 15 in southern Davis County, Utah. The project called for rubblizing three lanes of concrete in each direction, overlaying them with asphalt, and adding a new lane on each side in the median. Staker Parson worked night and day – and added crews to both night and day shifts – to meet an accelerated deadline and open the I-15 project in connection with an adjacent project.
Both the overlays and the new lanes required 7 inches of hot mix topped by a 1-inch open-graded friction course. Staker Parson laid down a base course of 2.5 inches, then applied two courses of 2.25 inches each. “We did use a Roadtec Shuttle Buggy for all paving,” says Brandon LeFevre, general manager for the contractor. “It definitely helped us with our hauling asphalt in belly dumps.”
Double-bottom belly dumps hauled asphalt to the grade and dumped it in a windrow in front of the paver. Using a windrow pick-up attachment, the MTV picked up the windrow, remixed the asphalt to eliminate segregation, and transferred it to the paver. Easy, right?
Not so fast. It’s difficult if not impossible to back up the pup trailer pulled by a belly dump, so how can the paver deal with a gap in the windrow? No problem, if you have an MTV. The big belly dumps can leave a gap in the windrow, dump as close as possible to the end of the previous windrow, and keep on trucking. The MTV ensures that the gap in the windrow is no problem and that the paver has plenty of asphalt.
“The MTV helped us keep a full head of material in the paver, and we could keep the paver moving,” LeFevre said. It was a high production project; Staker Parson was running at 300 to 325 tons per hour. “We were really pouring on the coal,” said LeFevre. “We laid about 250,000 tons of hot mix asphalt, and we finished in seven months.”
Quality results were excellent. Staker Parson won 65 percent of bonus payments for smoothness, and 50 percent of the bonus payments for material quality, which was gauged by binder content, gradation and compaction. LeFevre said the MTV helps with compaction, because it prevents thermal and physical segregation.
Lindy Paving Inc., New Castle, PA, has won the Sheldon G. Hayes award three times. And for all three projects, the contractor used a Roadtec SB 2500 Shuttle Buggy MTV. For all three, Lindy won smoothness bonuses. The lowest incentive was 79 percent; the highest was 91 percent, for the 2009 winner.
The 2009 award was given for Section 35M, a 6.6-mile stretch of Interstate 79 north of Pittsburgh. The worn concrete roadway was designed to be cracked and seated. Antigo Construction used a guillotine hammer to crack the concrete at 24-inch intervals. Then the concrete base was seated with a 40-ton tow-behind, rubber-tired roller. Lindy paved a total of 18 inches of hot mix asphalt.
The Pennsylvania DOT starts its scale of smoothness bonuses at 60 inches per mile of deviation on the International Roughness Index. The highest bonus goes for 35 inches per mile or less. “We hit 27.5 inches per mile on the northbound side, and 29.2 inches on the southbound side,” said Joe Conti, quality control manager for Lindy Paving.
Dan Ganoe, Lindy’s operations manager, said it’s important to maintain a consistent paver speed through a shift. For Section 35M, the contractor could pave from bridge to bridge within one shift, so no transverse joints were necessary. Distances per shift ranged from 1 to 5 miles.