By Tom McDonough

Between March and September of 2007, Ajax Paving Industries, Inc., was moving faster at Chrysler’s Chelsea Proving Ground’s high-speed oval track than the cars that are tested there. That’s because the company, one of the leading asphalt paving and manufacturing companies in Michigan, was charged with rebuilding the more than 50-year-old track and turning it into a state-of-the-art testing facility.

“The reconstruction’s goal was to provide excellent ride quality, improved safety, and defined pavement friction within a compressed construction time frame,” says Len Becker, Project Engineer for Wilcox Engineering. “The existing oval was 60 feet wide and constructed of concrete pavement. The new reconstructed oval is 75 feet wide in the straight-aways and 81 feet wide in the curves.”

The project proved quite a challenge for Ajax. It was the first time Chrysler performed a total makeover of the 4.71-mile track, originally built in 1953 and located just south of Interstate 94 near Chelsea, Michigan. It also was the first time Ajax was contracted to pave a structure with a parabolic design.

Not a straight shot

“Normal roadways are paved flat,” Ajax Project Manager Brad Hillard says. “Your standard asphalt equipment is flat. But this oval essentially was one big curve or cup. We had to purchase special equipment and modify existing equipment to pave asphalt in that parabolic shape.”

That equipment included a fully automated Vögele 4M Parabolic Screed and specially designed Vögele Super 2100 paver to tow it. “They were two of the big reasons why we did such a good job on the turns and top parabolic lanes,” says Clarence Jones, Ajax’s Estimating Manager on the job. “We got the best pieces of equipment that we could get.”

The goal was to provide excellent ride quality, improved safety, and defined pavement friction.

The purchase of the screed wasn’t easy, Jones says. Ajax found it in Mexico, and Al Farnia, Vice President of Construction, and John Stockwell, Equipment Manager, traveled there to inspect it and start the procurement process even before the Chrysler contract was in hand. After getting the screed through customs, it was transported to Pennsylvania for refurbishment, a process that involved bringing a technician from Germany to supervise the work. The screed was then shipped to Michigan in time to start paving the track. Ajax’s crew also was trained by Vögele on how to use the complicated piece of equipment prior to paving the parabolic lanes.“From the moment we decided to do this job, there was a total company commitment from top to bottom,” Jones says.

One great challenge Ajax had was supporting the equipment on the steep slope. “The challenge was twofold,” Jones says. “We had to keep the equipment from sliding down the slope, but we also had to develop a system that allowed our equipment to travel smoothly so that it could perform its construction operations to the exact precision necessary to meet the track’s tight design specs.”

Ajax had to modify rolling equipment to handle the track’s parabolic curves. The work included putting outriggers on the rollers, making feeder adjustments to the paver, fixing hold up equipment with hydraulic cable systems, and adjusting these systems to meet our changing project demands on the steep 35-degree inclines. “We also used a roller on the top flat surface of the oval and ran cables from it to the rollers on the slopes to steady them and hold them in place,” Jones says.

Exacting standards

To produce the stringent friction requirements Chrysler demanded, and to create a durable riding surface, Ajax used three different asphalt mixes, placing approximately 72,000 tons of asphalt.

“We used a 13A RAP (Reclaimed Asphalt Pavement) asphalt for the base; a 13A asphalt for leveling; and a 36A asphalt for the top course,” Hillard says. “Chrysler’s specification for the top-wearing course was a .92 coefficient of friction. We exceeded that criteria.”

	To produce the stringent friction requirements Chrysler demanded, and to create a durable riding surface, Ajax used three different asphalt mixes, placing approximately 72,000 tons of asphalt.

“Fifty percent of the track also transitions from flat pavement to the high-bank parabolic curves, and we were able to maintain exact design elevations to within 1/8 of an inch,” he says. “We also exceeded Chrysler’s smoothness standard for surface irregularities.”

Ajax met the accelerated project schedule — which Chrysler required because it was renting time at other tracks to test cars.

Full drainage also was provided around the underside of the track, eliminating old ditches that used to line the inside of the road surface. “Ajax met or exceeded all the project’s specifications, which resulted in an excellent final product,” Becker says.

Hillard seconds the sentiment. “This project went well because everyone was on the same page,” he says. “Our team, from the foreman to the crew to the mechanics, were committed. Our mechanics did a great job finding out what needed to be modified and making it happen.”

Challenges bring opportunities

Trying something it hadn’t done before also opened a new door for future paving projects for Ajax. “We are currently looking at a number of opportunities to use our new parabolic screed,” Jones says. “One is a track in Arizona, and we’ve had inquiries from Germany and Holland about doing work there.”

A large amount of credit for the success of this project goes to the dedicated engineering maintenance team. The team consisted of Equipment Manager John Stockwell, Lead Mechanic Rich Kiewleski, and Paving Foreman Doug Silverthorn.

“We had to make numerous adjustments early on,” Jones says, “but we were able to make them quickly without sacrificing project time or quality. John, Rich, and Doug did a great job of identifying needs and accommodating them early on.”

Another challenge with this project was obtaining the specified pavement density on the high banked parabolic turns. With Ajax’s specialized equipment, this was not a problem.

Quality and recognition

The greatest success of the project was the final ride quality. Ride quality is a term used to describe the smoothness of the track. The ride quality on this project was measured in inches/mile, which is a measurement of the vertical deviation over a section of road. The specifications for this track mandated that it have a maximum of 4 inches/mile of deviation in the high banked turns and 2 inches/mile in the straight-away sections. Ajax was able to build the track with less than .5 inches/mile, far exceeding the contract specifications. This was extraordinary considering the high level of difficulty.

	Ajax was able to build the track with less than .5 inches/mile on the entire track, far exceeding the contract specifications.

“I wouldn’t think that there are very many contractors that would come into a project like this and think that even the specified smoothness requirement was possible,” Jones says. “For Ajax to exceed the requirements the way we did is a great accomplishment and something that we are very proud of. I have to believe that the pavement at the Chelsea Oval is some of the smoothest pavement in the entire country.”

The smoothness of the new track was evident as Chrysler was able to drive a vehicle upwards of 200 mph on a windy opening day of the track, a feat that was unheard of under the previous track’s conditions. As a testament to its precision work, Ajax received an Award of Excellence in the Special/Challenging Projects category from the Asphalt Pavement Association of Michigan (APAM) as part of the APAM-MDOT Paving Awards program. Ajax once again proved up to the challenge in spite of paving on such a steep slope while trying to meet projected production rates.