Project profile: Giordana Velodrome
The Giordana Velodrome project exemplifies Carolina Floors’ commitment to quality and craftsmanship. Not all concrete contractors could have finished this job. In fact, the plans alone scared away most of the companies looking to bid the project. When the Rock Hill Parks, Recreation and Tourism Department announced the construction of the velodrome, it was the largest concrete job in a 150-mile radius and created a buzz among concrete contractors in the area.
“Then the plans came out with a 45-page method statement from the architect on how the job was to be constructed,” Rogers says. “Upon most of the people looking at the plans and reading the method statement, the excitement on the street changed to ‘We don’t want to fool with this.’ That narrowed the competition. In the end there were only four bidders.”
Rogers says a few things attracted him to the velodrome project. First, the site is only three miles from Carolina Floors’ headquarters. Second, it was a highly complex project. “The thing that intrigued us from the start is this work, in the finishing stages, is all by hand. There is no mechanical equipment used in the finishing aspect of this track,” Rogers says. It was the kind of project that required a talented team of concrete craftsmen.
Carolina Floors won the bid for the concrete work. The general contractor on the project was Leitner Construction, Rock Hill, S.C., and the formwork and rebar contractor was Kempf Contracting, Indian Trail, N.C. German firm Schuermann Architects built the design; the company has been designing wood and concrete velodromes around the world since 1926. The general contractor also hired an onsite engineer who shot thousands of points with a total station over the course of the project.
The velodrome is an 820-foot (250-meter) oval-shaped track. Its banks rise as the track curves into a turn and lower coming out of a turn. One slope rises to a pitch of 42 degrees, making it the steepest outdoor velodrome in the United States. In addition to the sloped walls, the design also incorporates a convex cup that allows racers to achieve higher speeds than they could achieve on a flat track. The bikes that race on this track can travel up to 44 miles per hour.
The track was constructed in a series of 50 17-foot-wide panels, 27 feet long. Each panel included a 5,000 psi, 4-inch base slab with a 2-inch max slump, poured at a rate of five panels a day. Once the base slab was in place, the rebar and formwork contractor placed double mat No. 4 rebar 4 inches on center and put in the edge forms. Working at a rate of one panel a day, Carolina Floors crews placed a 10-inch-thick, 5,000 psi concrete with a 2-inch max slump with crane and bucket, vibrated the slab and struck off. A rolling tent kept the sun from drying out each slab so crews could then place a 1.5-inch grout topping wear surface on top of the 10-inch slab in a wet on wet application.
Placement of the grout topping was a unique challenge for Carolina Floors. Each batch of grout mixture consisted of 188 pounds of cement, 575 pounds of sand and only 6.5 gallons of water. The German architect called it “earth damp.” And Carolina Floors crews mixed and placed 14 batches of the grout each day via a “bucket brigade” — a line of men that handed off the grout from the mixer up the panel with 5-gallon buckets. Once they placed the grout, crew members screeded the topping with a German-designed aluminum screed and hand finished with wooden hand floats. Crews spent roughly two hours a day placing the 10-inch subbase and six hours a day placing and finishing the 1.5-inch wear surface.