Enhancing productivity, the vertically integrated Las Vegas Paving owns a fleet of trucks, so it was able to dedicate 20 sets of doubles - capable of holding up to 38 tons of millings per set - to the job. The crew kept a trailer underneath the mill's 42-inch-wide upper discharge conveyor belt. "The PR950 loaded a set of doubles in about four minutes," Mendenhall explains.
The contractor experimented with milling depths. With a 48-inch-diameter rotor, the PR950 delivers up to 15-inch deep cuts. In some areas, workers milled full depth, up to 13 inches, while other depths were set at 6 inches.
"We tested to see what depths optimized production," Mendenhall mentions. All areas of the runway and taxiway were milled to grade in either one or two passes.
"No matter whether milling at 6 or 13 inches, the PR950 milled up a very consistent material," he adds.
Las Vegas Paving found that while it was more impressive to see the cold planer mill full depth in one pass, maximum productivity was achieved at 6-inch depths in most areas of the runway and taxiway.
"It's common to achieve higher productivity numbers at shallower milling depths," comments Tom Brooks, cold planer project manager for Terex Roadbuilding. "Although the machine cuts more material at full depth, the mill's faster operating speed at shallower depths more than makes up for this loss."
In just 16 short days, the PR950 and PR800 7-12s delivered the production and durability required to complete the 300,000 ton job. Paving subcontractor ACME Concrete Paving made its first pour on November 19, as scheduled.
Las Vegas Paving left approximately 25 percent of the millings on site to be used at the Clark County Department of Aviation's discretion. According to Mendenhall, some of the recycled asphalt will be used on the $1.4-billion expansion project of McCarran International Airport Terminal 3, and the Department of Aviation blends the millings with natural material to use for embankments and to cover the infield.
The remaining 225,000 tons of millings were trucked to Las Vegas Paving's Blue Diamond asphalt plant, where they will be used as RAP (reclaimed asphalt pavement) in a number of mix designs for upcoming projects.
"We can incorporate up to 15 percent RAP in our asphalt for projects in the City of Las Vegas, Clark County and a number of surrounding communities," Mendenhall explains. With liquid asphalt prices still riding high in the $400-per-ton range, this will result in significant savings for the contractor.
Purchasing the new PR950 specifically for the McCarran International Airport project was a wise investment for Las Vegas Paving, as it paid off in a number of ways for the contractor. "We were very happy with the machine's performance," Mendenhall says. In addition to dependably tackling the grueling 22-hour schedule that the contract required, most importantly it kept this portion of the project on schedule.
Las Vegas Paving turns 50