National Corvette Museum’s Motorsports Park gets the smoothest and most consistent track surface possible from Trimble grade control and 3D paving systems
Scotty's Contracting and Stone is a premier paving, grading, and aggregate company headquartered in Bowling Green, Kentucky. The contractor provides full paving and excavation services for commercial sectors across the region.
The National Corvette Museum, also located in Bowling Green, Kentucky had a vision to construct a motorsports park to be used by car and motorcycle enthusiasts as well as driver training and product testing. The organization hired Scotty’s Contracting to pave complex and reconfigurable tracks. Looking to keep pace with frequent design changes and deliver the smoothest and most consistent racetrack surfaces, Scotty’s Contracting adopted machine control and 3D paving technology from Trimble.
The team adopted Trimble’s Business Center - HCE, Trimble’s PCS900 3D paving control system, and the Trimble® GCS900 Grade Control System for grading and bulk excavation.
- 25% increase in productivity with 3D grading and paving technology from Trimble.
- Saved $150,000 to $200,000 in staking and survey costs, using one surveyor instead of five
- Built better 3D surface models of racetracks in Business Center - HCE; made design changes quickly for greater paving accuracy and production
- Laid complex designs including super elevation transitions and track intersections with exceptional smoothness for Le Mans style tracks
- 3D grading and paving allow for precise control of aggregate quantities− zero cost overruns
Since the Chevrolet Corvette was introduced in 1953 it has sparked America’s imagination and become a national symbol of ingenuity, speed, and style. The National Corvette Museum was founded by a non-profit organization to celebrate the legacy of America's sports car and to share its history and future innovations with generations to come. In addition to the museum, the complex is also home to the new Motorsports Park.
The primary configuration of the racetrack is a 3.1 mile (5 kilometer) total loop, which can be reconfigured into a separate 1 mile (1.6 kilometer) loop and 2 mile (3.2 kilometer) loop. The site also includes a 9.5 acre (3.8 hectare) reconfigurable track area. The tracks are used for product testing and for various recreational car club events.
In addition, these road tracks are Le Mans style tracks ― where the elevation changes are frequent and cover about 30 feet (9.1 meters) from top to bottom. Unlike other racetracks, these road tracks can be run at different configurations based on the event. However, the paving must be such that the track is smooth and consistent, regardless of which configuration the cars are traveling.
It’s no surprise that when the National Corvette Museum foundation was looking to pave its racetracks, Scotty’s Contracting and Stone was the ideal choice. Headquartered in Bowling Green, Scotty’s Contracting is the premier paving, grading, and aggregate company in the region. The company is a veteran Trimble user with several years of experience using Trimble’s Universal Total Stations, 3D milling systems, and the Trimble® GCS900 Grade Control System on its graders and dozers. With a tight timeline and complex design, Chris Higgins, engineering manager for Scotty’s Contracting, realized paving the racetrack using traditional staking methods was simply not an option.
“For this project there were multiple changes we had to keep pace with. We noticed certain things that needed to be modified for a smooth and consistent surface, and the Corvette Racing team made several changes throughout the project,” said Higgins. “With Business Center - HCE we were able to update the model and, in short order, have it delivered to the machines in the field, where they could immediately begin working off the new design. It really helped us keep the flow going. Not only that, for this signature Corvette track we wanted it done perfectly, and we knew that 3D paving technology from Trimble would and give us the smoothest and most consistent surface possible.”
Working with Trimble reseller and partner SITECH Mid-South, Scotty’s Contracting outfitted two pavers with the Trimble PCS900 3D system. Using Business Center - HCE the team is able to transfer the design data to the PCS900 system. The PCS900 then references the surface model and automatically controls the paver screed to the correct grade and slope per the design.
In May of 2013, while the design was being still tweaked, the team began clearing the land and moving dirt. Higgins and his team completed bulk earthworks using dozers and excavators equipped with Trimble GCS900. In total they moved 13,500,000 cubic feet of dirt (half million cubic yards).
“Given the unique challenges of this project, the excavation would have taken several months longer without the aid of Business Center – HCE and Trimble machine control. There is no doubt that we would not have finished on time,” said Higgins.
Higgins estimates he is also saving $150,000 to $200,000 in staking costs because he is able to rely on one surveyor instead of four or five. This one person is now responsible for loading all of the files and surface models into the machines and grade checking.
“Just about every machine we used at the Corvette track was equipped with Trimble machine control so that when we had changes, we would just update the model in Business Center - HCE,” said Higgins. “We could get models completed and out to the field quickly using wireless data transfer, so productivity increased a significant amount because the machines were updated automatically to the correct grade, following the updated design.”
Scotty’s Contracting also helped design a special blend of highly polymerized hot mix asphalt for the track called the 82-22 mix. Because the team was paving a racetrack, as opposed to standard road width, Higgins and his crew had to adapt.
“In most places the track is 36 feet (11 meters) wide and in some places up to 40 feet (12 meters) wide, which cannot be done with one paver,” said Higgins. “To eliminate a cold joint in the middle, we ran two pavers in echelon equipped with Trimble 3D paving systems, each following a material transfer vehicle for nonstop paving. With that system and Trimble technology on our pavers, we were able to get the ultimate and smoothest track surface possible.”
25% greater production with Trimble
The team followed the pavers with four rollers to complete the compaction of the asphalt. In total, Scotty’s Contracting moved .5 million cubic yards, laid 60,000 tons of blacktop and 85,000 tons of base stone. Following this process the final paving work was complete, a full 20 days ahead of schedule. Higgins estimates at least a 25% increase in productivity with 3D grading and paving technology from Trimble.
This is primarily due to the fact that his models are faster and easier to build and the operators have all of the information they need to be productive right in front of them. Compared with manual methods, today his operators can take fewer passes to achieve a higher quality surface. Essentially, operators can reach the appropriate depth and cut all the subgrade and stone and then pave the base courses with 3D paving, using a minimal amount of all material.
“On a lump sum project such as this, if you miss the tonnage by even a little bit, it can be disastrous because the cost of the extra material needed comes straight out of the contractor’s pocket,” said Higgins. “With over 145,000 tons stone and asphalt used on the Motorsports Park, we were less than 0.5% off on our estimated tonnage, which is phenomenal. Over-running those numbers, even by a little, could easily have cost us hundreds of thousands of dollars.”
Producing a smooth, highly-consistent, racetrack
Higgins and the National Corvette Museum staff were also extremely impressed by the exceptional quality of the racetrack surface. Any problem areas were identified early and the team used Business Center - HCE to adjust the model and smooth the areas out.
“Paving is a difficult task because hot mix asphalt is very fluid when laid and the screed behind a paver floats, making it a chore to control,” said Higgins. “But with the 3D paving system from Trimble, we are able to remove a lot of those variables and make modifications where we see slight inconsistencies in the mix or in the speed of the paver.”
Scotty’s Contracting successfully completed the racetrack paving project ahead of schedule in June of 2014. Higgins explains that because of the lateral strain of the surface, the team wanted to allow sufficient time for the asphalt mix to cure before it was driven on. The Motorsports Park enjoyed its official grand opening in August 2014, which kicked off the 20th anniversary celebration of the National Corvette Museum.
“We’ve had consultants out here who have built the Talladega and Daytona 500 tracks, and they were very impressed with our paving and incredibly smooth surface,” said Higgins. “The amazing part is you can barely tell where the joints are; that’s not something I’ve ever seen before until we used Trimble’s 3D paving technology.”