In 2016, the Russellville School District in Arkansas awarded a large contract to reroof its middle school facility. As part of the project, the general contractor took 120 tons of shingles off the roof in late December, and wisely partnered with a local roadbuilding contractor that kept the material for future use.

“There was some unusual stuff going on here, and that’s part of what makes this interesting,” Bob Hiegel said. He’s the proprietor of Bob Hiegel, Architect, of Russellville, Arkansas, which is the go-to design firm for much of the Russellville School District work. “This is only the third or fourth project for the school district that involved asphalt. It was just over 210,000 square feet of roofing shingles that were torn off and replaced with a metal roof. It was an example of roadbuilders and roofers getting together to help an owner save some money. The savings were in the neighborhood of $40,000 on the dumping fees alone.”

In June 2017, Blackstone Construction was the low bidder and awarded the contract to repave the Center Valley and London elementary schools within the Russellville School District. July 24 through 28, Blackstone’s two paving crews mobilized to taper-mill some areas and overlay the parking lots using the recycled asphalt shingles (RAS) from the middle school in the environmentally friendly asphalt mix.

“We ground up those shingles for their parking lots,” Paul Mlakar said. He’s the general manager for Blackstone and shared that not only was the process “green,” the shingles were, too. “The shingles from the school’s roof were literally colored green, so we could actually see them going into the mix.”

Blackstone management purchased two RAS bins from Astec—one for each plant—late in the winter of 2016 to get them up and running for the 2017 paving season. Mlakar explained the Astec bins are specifically designed to weigh and convey the light-weight shingle material. The Astec RAS bin has four load cells that measure weight depletion and integrate the measurement into the controls and production process.

While that’s pretty cool, there was more to shingle stockpiling than keeping the colors separated. “In general, we receive shingles and produce a weigh ticket recording each load,” Mlakar explained. “As part of my air permitting compliance, I require the roofer to independently test and certify the shingles as asbestos-free. I keep a ‘certified’ pile separate from the receiving pile so it was easy to separate the school’s shingles. We did get indications from the school district in the spring of 2017 they intended to put some parking lots out for bid in the summer, so early on in the process, we had the vision we could actually grind their shingles, which would give us a cost advantage, and put them back into their own parking lots.”

Mlakar gave the breakdown of materials: “We received about 120 tons of shingles from the district’s roof project. We produced about 900 tons of hot mix for Center Valley and about 400 tons for London Elementary. We ran 20 percent RAP and about 1 to 2 percent shingles. So we put about 20 tons of shingles into the mix. That’s 20 tons of shingles that didn’t go to the landfill.”

“This was the first time the school used that recycle,” Hiegel said. “It was not mandated. We wrote the bid as recycled was encouraged. They [Blackstone] still had to be the low bidder to get the job.”

The Russellville School District stays on top of new things. First of all, Morgan Barrett of the civil engineering and consulting firm Barrett & Associates, also of Russellville, is on the school board. Hiegel explained that Barrett didn’t want to be paid for his work, so Barrett merely coached and advised the architect and contractor on the mix design that would incorporate RAP and RAS. Blackstone made the mix design. Specifically, Jackson Beehrle, the lab tech for Blackstone, made the mix design.

Mlakar described him as a super young man. “He walked in as a green 20-year-old,” Mlakar said. “I noticed he had a great attitude, and I picked him off the crew to put him in the plant. We threw him in drinking from a fire hose.”

Beehrle got his certificates and became a skilled lab tech as well as a backup plant operator for Blackstone. When the Russellville School District project came up, he was ready for the challenge.

“We hit him with a tight window on this project, but he’s one of those guys who will come in early and stay late,” Mlakar said of Beehrle. “He’s a responsible young man. He did an excellent job of delivering the new mix design on a short timeline. Without his efforts, we wouldn’t have produced the product.”

Professional Paving

Paul Mlakar shared: “Our new plant has the Astec Double Barrel extended drum capable of 40 percent RAP. We think recycling is not only good for the environment, but also a way for us to achieve a sustained competitive advantage.”
Caption for image saved as 7300 Bins OperationThe Blackstone crew keeps material separated cleanly for optimum quality control.

With mix design in hand, Blackstone crew members were ready to begin. Hiegel explained that they decided to break the project into two parts due to the timing. Both school parking lots had to be completed before the start of fall 2017 classes, of course.

The Center Valley Elementary School parking lot renovations included 840 square yards of perimeter milling, 400 linear feet of trench repair, a couple concrete slabs, some backfill and grading, 10 tons of asphalt leveling course, and 830 tons of Type 2 asphalt. The London Elementary School parking lot renovations included 996 square yards of perimeter milling, 54 linear feet of trench repair, a couple concrete slabs, 3 tons of asphalt leveling course, 435 tons of Type 2 asphalt and additional asphalt for a walking trail. “One crew could easily have handled it, but because of time constraints, we split it up,” Mlakar said.

For the majority of the Center Valley portion, Foreman Gary Foshee’s crew took care of business.

“He’s done it all,” Mlakar said of Foshee. “He’s a longtime industry guy who’s been here since the company started. He’s worked the plant, the lab, the paving crew. If you cut him, he’ll bleed asphalt. He stays after it. He’s our interstate, high-production guy.” For the majority of the London portion, Foreman Tim Koffman’s crew handled the details.

“He has about six years total with the company,” Mlakar said of Koffman. “He had his own small paving business. We approached him when we got to the right size and brought him on board. He’s got a real good knack for your parking lot and commercial work.” The two foremen head up the crews that can handle different “types” of work for Blackstone’s paving business. Mlakar said he can put Foshee’s crew on state or heavy highway projects, and Koffman’s crew on commercial and residential projects because they’re talented paving professionals with specialized skill sets. But he also feels comfortable switching them back and forth when needed, as the most recent Russellville School District project proved.

Planning Ahead

It took the whole team to bring the sustainable project together. As mentioned above, Mlakar takes care with the shingles coming into his operation. His team uses a Doppstadt AK 230 grinder, which he described as “a smaller machine” from a German manufacturer. The smaller machine required less capital investment up front, is portable and gives Blackstone room to grow. He only grinds shingles as they’re needed to minimize issues of agglomeration and moisture buildup.

“Our DOT only allows manufactured shingle waste in their mixes, so the only opportunity for me to use our shingles is in private mixes,” Mlakar shared. “We purchased two RAS bins from Astec—one for each plant—late last winter. We installed and certified the bins this spring in preparation for this paving season. The Astec bins are specifically designed to accurately weigh/convey the shingles. Historically, the shingles are so light and are conveyed at such a small percentage—slow speed—that it’s hard to use a conventional volumetric feeder bin and maintain proper accuracy. The Astec RAS bin has four load cells that measure weight depletion integrating this into the controls and the production process. The preliminary results are good. We did have to do some de-bugging and trouble-shooting, but once we cleared those hurdles, it appears to work well. The accuracy is consistent.”

The decision to add RAS bins and increase RAS use is a strategic one. Mlakar explained that even though the price of oil has been relatively flat in 2017, thus the payback has been slow; he knows the price of a barrel will go back up. Mlakar also considers the optimism he sees in the industry and politically. For example, Gov. William Asa Hutchinson II (R-Ark) recently re-allocated funds to match money from the Federal government.

“We’re hedging off optimism,” Mlakar said. “Our company made a strategic move last winter and the RAS bins are just a part of the direction we’re headed. In addition to the new RAS bins, we purchased two new Astec RAP bins and our new plant has the Astec Double Barrel extended drum capable of 40 percent RAP. We think recycling is not only good for the environment, but also a way for us to achieve a sustained competitive advantage. By engaging in this long-term strategy and vision, less material is hauled to the landfill, we buy less AC, we consume fewer hydrocarbons, and ultimately we gain an advantage at the bid table. It’s the proverbial win-win. To me it’s proof that industry can co-exist with the environment. It doesn’t have to be a zero sum game. We just have to commit to work together.”

Another aspect to this “early” commitment is educating employees. Mlakar pointed out that with any new technology or new equipment, there’s a learning curve. “We’re getting our ducks in a row now,” he said. “It may be two or five years [before everyone else is investing in RAS again], but let’s get the learning curve out of the way, and under our own timeline.”

The Russellville School District has benefited right now from Blackstone’s cooperation with Hiegel and Barrett, and the team’s desire to be environmentally friendly. Through it all, the school district has maintained its excellent standing in the state. Hiegel pointed out that of the 430 schools in the state, London Elementary School ranks fourth for taking care of its facilities.

“We fix these things,” Hiegel said. He described the pavement distresses of the parking lots prior to the repairs as “most of it was moderate,” but the school board has to work proactively. “We have to schedule it a year or two in advance for budgeting and getting the money approved,” Hiegel said. “The school is proactive on these matters.”

Not only the school, but the contractor nearby is proactive. Blackstone Construction’s planning for environmental sustainability puts them on the leading edge of recycling efforts going forward.