Sunland Asphalt performs mill and fill on Miami Formula 1 track with echelon paving ahead of successful Grand Prix

In the Formula 1 world, millimeters matter in both racing and paving. Management at Sunland Asphalt & Construction, Littleton, Colorado, knew they would need their A team on hand to handle the 2023 resurfacing project at the Miami International Autodrome, home of the Formula 1 Miami Grand Prix. They mobilized 75 internal employees, 15 technical specialists and 40 pieces of heavy equipment from around the country on 35 separate transport loads.

The project’s scope consisted of milling 2 inches of the existing track and repaving it with a highly specialized asphalt mix designed to Formula 1 standards. Crews were to repave the track at 2 inches thick for a total of 9,500 tons over an eight-day period.

Construction scheduling for the 3.36-mile anticlockwise circuit, which winds around the Hard Rock Stadium in Miami Gardens, had to be choreographed around the stadium’s other events, including the end of the National Football League season, a jazz music festival and the Miami Open tennis tournament. The International Automobile Federation also required Sunland to have the mix put down 60 days before its big event for the material to properly cure.

Needless to say, it took a lot of coordination for Sunland to make this happen and the Wirtgen Group was just one of the many partners in place to help.

Sunland crews used three pavers working in echelon to prevent cold joints along the 50-foot-wide track, paving at a very efficient pace of only 6 fpm.

Step 1. Mill. The crew from Sunland Asphalt & Construction, Littleton, Colorado, used three milling machines to precisely remove 2 inches from the existing track.

The Need for Speed—and Grip

In 2022, Miami held its first Grand Prix event on the track. When drivers expressed concerns with the grip on the pavement, track owners decided to lay fresh asphalt ahead of the 2023 race. The track management hired Tilke Engineers & Architects, headquartered in Aachen, Germany, to oversee track resurfacing, which they said would ultimately improve the “spectacle” of the 2023 race.

Sunland was hired to complete the mill-and-resurface of the track and began work to remove the existing surface in the early spring of 2023.

Sunland Asphalt trucked all their equipment in to ensure crews were familiar and comfortable with their equipment and processes. They used three pavers working in echelon to prevent cold joints along the 50-foot-wide track. The pavers were also moving at a very efficient pace of only 6 fpm to ensure paving smoothness.

The mix design for the track included 60% US-mined granite from Georgia with the remainder of the aggregates being locally sourced lime rock from Southern Florida. These aggregates ensured the grip needed on the course.

Step 2. Fill. Three pavers worked in echelon at a steady pace of 6 feet per minute to ensure no cold joints interrupted a smooth mat. Here you can see a Weiler material transfer vehicle feeding the hopper insert of one of two Vogele Super 2000-3i pavers to assist in smooth, constant material control.

Technology Meets Tight Tolerances

In addition to the three Wirtgen mills, Sunland used three HAMM HD+ 80i rollers and two VOGELE Super 2000-3i asphalt pavers. The Wirtgen Group technology on these machines is “plug and play,” which allowed the team at Sunland to get up and running with these machines easily.

“The plug and play feature on all these machines has been a huge advantage to us as a Topcon provider, making the installs quick and easy,” Tony Carden, intelligent paving product manager at RDO Equipment said. “We’re also able to provide serviceability for them both on the dealer side and from the manufacturer side. It’s a win-win.”

The project’s scope consisted of milling 2 inches of the existing track, then repaving 2 inches thick with a highly specialized asphalt mix designed to Formula 1 standards, for a total of 9,500 tons over an eight-day period.

Thermal Imaging

The pavers on the job were equipped with a temperature monitoring system. Thermal cameras were mounted to the pavers and used to find any temperature differences that could indicate potential segregation in the mat as it was being laid.

“The thermal profiling that we’re using on the pavers gives a rundown of where the pavers were, where they’re going, at what speed they are running and at what temperature,” Greg Hughes, project engineer at Sunland said. “If one isn’t getting to a high enough temperature, we can go back and look at it and see what happened and fix it and that’s a great tool for us.”

To address racecar drivers’ concerns about pavement grip, the Miami International Autodrome’s Formula 1 Miami Grand Prix track was milled and resurfaced ahead of the 2023 big event. All photos courtesy of C2C Visuals

Intelligent Compaction

“The intelligent compaction on all the rollers shows us our roller patterns throughout the day,” Hughes said. “It provides us real-time documentation of the areas we are hitting and if we’re hitting any areas more than we should. We’re also able to know if we should be vibrating more or less as well.”

With the HAMM Intelligent Compaction system, users can set a designated number of passes ahead of paving. The system shows the operator, on the in-cab display, how many passes have been completed.

Sunland management says they also use the intelligent compaction system as a training tool. “We sit with our roller operators, and we can show them where we might be able to improve on future jobs.”—Greg Hughes

Step 3. Compact. The compaction team set a rolling pattern behind the pavers to achieve optimum densities and a smooth driving surface incorporating three HAMM HD+ 80i rollers.

Sunland management says they also use the intelligent compaction system as a training tool.

“We use it in the office to see where we could be more effective,” Hughes said. “We sit with our roller operators, and we can show them where we might be able to improve on future jobs.”

The crews finished paving the 19 turns of the course on the Autodrome’s schedule, and the 2023 Miami Grand Prix was a success thanks to the hard work and dedication of the people behind the machines.

Balancing GTR, RAP, WMA over failing concrete proves successful for Missouri taxpayers

Early June 2023, the team at NB West Contracting, headquartered in Pacific, Missouri, began work on a complex overlay. The main goal was to cover up a 15.3-lane-mile, potholed, concrete section of Route 63 in Maries County and make it a smooth, safe driving surface for the taxpayers. The Missouri Department of Transportation (MoDOT), Ingevity, National Center for Asphalt Technology (NCAT) and NB West partnered to exceed that goal.

Steve Jackson, the vice president of asphalt plant operations and sustainability for NB West spoke of combining ground tire rubber (GTR) and 20% recycled asphalt pavement (RAP) as one aspect of the warm-mix asphalt (WMA) project.

Jackson took infrared images of the project to double-check consistency of mat temperatures and confirmed that consistency coming from the plant to the jobsite.

“It was a balanced mix design, performance spec, SP095C (9.5-millimeter,) Superpave with ground tire rubber and RAP, warm mix, placed through a spray paver, and bonding to a concrete pavement,” he said. He listed off all those moving parts of the project like it was business-as-usual for the production and paving personnel. For a team that’s been on the scene since 1956, it almost is a walk in the park, yet they pulled out the quality control/quality assurance (QC/QA) and safety best practices to make sure everything flowed smoothly for an award-worthy project. In the end, they garnered the Missouri Asphalt Pavement Association (MAPA) 2023 award for a primary route under 50,000 tons. Here’s how they accomplished it.

Familiar Parameters

In 2012, NB West had successfully performed a project bonding an asphalt layer to concrete with the company’s Roadtec spray paver, and saw an opportunity to apply that technology again. Jackson explained the DOT originally was letting the project with the 19.0 mm mix and a 12.5 mm mix for the surface layer, but his team wasn’t excited about that because both layers would have been placed at less than four times the nominal maximum aggregate size.

“The thickness of the layer didn’t allow for the 12.5 mm to work smoothly,” he said. “In 2012, we’d done something similar bonding concrete with the spray paver, so after we were awarded the [Maries County] job, we did a value engineering proposal to bond to the concrete. We suggested two lifts of 9.5 mm Superpave with an overall reduction of 1 inch in the overlay. We’ve been trying to get back to realistic lift thicknesses that can get good compaction and DOT agreed with that.

The Relationship Between EPDs, BMD, RAP & Plastic

“We also proposed using ground tire rubber to delay the cracking coming back through the mix. The other reason for the GTR is we were doing our performance tests, and when we’re using the GTR in those mixes, our IDEAL-CT numbers have just been off the charts. Our performance tests are the IDEAL-CT and the IDEAL-RT.”

Good Numbers: For the Maries County project, the team saw an average CT-Index of 168, an average RT-Index of 77 and Hamburg rutting result of 7.0 mm.

The unconfined joints were on the outer edge of a concrete roadway that had a rock shoulder. The NB West crew paved the mainline and used a non-Superpave asphalt layer over the rock to cover up the shoulder.

Making Mix

Jackson credits the elasticity of the GTR for aiding in pavement performance. “We’re putting the ingredients back in that gives it a little flexibility.”

To add the GTR, NB West uses the dry process, adding Elastiko® engineered crumb rubber asphalt (ECR) manufactured by Envirotx and supplied by Asphalt Plus. N.B. West’s Joe Schroer, P.E., materials and support engineer, explained the dry process is considered mixture modification. Performance testing measures the interaction of GTR, aggregates and binder as a system, and allows a more innovative approach to designing asphalt mixtures, he shared. Additional enhancements to mixture performance can be made by adjusting the grade of the binder.

A groundman brings the 2,000-pound tote of Elastiko material to the feed bin of a modified Hi-Tech Fiber machine with a forklift. From the bin, the machine feeds the material to a 6-inch-diameter flexible hose and to the portable Astec Double Barrel.

Balance Your Mix Design for Asphalt

“We blow it right into the drum,” Jackson explained. “The control unit’s inside the control house and it’s tied into the tons per hour you’re producing.” In this manner, the plant controls the addition of the GTR product as it would cellulose fibers being fed in.

This project ended up with a variety of additives in the production process, but Jackson said it was business as usual for the team. “We had the normal challenges. This still had our normal Superpave testing in it; we were still running volumetric testing and adding in the performance testing. So, it was a lot of testing.”

Jackson shared a testing tip for working with GTR. “When you’re making pucks up, if you put a weight on your mold top (with the GTR in there), it keeps the GTR from rebounding while cooling. If you don’t do that, you get some kinda strange results.”

The unconfined joints were on the outer edge of a concrete roadway that had a rock shoulder. The NB West crew paved the mainline and used a non-Superpave asphalt layer over the rock to cover up the shoulder.

Smooth Quality

In the field, the crew worked with temperatures below 300 degrees F. Even with the Evotherm WMA additive in play, they elected to have temperatures closer to HMA to accommodate the Elastiko. “The manufacturer told us not to go below 280 with the GTR,” Jackson said. “We went down to 270 and didn’t have any problems.” A longer haul—approximately 40 minutes from the plant—for this project allowed a longer dwell time for interaction of the GTR with the binder at the reduced temperature, according to Schroer.

Jackson took infrared images of the project to double-check consistency of mat temperatures and confirmed that consistency coming from the plant to the jobsite. “I took my FLIR camera out there…the good thing is I think the ground tire rubber holds the heat in the mixes. It was about 40 minutes to the job, and we were on a two-lane road where we had to flag the traffic, so it was challenging getting the trucks in and out. But we didn’t lose a lot of heat in the mixes.”

One of the best practices Jackson recommended was staying on top of the rolling pattern. “We were keeping our rollers right up on the screed. Because we were already dropping our temps below 300.”

The mix design used all the moving parts. “We used 20% RAP in this mix and 10% by weight of AC was the asphalt plus Elastiko product. The idea was that we had our baseline AC, which was a 64-22 and 10% of the Elastiko was in there to bump it up to a 76-22. It was the same mix on both lifts.”

Is Your Lab Ready for Balanced Mix Design?

The Missouri DOT allows whatever percentage of RAP the contractor wishes to use and still meet performance specs. “Technically, there’s no limit,” Jackson said. “Our problem is availability. We can’t run maximum RAP in our mixes because we don’t have it. There was nothing to mill on this project, so we had to bring RAP from other locations to put in this mix.”

For the NB West team, that’s just one more solvable problem. Jackson spoke of the “can do” willingness to put a puzzle together when it comes to the crew, starting with Plant Operator Clay Pitts.

“Number One is just the general attitude of not saying ‘we can’t do that.’ Yeah, we’ll try that. That’s huge. Clay’s great about that. Always willing to try something new and make it work.

“Dustin Hollis was the foreman and Juan Marquez was the general superintendent; they manage several jobs at a time.”

Jackson also described the effort the quality control/quality assurance (QC/QA) team had to put forth, given the changes to the contract after it was bid.

“Our quality control dept came up with these mixes and tried new things and really kind of pushed the envelope. The performance testing, the way we did this, that wasn’t set up in the contract, so we still had to do all the volumetrics testing and add the performance on top in a BMD situation. We’ve never run this mix so we were going live on the road with what looked in the lab like it would run well and do its performance testing. We had to go behind the spray paver and dig a sample behind the screed in a mat that has a polymer in it. It was a monumental challenge for our QC team.

“We have our plant people and our QC people coming up with this crazy stuff and then we go execute it and we still have to make money at it. I think we did a slight tweak to the mix after the first day or two to take advantage of the performance test because we could reduce our air voids using the performance test.”

The final result gave an average international roughness index (IRI) of 32.

“On concrete pavement that they didn’t have enough pavement repairs for, to come out like that, I think it was great,” Jackson said.

Not only did the project win a MAPA award, the traveling public noticed the good work. Jackson has received unsolicited comments about the work. “I’ve had somebody call and say, ‘that rides real good.’ People see that [kind of result] and they’re more likely to support the gas tax.”

Balancing Mix for Optimum Density

One of the reasons NB West uses a warm-mix additive in every mix they can is to get the compaction aid assistance.

“We run Evotherm in every mix that we have to get density on,” Jackson said. “We don’t run it on Novachip, but every other mix, we’re putting it in there.”

One of the factors that changes when developing a balanced mix design (BMD) and doing your performance testing is the number of gyrations.

“You’re dropping your gyrations,” Jackson said. “You’re making a mix that’s got more AC in it. So, you can take advantage of some of those mixes then of making them more compactible in the lab so when you go to the field, it’s easier to get compaction.”

Take a typical interstate mix as an example.

“We started off at 125 gyrations on interstate mixes. When you’re trying to compact that, you’re breaking rock trying to get density. Then we backed off to 100 gyrations, then to 80. I think we’re at 60 with BMD.

“To keep your voids in mineral aggregate (VMA), you end up putting some more AC in it. So, you have a mix that will compact, and it’s got binder to hold it together. Now instead of breaking rock to get to 92%, you’re rolling this and getting 96%. That’s what FHWA wanted: higher density. We get higher density by going to balanced mix design.”

Learn More

Step 1: The forklift brings the tote of ground tire rubber product to the bin.

Step 2: The GTR product is fed through the 6-inch-diameter, flexible hose.

Step 3: The plant’s controls meter the product just as it would any cellulose fiber being fed to the Astec Double Barrel drum.

Established in 1954 with the purchase of a limestone quarry in Cobleskill, New York, Cobleskill Stone Products Inc. has grown into an aggregate producer, material supplier and construction services provider for upstate New York. When it comes to asphalt paving jobs, a large portion of the company’s business revolves around overlays for states, counties and municipalities. Recently, the firm used a Dynapac MF2500CS mobile feeder to help pave two rehabilitated stretches of I-88—one near Schenevus, and the other near Central Bridge.

“Continuous paving also eliminated bumps in the mat from the machine stopping and letting the screed settle, which resulted in a more consistent and higher quality finished product.”—Sam Galasso

Minnesota Contractor Improves Efficiencies and Productivity with Asphalt Milling Tool

Multiple Lifts, Smooth Results

“The Central Bridge project included three lifts of blacktop to put down,” explained Michael Moore, vice president of Cobleskill Stone Products. Those were a base, binder and top course.

“The job specs only required using a material transfer vehicle (MTV) for the binder and top course, but we chose to use one for all three courses,” added Dan Mark, the project superintendent on the Central Bridge project.

Mark explained that using an MTV allowed the crew to eliminate truck transitions, lay more tons at a consistent speed, and provide “better rideability.”

With a Dynapac MF2500CS mobile feeder, an operator transfers asphalt from a truck to a paver at Cobleskill Stone Products’ I-88 rehabilitation job in upstate New York.

Job specifications for the MTV included a 30-tonnage capacity between the MTV and the hopper.

“We looked at multiple brands before choosing the Dynapac MF2500,” Moore said. “Using a tracked machine opposed to a wheeled machine had specific appeal because we were working with crack and seat material. Once we established the carrying capacity met the job specs, we looked at the remix capabilities built into the machine and the oscillating conveyor, and it was clear the machine fit the bill for how we wanted to approach the project.”

How to Patch with Infrared Tech

The Dynapac MF2500CS mobile feeder has a maximum operating speed of 82 feet per minute and a feed capacity of 2,000 tons per hour, when using an optional swing conveyor, or a feed capacity of 4,000 tons per hour with a standard conveyor.

At the I-88 Schenevus project, Cobleskill Stone Products’ operators typically laid 17 feet of asphalt per minute, totaling upwards of 3,000 tons of material per day, which allowed them to complete echelon paving with two pavers running side-by-side for a portion of the project.

From left to right, Cobleskill Stone Products Inc.’s Sam Galasso, Michael Moore and Dan Mark; Tom Kiselica, paver and feeder marketing developer at Dynapac; Mike Moore Jr., quality control manager at Cobleskill Stone Products; and Steve Kenney, sales representative at Anderson Equipment Company, work together.

“One of the days, we were able to lay almost 3,400 tons of material,” noted Sam Galasso, supervisor. “The MF2500 helped tremendously with production and eliminated the cold joint in the center of the mat. Continuous paving also eliminated bumps in the mat from the machine stopping and letting the screed settle, which resulted in a more consistent and higher quality finished product.”

“Machine uptime for the I-88 project was 100%,” Moore said. “The user-friendly interface made it easy to operate and allowed our operator to train other employees to run the machine.”

Dealer Support

When looking for the right machine for the I-88 project, Cobleskill Stone Products turned to Steve Kenney, a sales representative at Anderson Equipment Company, and Tom Kiselica, the paver and feeder marketing developer at Dynapac.

“The machine was fit for this job site,” Kenney said. “The controls are directly in front of the operator, who can operate the machine from either side of the cab.”

Cobleskill Stone Products also relies on Anderson Equipment Company and Dynapac for support.

“Both Tom and Steve have been excellent,” Moore said. “They checked in on the job’s progress and machine’s performance multiple times. We’ve worked with them before and know that they go above and beyond to make sure our Dynapac equipment is running.”

Hopper inserts can be helpful to increase the volume of asphalt material you can carry, but they can also assist in avoiding segregation of your asphalt mix. That’s the idea behind the passive remixing insert with an active remixing module from the team at Vögele, a division of Wirtgen America, Antioch, Tennessee. Here’s how it works.

With the use of a material transfer vehicle, asphalt mix is delivered to the hopper insert. It can be loaded between two baffles located within the insert, which limit gradation segregation. The maximum capacity of the insert, when filled only between the baffles, is 17 tons. However, operators can also overflow the baffles, as the company literature states, to make use of the full 23-ton hopper.

“Anytime you create a pile, you allow larger stones to roll on the sloping face until they stop, and they stop when they hit the wall of the insert,” said Laikram “Nars” Narsingh, manager, commercial support and development for Vögele. “The baffles allow material to funnel straight into the flight chain to prevent larger stones from rolling to the sides.”

Between the baffles, there is a grate system to break up cold crusts as they enter the insert. This combats not only gradation segregation, but also thermal segregation by allowing smaller clumps to absorb heat from the hotter surrounding mix.

The grate system is located more than a foot beneath the top of the baffles to allow operators to pile asphalt on top of the grate so that the increased weight forces the material through the parallel grate bars, which are spaced between 3 and 8 inches apart.

After passing through the grate, the mix travels down to the base of the hopper insert. Since the front of the insert is wider, material flows from the front of the insert to the back of the insert to minimize thermal segregation. This wider, overhanging front of the insert also expands its total capacity.

The material then passes through the trapezoid-shaped opening on the bottom of the insert, which also aims to reblend mix naturally as stones move along the sides of the insert, and is then discharged onto the conveyor of the asphalt paver.

For more information, contact Narsingh at (615) 501-0600.

To decrease the number of machines each operator has to track, and to provide even operation of those machines, the engineering team at Roadtec, Chattanooga, developed the new Shuttle Buggy Autotracking Package. It uses wireless technology to get smooth material transfer while the paver sets a pace that the MTV matches. Here’s how it works:

First, the paver operator turns the system on or off by pressing a button on the paver pendant at his platform. This sends a wireless signal to the autotracking sensor, which is mounted or hung near the discharge chute of the material transfer vehicle (MTV) and the paver.

The autotracking sensor is mounted aboard the C3 conveyor and monitors the distance to the hopper target. (An optional, second sensor can monitor the pile height within the hopper.) The hopper should be fixed with a smooth, flat surface for the sensor to use as a reference point to send and receive distance signals. If you don’t have a flat surface, weld a small piece of metal to the hopper’s exterior. As the autotracking sensor monitors distance, it zings a wireless signal to the shuttle buggy operator to let him know that the equipment’s speed is—or is not—matching that of the paver.

If the MTV needs to slow down, the autotracking sensor provides that information to the operator. The amber and red lights at the top portion of the two cylindrical towers on the paver operator’s station will light up to indicate the shuttle buggy is slowing down. If the shuttle buggy needs to speed up, the amber and red lights at the bottom portion of the two cylindrical towers will light up to indicate the increase in speed. When the green lights in the center of the towers are illuminated, the operators can rest assured that the shuttle buggy is at an acceptable distance from the paver—moving at the same speed.

If the operator needs to adjust the discharge conveyor to hit the hopper target, he can press the appropriate button on the paver pendant to signal the conveyor to move to the right or left.

For more information, contact Roadtec at (423) 265-0600 or visit www.roadtec.com.