Aged to perfection

Crews repave Texas Motor Speedway the right way

Asphalt Pavers Article June 06, 2017
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Crews repave Texas Motor Speedway the right way

Having a ticket for some dry cleanings can lead to a lot of watching and waiting. Nobody would blame anyone if they walked out.

 

Many paying spectators were exiting early during races at the Texas Motor Speedway due to wet conditions. No matter how hard crews worked to dry the track, it usually took up to four hours before the pavement was safe for racers.

 

“The track, on top of being old and deteriorated . . . the fines would come to the surface and there was a lot of water that was retained in the track,” Stephen Swift, vice president of operations and development for Speedway Motorsports, told Roads & Bridges. “The fines caused degregation, and the process we used to dry the track exaggerated that. You get movement in the fines, and once that happens the surface acts like a big sponge.”

 

“It would take time to dry after a rain, which means T.V. time,” John Rauer, senior plant manager for Lane Construction, which was the prime contractor on the Texas Speedway job, told Roads & Bridges. “People would leave the seats and they would not come back.”

 

Paving was handled by a Vogele MT 3000 2i Offset PowerFeeder and an Ingersoll Rand Titan paver. A Link-Belt RTC 8110 crane was used to keep the machines in place.

Paving was handled by a Vogele MT 3000 2i Offset PowerFeeder and an Ingersoll Rand Titan paver. A Link-Belt RTC 8110 crane was used to keep the machines in place. 

 

Banking on less

As with any entertainment venue, the Texas Motor Speedway wants to create the emotional adhesive that keeps people in the stands, which made the paving project—the first one on the track since 2001—more than just about drainage. To add more excitement, a decision was made to reduce the embankment—from 24° to 20°—in turns 1 and 2.

 

“We knew we had to redo the track and we knew we had to do something, and we wanted to change the racing and put it back in the driver’s hands where the drivers had to decide,” said Swift.

 

After breaking up the pavement in turns 1 and 2, backfill was brought in, about 4.5 ft worth, and placed at the flat line, which is at the bottom of the track. Turns 1 and 2 also were widened, and the first lift consisted of 2 in. of a No. 57 stone, which is called a Type B in Texas. Next came the actual paving, which was handled by a Vogele MT 3000 2i Offset PowerFeeder and an Ingersoll Rand Titan paver, which laid down an 18-ft-wide mat around the track. Crews used a Link Belt RTC 8110 crane to keep the machines in place. An asphalt base layer followed the sub-base in turns 1 and 2. The mix contained a PG 64-22 binder and was about 300°F at laydown. A Bomag 202DB steel double-drum roller handled all compaction duties on the job. A Stansteel asphalt plant located about three miles from the track produced the mix at about 310-320°F. The plant was originally a batch plant before it was converted to a drum plant, and for this job asphalt was being cranked out at 130 tons per hour. Testing at the plant was being done every 500 tons, or as needed.

 

An open-graded asphalt drainage layer (OGDL) was applied around the whole track to help with drainage. So for turns 3 and 4 and the two straightaways, Lane used the existing track as a base for the new pavement. The OGDL was 2 in. thick, contained a PG 76-22 binder and had about 1.2% asphalt content. The rock size range was No. 67 stone mixed with No. 57 stone. It took about three passes with the Bomag roller to achieve the desired density.

 

The surface layer carried a PG 82-22 binder which was mixed in with 3⁄8-in. minus rock, ¼-in. minus rock and manufactured sand. Air voids were 6% and the asphalt content was plus 6%. The Bomag roller was making four passes—two in static mode and two in vibratory mode—to achieve 94-96% density. It would make an extra pass on cooler days. Lane used a Troxler nuclear gauge to test for density, which was done 100-200 ft behind the roller.

 

A Komatsu D61EX crawler tractor was used in the paving process on the Texas Motor Speedway.

A Komatsu D61EX crawler tractor was used in the paving process on the Texas Motor Speedway.

 

The under drain, a 6-in. perforated pipe backfilled with No. 57 stone, runs around the toe of the track.

 

Brand new pavement is not a good look for racecar drivers. Rubber is needed on the track to encourage passing. The last thing track owners want is single-file racing. In the past, new tracks took some time to mature. The Texas Motor Speedway, however, wanted to age the pavement before the first race. When paving was complete, a liquid lime slurry was applied with brooms. The liquid lime hardens the surface naturally and strips some of the liquid asphalt off the aggregate to take away some of the grit so that the track does not have that “new” feel to it. Those at the Texas Motor Speedway took it a step further. Crews used a machine that turns tires in reverse as a tractor is moving forward. It’s basically a constant burnout, which leaves a layer of rubber on the track.

 

“If you could imagine a box plate that goes on the back of the tractor, but it is taller and has four tires on it,” explained Swift. “Those tires are driven by an actual racing rear end that is tied into the PTO.”

 

The machine used in Texas was a modified version of the original, which required a clear, hot day.

 

“On the one we built we changed the gear ratio up a little bit where it spins a little different, and added some weight to it to get more down force like what the cars create,” Swift said.

 

Texas Motor Speedway went through 120 tires to get the new track right, and that included going out a second time after the first day of racing.

 

To help with drainage an open-graded drainage layer was placed over the entire track.

To help with drainage an open-graded drainage layer was placed over the entire track.

 

Done early and done right

The construction schedule put the pinch on the entire process. The final race of the 2016 season was in November, and the decision to redo the track came in December. Construction started Jan. 8, but the paving did not begin until Feb. 4, with the first NASCAR event looming on April 9. Crews worked 13- to 14-hour days and finished 2 1⁄2 weeks early. The weather also cooperated, as February and March were milder than normal in Texas.

 

The first race of the season, a NASCAR Monster Truck Series, went very well, and the drivers enjoyed the track.

 

“The drivers were really surprised how we had created that older racetrack on the surface,” said Swift. “They liked the new layout. They said it made it challenging, but yet it was driveable.”

 

“I think everybody was happy,” remarked Rauer. “They tried to mix it up a little bit and I think they accomplished what they set out to do by changing the banking in turns 1 and 2 and leaving it the same in 3 and 4.”

 

About the author: 
Wilson is editorial director of Roads & Bridges.
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