For professional racing drivers plying their trade at speeds of more than 200 miles per hour, it’s safe to say that paving smoothness counts.
That’s what presented a challenge to Sunmount Corporation, the Justin, TX-based paving company chosen to handle resurfacing at the Texas Motor Speedway, the nation’s second largest sports facility.
Owned and operated by Speedway Motorsports Inc., the Fort Worth facility features dual-banked turns angled up to 24 degrees, and a 1.5-mi. (2.4 km) long track designed to handle both NASCAR and Indy-style racing events.
After hosting its first event in 1997, the track underwent a full reconstruction in 1998. A complete resurfacing was scheduled again in the summer of 2001.
Given the project’s demands, the job couldn’t be given to just any contractor. That’s why Texas Motor Speedway called upon the Sunmount Corporation.
Sunmount, a concrete and asphalt paving contractor, was founded in the early 1980s. With more than 200 employees, the company has four to five crews working at any given time.
Though not specifically geared toward racetrack construction, Sunmount has gained considerable experience with related jobs in recent years.
“We got involved with the parking lots and some of the other outside work for the speedway facility,” said Danny James, Sunmount’s mechanical supervisor. “Based on our work, they asked us to bid on the track portion of the job. Though we had never paved one before, we got the contract.”
This first job presented quite a learning curve, but the results won Sunmount yet another job.
Sunmount began the job by milling off the top 4 in. (10 cm) of asphalt to install a 1.5-in. (3.8 cm) open drainage layer.
“After experiencing rainfall, they were having problems drying water off the track,” said James. “The open drainage layer was put in place to minimize this problem. As water wicks up through the ground, it comes to the open drainage layer, which directs the water into a drainpipe.”
Following the completion of the open drainage layer, the track was ready to pave. But unlike regular highway jobs, raceways present the challenge of paving at an incline. This problem was not as apparent on the track straightaways, which feature a five-degree slant, but it is definitely a concern with the 24-degree high bank turns.
“We have to keep the paver and roller steady on the slope,” said James. “Any slips or jerks are transferred directly into the mat and can cause flaws in the driving surface.”
To prevent the equipment from slipping, James developed an anchoring system for both the paver and roller. A pressurized hydraulic arm was connected between mobile crane and the paver to ensure steady placement of the hot mix asphalt. A similar system was used for the roller.
“We have a pressurized hydraulic arm that we added to the roller to keep it in place,” said James. “We used a rubber-tired roller in the infield to anchor our Bomag roller. The rubber-tired roller didn’t do any rolling, we just needed it to provide stability.”
James developed this method the first time Sunmount paved a speedway surface.
“Since we’d never paved a racetrack before, we talked to some people who did some racetrack work in the past and tried to do it their way,” said James. “We decided we could figure out a better method, so I came up with this technique and it really fits what we need to do.”
James also found that the type of roller used on raceway work makes a considerable difference.
“We purchased a new Bomag BW202ADH-2 for this job,” said James. It’s an 84-inch roller which is important because it allows us to make fewer passes. This is especially important on a racetrack because the fewer passes we make, the less the mat will tear up.”
Additionally, the BW20ADH-2 is designed for crab steering, which allows the operator to offset the rear drum up to 6.7 in. in either direction.
“The crabbing system really helps,” said James. “We crab so we don’t have the roller seams hitting on the same places as we’re rolling. With the six-inch crab, we can make a big 90-inch pass. We can also crab over to pinch a joint, which lets us compact the surface completely without the need for an additional roller.”
One other problem that Sunmount faced that was not directly related to the unique raceway resurfacing challenges was the weather. With forecasted high temperatures up to 106 degrees daily, working under the hot sun was not an option.
“We’re already working with hot asphalt and adding the excessive heat to the equation would be too much of a risk for our crew,” said James.
Thus, the decision was made to pave at night, beginning each morning at 2 a.m. and finishing at 1 p.m., to avoid the hottest portions of the day, yet still be able to contribute a full day’s work in order to stay on schedule, Fortunately, lighting was not a problem since the speedway has enough permanent illumination to cover 11 NFL-sized football stadiums and incorporates a unique system using mirrors to simulate daylight without glare or shadows.
Following the placement of two layers of asphalt on top of the open drainage layer, the resurfacing job was complete and ready to test.
“I drove my Expedition around the track at 80 miles per hour and could tell it was going to be a good one,” James said of the surface.
In early September, various Indy racers officially tested the track and confirmed James’ assessment. Apparently, Texas Motor Speedway officials also were pleased with the results.
“The new surface is excellent,” said an announcement written by Johnny Rutherford, head of special projects for the Indy Racing League. “It is so smooth, the competition should be even better than past Texas races.”
Although the learning curve involved in the Texas job presented a challenge, the results won Sunmount a second contract, this time to pave the parent company’s Atlanta Motor Speedway facility.
