When O&G Industries Inc. of Torrington, CT was contracted to place a new asphalt surface on the Lime Rock race track, it called for a strategic vision to complete the task under a tight schedule. A pair of new Vision 5203-2 pavers from Vögele America Inc. — abetted by three Hamm Oscillation compactors — worked to a tight schedule in June as they reconstructed the pavement of Lime Rock Park race track near Lakeville, CT.
The track’s $5-million project is very ambitious, attempting to do, in the words of its publicity department, 90 days of work in 31 days. O&G Industries was paving the 1.53-mile track as part of an overall upgrade which includes capital improvements to structures.
“We’re doing two things: we are repaving and surfacing the ‘Classic Lime Rock’ track, which is the original mile-and-a-half track; and we are adding two optional, 40-foot-wide, more technically difficult sections of track that are slated for faster prototype cars that can go too fast on the classic track,” says Joe Sauer, director of operations and technology, Lime Rock Park.
The “classic” track includes seven turns in a park-like setting free of grandstands and bleachers; instead, patrons may wander around the grounds, change their vantage point, get close to the drivers, or relax in the shade.
Since 1957 Lime Rock Park has hosted almost every form of motorsport, including Trans-Am, formula racing, Grand-Am Rolex Sports Car Series events, SCCA regional races, NASCAR Busch East Series, American Le Mans Series, the annual Rolex Vintage Festival every Labor Day, and the annual Ferrari Racing Days in July. It also hosts the Skip Barber Driving School for future and “wanna-be” race car drivers.
Project began with milling
The track was milled by Costello Industries Inc., using one of its Wirtgen W 2100s. Asphalt millings were kept on site and placed on unpaved roads throughout the park, where they will knit together in the summer sun, creating a usable, stable driving surface.
On the Lime Rock Park project, two Vision 5203-2 pavers were used in tandem, to provide consistency of pavement side-to-side and ensure a hot longitudinal joint between lifts.
The track left most of the decisions up to the contractor, but stipulated that the two pavers used in echelon had to be similar machines, with the same tractor and same screed. O&G rented the second paver.
Compaction was being performed by two Hamm HD O90Vs and a rented HD O90V.
Breakdown behind the paver was being done with vibratory action, followed by oscillation after the mat cools down, and along the joints.
“The mix falls within the specifications we’ve developed for race tracks,” says Brian Prowell, P.E., principal engineer, Advanced Materials Services LLC, Auburn, AL, designers of the mix and quality assurance/quality control managers. AMS was performing QA testing on the mix and density, as well as developing specifications and overseeing the work.
“It’s a 12.5mm, 75-blow Marshall mix,” he says. “We tend to use Marshall mixes on race tracks, because they have a little higher asphalt content and we need that adhesion to resist the lateral forces and raveling that we get under race cars. We milled 1.75 inches over most of the track, going deeper in some areas, and are placing this mix 1.75 inches compacted to 94-percent density.”
Two material transfer vehicles were being used to separate the pavers from the trucks, and to preclude thermal segregation.
Paving in echelon
Paving in echelon is ideal for eliminating the longitudinal joint, created down the middle of the mat when a hot lift of asphalt is placed adjoining one that was placed earlier and has become cold.
“Paving in echelon eliminates the longitudinal joints,” Prowell says. “The Vögele pavers are doing a very good job of putting out a nice mat. I like the quality of the mat; it’s uniform, and even with the screed extensions out, it’s putting down a uniform texture mat, which is what we want.”