Dr. Diandra: The concrete facts about Nashville Superspeedway

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Twenty-seven tracks host points-paying NASCAR Cup Series races in 2022. Only Nashville Superspeedway was designed with a concrete racing surface. Martinsville installed concrete in the turns in 1976, while Bristol and Dover transitioned from asphalt to concrete in 1992 and 1995, respectively.

The 1.33-mile Nashville track is a D-shaped oval and the longest of the four concrete-containing tracks. At 14 degrees of banking, it’s slightly more banked than Martinsville (12 degrees), but much less banked than Dover (24 degrees) or Bristol (24-28 degrees.) If we count half of Martinsville, concrete accounts for 13% of NASCAR Cup Series surfaces. Dirt makes up 3.7%, leaving asphalt to account for the other 83.3%.

Concrete vs. asphalt

Concrete and asphalt are both composites: aggregate (also known as “small rocks”) bonded together by a glue-like material called a binder. Concrete dates to the Roman Empire, while the first asphalt roads weren’t constructed until 1848. The nature of the binders explains the difference in timelines.

Pictures of asphalt and concrete to show how they differ

Concrete usually uses a portland cement binder, a mix of limestone and clay. Asphalt uses bitumen, a tarry black substance derived from the heaviest components of crude oil, as a binder. The binders determine the application method. While concrete is poured and cured, asphalt must be heated to a high temperature before extruding and being allowed to cool.

Because asphalt is more flexible than concrete, asphalt can be laid in long, continuous swaths. Concrete must be poured in sections to prevent damage from weather-induced expansion and contraction. The lines between concrete sections also assist with water drainage. That’s needed because concrete is less porous than asphalt.

Asphalt’s flexibility means it doesn’t spread out loads. Asphalt experiences larger, more concentrated stresses than concrete. The figure below shows typical stress distributions (in red) for asphalt and concrete.

A graphic showing how concrete and asphalt deal differently with stress. Concrete spreads stress out whereas asphalt doesn't

As you might guess — from this graphic or your own personal experience with potholes, asphalt is more easily damaged than concrete. Asphalt simply can’t stand up to the high forces of race cars taking tight curves at high speed.

Concrete costs

Transportation engineer Van Walling compiled the fascinating (as-of-yet-unpublished) compendium Oval Track Almanac. The three volumes document 45 years of extensive research of more than 1,000 tracks in the United States and abroad.

Martinsville, Walling explained, turned to concrete because race cars damaged the asphalt in the turns. Trucks can damage asphalt in expressway off-ramp loops the same way.

“Between high temperature and the force of the vehicles,” Walling said, “asphalt can be moved, creating a texture like a washboard.”

While “shoving“, as the phenomenon is called, is annoying for an off-ramp, those bumps create real trouble for race cars. Track operators have no option beyond frequent resurfacing or reconstruction — or switching to concrete.

That’s not to say that concrete tracks are impervious. In 2004, Jeff Gordon lost a Martinsville race due to concrete coming off the track. In 2018, a chunk of Dover’s concrete surface loosened and damaged Jaime McMurray’s car. Debris from the impact broke windows in a pedestrian crossover above the racing surface. That episode prompted Dale Earnhardt Jr. to tweet that “Asphalt is for racing. Concrete is for sidewalks.”

Walling, who has studied the original blueprints for Daytona International Speedway, said NASCAR founder Bill France Sr. wouldn’t necessarily agree.

“He intended the corners at Daytona to be concrete,” Walling said. “The problem was cost.”

Concrete requires a much greater up-front investment, and France was already struggling for funding.

“He initially planned a 60-foot racing surface,” Walling said, “but ended up settling for 40 feet.”

If France hadn’t found the money, Walling says, Daytona might have ended up as a much flatter track. Upfront cost is why almost all new tracks are built with asphalt, even though the upkeep is more expensive in the long run.

How concrete changes racing

The primary grip mechanism on any racetrack is the tire deforming around the aggregate. Concrete, by its nature, is smoother than asphalt. When NASCAR measured track surface roughness in 2019, Martinsville, Dover and Bristol were the three smoothest tracks.

The second grip mechanism is the adhesive interaction between rubber molecules on the track and on the tire. Although Goodyear designs their tires to lay down rubber on concrete tracks, the rubber doesn’t stay put.

“At speed,” Greg Stucker, Goodyear’s director of racing, said, “the track will progressively turn black as the cars lay rubber on the concrete surface and then turn back white under the caution flag as the tires pick back much of that rubber. Keeping pace with that transition is an important element of the race strategy.”

A driver loses traction on a concrete track much faster than on asphalt. Drivers have already spun more in 2022 with the Next Gen car than in all of 2021. The accident rate is also up.

Nashville’s concrete surface may pose a real challenge. Dover, the only 2022 race on a full concrete track so far, had 13 cautions. That’s almost double the number of cautions in each of the two races before, and triple each of the two before that.

One positive, through is that concrete doesn’t wear as fast as asphalt. Even though the car is new, the surface won’t have changed much since last year. The tires are also familiar. Teams ran the Nashville left-side tire three times (including at Dover) and the right side six times this year. They’ve even run the same left-right configuration twice: at Charlotte and the Texas All-Star Race.

Black and white

Track color matters.

The sun emits a spectrum of electromagnetic waves. The tiny band we can see is what we call light.  But the sun also provides infrared waves, like the heat lamps restaurants use to keep food hot. Its ultraviolet waves are why you should wear lots of sunblock at the track.

Different colored surfaces interact differently with the sun’s waves.

We see objects because they reflect, emit and/or transmit light. A red car absorbs all wavelengths of light except those corresponding to red. Only red wavelengths reach our eyes.

A graphic showing how white light (light of all colors) hits a red surface. The surface absorbs all the light except the red. That light is reflected to our eyes.

White surfaces reflect most wavelengths of light. That’s why you see concrete as white — white light is the sum of all colors of light. Black surfaces, on the other hand, absorb a lot of light. Because no light is reflected, you see black. The same thing happens with infrared waves, which cause black surfaces to heat faster than white surfaces.

A graphic comparing light hitting black and white surfaces

White tracks also reflect more light into the drivers’ eyes. Drivers will need tinted visor peel-offs for the 4 p.m. local (5 p.m. Eastern) start, which will be broadcast on NBC.

Heat causes the bitumen in asphalt to release oils that make the track more slippery. That doesn’t happen with concrete.

The end result is that a concrete track doesn’t change over the course of a race as much as an asphalt track. Nashville Superspeedway should be easier for crew chiefs to keep up with because temperature changes won’t change the racing surface as much.

On the negative side, if a team misses the setup, there’s much less likelihood that the track will come to them during the race.

Hailie Deegan to make Xfinity debut at Las Vegas

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Hailie Deegan announced Tuesday that she will make her Xfinity Series debut Oct. 15 Las Vegas Motor Speedway on NBC and Peacock.

The 21-year-old Deegan is in her second full-time season in the Camping World Truck Series. She finished a career-high sixth in that series last weekend at Talladega Superspeedway.

She will drive the No. 07 car for SS Green Light Racing with Jeff Lefcourt.

 

 

Alex Bowman to miss Charlotte Roval race

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Alex Bowman announced Tuesday night on social media that he will sit out this weekend’s Cup playoff race at the Charlotte Roval.

Bowman said on social media: “I am continuing to make strides in my recovery to make sure I can return to competition at 100%.”

This will be the second consecutive race he will have missed because of concussion-like symptoms after his crash at Texas Motor Speedway.

Noah Gragson will drive the No. 48 car this weekend for Bowman.

“Alex’s health is our first priority,” said Jeff Andrews, president and general manager of Hendrick Motorsports, in a statement. “We’re focused on supporting his recovery and seeing him back in his race car when the time is right. Alex has a long career ahead of him, so we will invest the necessary time and take our guidance from medical experts. We’re putting no pressure on him to return before he’s 100% ready.”

Bowman will be one of the four drivers eliminated from title contention Sunday.

Also Tuesday, Cody Ware announced that he will sit out this weekend’s Cup race at the Charlotte Roval, as he continues to recover from the ankle injury he suffered at Texas.

NASCAR Power Rankings: Chase Elliott leaps to the front

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A slick late-race move by Chase Elliott carried him to Victory Lane Sunday at Talladega Superspeedway — and back to the top of the NBC Sports NASCAR Power Rankings.

Elliott is the only driver with five victories this season. No one else in the playoffs has more than two (Tyler Reddick, eliminated from the championship hunt, has won three times).

Elliott, already qualified for the Round of 8 with his Talladega win, will be among the favorites in Sunday’s race at the Charlotte Motor Speedway Roval (2 p.m. ET, NBC).

Here’s how the rankings look approaching the end of the Round of 12:

NBC Sports NASCAR Power Rankings

1. Chase Elliott (No. 3 last week) — Elliott’s power move to win at Talladega was quite impressive and gave him four top-five finishes in the past 10 races. Clearly, he has re-established himself as the championship favorite.

2. Denny Hamlin (No. 1 last week) — Hamlin drops a spot despite a strong run (20 laps led and finishing fifth) at Talladega. Count him in the hunt for an elusive first championship.

3. Ryan Blaney (No. 8 last week) — Blaney simply will not go away despite continuing as the playoffs’ only winless driver (not including the Texas All-Star Race). He was victimized by Chase Elliott on Sunday at Talladega, finishing .046 seconds short of victory and a push into the next round.

4. Kyle Larson (No. 2 last week) — Superspeedway racing generally is not Larson’s strong point. He finished 18th Sunday despite leading eight laps and being in the front group much of the day.

5. Joey Logano (No. 4 last week) — Logano had an unusually poor performance at Talladega. He was involved in an early-race accident and struggled much of the rest of the day, finishing 27th.

MORE: Elliott celebrates, Logano laments

6. Ross Chastain (No. 7 last week) — Chastain tied Aric Almirola for most laps led (36) at Talladega and has been consistent as of late with three finishes of seventh or better in the past four races.

7. William Byron (No. 5 last week) — Byron’s worst news last week came off the track as he was penalized by NASCAR for dumping Denny Hamlin under caution at Texas. He finished 12th at Talladega.

8. Chase Briscoe (No. 9 last week) — Briscoe is quietly making the case that he could make the Round of 8 and challenge for the title.

MORE: Winners and losers at Talladega

9. Daniel Suarez (unranked last week) — Suarez maneuvered through the Talladega draft with style and came home eighth. He has three top 10s in the past seven races.

10. Christopher Bell (No. 6 last week) — Bell had a rough day at Talladega and will be looking to Sunday’s race at the Roval for redemption.

Dropped out: Tyler Reddick (No. 10 last week).

Talladega’s tale of two drivers: One celebrates, one laments

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TALLADEGA, Ala. — It’s dangerous to forecast what is going to happen next in these playoffs in a Cup season unlike any other. 

So keep that in mind, but Chase Elliott’s victory at Talladega moves him one step closer to returning to the championship race for a third consecutive season.

It’s easy to overlook that beyond earning a spot in the Round of 8 with his win Sunday, Elliott scored six playoff points. That gives him 46 playoff points. He has the opportunity to score seven more playoff points this weekend at the Charlotte Roval — an event he has won twice — before the next round begins.

Once the current round ends, the points will be reset to 4,000 for each of the remaining playoff drivers and they’ll have their playoff points added. 

At this point, Elliott would have a 21-point lead on his nearest competitor and a 31-point lead the first driver outside a transfer spot to the championship race.

The next round opens at Las Vegas, goes to Homestead and ends with Martinsville. 

A key for Elliott, though, is to avoid how he has started each of the first two rounds. A crash led to a 36th-place finish in the playoff opener at Darlington. He placed 32nd after a crash at Texas to begin this round.

The up-and-down nature of the playoffs, though, hasn’t taken a toll on the 2020 Cup champion.

“I feel like I’ve been doing this long enough now to understand the roller coaster that is racing,” said Elliott, who is advancing to the Round of 8 for the sixth consecutive season. “It’s going to roll on, right? You either learn to ride it during the good days, during the bad days, too, or you don’t. That’s just part of the deal.

“So, yeah, just try to ride the wave. Had a bad week last week, had a good week this week. Obviously great to move on into the next round, get six more bonus points. All those things are fantastic, we’re super proud of that.

“This deal can humble you. We can go to the Round of 8 and crash again like we did the first two rounds, or you can go in there and maybe have a really good first race. I don’t know. You show up prepared, do the best you can, figure it out from there.”

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Joey Logano has always been one who wants to race at the front in a superspeedway event instead of riding at the back.

When asked last month about the idea of Texas Motor Speedway being reconfigured to provide superspeedway-type racing — as Atlanta Motor Speedway was before this season — Logano questioned the value of that type of racing.

“Is that the type of racing fans want to see?” Logano said. “Because when you look at the way that people have finished up front in these superspeedways lately, (they) are the ones that are riding around in the back. 

“Do you believe that you should be rewarded for not working? Because that’s what they’re doing. They’re riding around in the back not working, not going up there to put a good race on. 

“They’re riding around in the back and capitalizing on other people’s misfortune for racing up front trying to win. I don’t think it’s right. That’s not racing. I can’t get behind that.”

Logano sought to race at the front as much as possible Sunday at Talladega, even after his car was damaged in an early incident, but he took a different tack on the final restart. He restarted 24th and dropped back, finishing 27th.

“We just wreck all the time, so we thought, ‘Boy, we’ve got a big points lead, let’s just be smart and don’t wreck and we’ll be able to get out of here with a top 10, assuming they would wreck because they always do,’” Logano said after the race. 

“That was the only time I’ve ever stayed in the back, ever, was today and they didn’t wreck. We gave up a bunch of our points lead. We’re still plus-18, which is a decent spot to be, but, the goal was to race for stage points and then drop to the back and wait for the crash. I hate racing that way. I’ve gotten beat many times from people that do that, then I tried it and it didn’t work.”

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Michael McDowell’s third-place finish continues his strong season. 

McDowell’s finish extended his career-high of top-10 finishes to 12. He has five finishes of 11th or better in the last seven races. 

“I’m proud of the season we’ve had and the run that we put together,” McDowell said. “Everyone did a great job on pit road executing and getting us track position when we needed it. It’s good to be there at the end and have a shot at it, just disappointed.”

Front Row Motorsports teammate Todd Gilliland finished seventh. 

“Race car drivers are greedy,” Gilliland said. “I wish I could have gotten a couple more there, but it was still a really good day. We ran up front most of the day and my car handled really well, so, overall, there are definitely a ton of positives to take out of this.”

Sunday marked the second time this season both Front Row Motorsports cars finished in the top 10. They also did it at the Indianapolis road course. 

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NASCAR confirms that the Hendrick Motorsports appeal of William Byron’s 25-point penalty from Texas will take place Thursday.

Should Hendrick lose that appeal, the team could then have a hearing before the Final Appeals Officer. That session would need to take place before Sunday’s elimination race at the Charlotte Roval (2 p.m. ET on NBC).

“Twenty-five points in the playoffs is a ton,” car owner Rick Hendrick said Sunday of Byron’s penalty. “I mean, in the regular season if you got a bunch of races, you can make it back up.

“I’ve seen other cars under caution hit each other. In that situation, (Byron) wasn’t trying to spin him, but they got a tower full of people, they could have put him in the back, could have done something right then rather than wait till Monday or Tuesday, then make a decision.”

Byron is 11 points below the cutline after Talladega.