Concrete and asphalt are recycled throughout the United States, but the South can stake a strong claim as the preeminent region for producing aggregate.

Each of the top five companies on Construction & Demolition Recycling magazine’s updated list of the 20 largest recycled aggregates producers in the United States operates partly or exclusively in the South.

The state of Texas in particular boasts three of the top five entrants on the list. A booming economy, a supportive department of transportation and the efforts of committed entrepreneurs have all helped the Lone Star State live up to its reputation as a leader in the space.

Cost-effective and green to boot

The construction of highways, bridges, and commercial and industrial buildings calls for a considerable amount of concrete and asphalt, as well as the aggregate stone products needed to make them.

Business owners of all types understand that time is money, but contractors requiring bulk amounts of building materials also realize that distance is money.

That latter part of the equation has helped recycled aggregates producers in Texas find homes for their materials, as most active construction zones may be dozens or hundreds of miles from the nearest quarry—or the nearest landfill.

Trey Brown of Dallas-based Big City Crushed Concrete explained it well in a 2017 write-up prepared by equipment maker Komatsu, which supplies his firm with loaders and excavators.

In talking about his company’s multilocation strategy in the Dallas-Fort Worth area, Brown commented, “From a trucking standpoint, multiple locations provide a major advantage. Contractors bringing materials to us have shorter hauls compared to when we had one or two yards, and this holds true on the other end for companies picking up the products we make. Reduced transportation costs help their bottom lines, and they are getting quality products that are as good as, or better than, virgin materials from a quarry.”

Southeast of Dallas in Houston, both Cherry Crushed Concrete and Southern Crushed Concrete (SCC) have become large regional producers following a similar formula.

On its website, SCC describes itself as “a Texas-based company that uses practical and inexpensive methods to produce recycled concrete and asphalt for a variety of construction projects throughout Southeast Texas. Our recycling replaces the need for rock, which must be trucked into the Houston area from distant quarries, making the use of our recycled products efficient and cost-effective for a range of projects.”

A recycling-friendly Texas Department of Transportation (TxDOT) has been another shot in the arm to secondary aggregates producers in that region. TxDOT says it “reclaims and reuses about 1 million tons of recycled concrete pavement (RCA) annually.”

While Texas may lead the way in overall aggregates production, support for, or investments in, concrete and asphalt recycling are by no means restricted to the state, with Fortune 500-scale firms now competing with entrepreneurs to take part in the sector.

Corporate competition

Vulcan Materials Co., Birmingham, Alabama, No. 2 on our list, had revenue of nearly $4.3 billion in 2018 and describes itself as the largest aggregates producer in the United States.

The firm has some 200 operating locations in 20 different states. Many of these are quarries, but the company also has 17 locations listed as focusing exclusively or predominantly on producing recycled aggregates and 49 total that host some recycling activity, according to Vulcan Materials’ Economic Analysis Manager Baron Worthington.

The company cites the cost-effective and convenient nature of using recycled aggregates as one reason behind its recycling sector investments, noting on its website, “Recycling practices are employed where specifications and market conditions allow and the operation can support the activity.”

As a publicly traded firm attempting to appeal to institutional and individual investors, Vulcan also touts the sustainability aspects of recycling concrete and asphalt. “Our ongoing efforts to reduce emissions and recycle materials are vital to the environment, to our neighbors in local communities across the land and to our bottom line,” the company notes on its website.

Larger yet than Vulcan Materials is Switzerland-based LafargeHolcim. The multinational firm focuses on cement and ready-mix concrete production, but it too has invested in or acquired aggregates recycling assets.

LafargeHolcim cites the desire to “multiply by four our volume of recycled aggregates from construction and demolition waste and reclaimed asphalt paving” as one of its two main circular economy targets to reach by 2030.

The company also says it wants to “use 80 million metric tons per year of resources made from waste in our operations.” In addition to producing secondary aggregates, this can include using scrap tires and other discarded materials as fuel in cement kilns.

The scale of LafargeHolcim, as a company with $26 billion in annual revenue and more than 350 locations in the United States alone, means that if it has any presence at all in concrete and asphalt recycling, it is likely to be a noticeable one.

Wearing of the green

Government support, or lack thereof, for concrete and asphalt recycling can swing depending on the people or party in power and their legislative priorities.

A seemingly more permanent influence affecting the industry in the past several years has been the adoption of Leadership in Energy and Environmental Design (LEED) standards by developers and property owners.

The LEED scorecard is organized and updated by the U.S. Green Building Council (USGBC) and focuses on a variety of building practices, including site selection, energy and water use.

The LEED 4.0 checklist and scoring system, which helps determine how energy-efficient a project is, has 13 out of a total possible 110 points dedicated to materials and resources.

According to the Skokie, Illinois-based Portland Cement Association (PCA), credit No. 4 in the LEED Materials and Resources section can be earned when “a minimum of 25 percent of building materials that contain in aggregate a minimum weighted average of 20 percent post-consumer recycled content material, or a minimum weighted average of 40 percent post-industrial recycled content material” is used.

Adds the PCA, “Using recycled aggregates instead of extracted aggregates would qualify as post-consumer. Because concrete is an assembly, its recycled content should be calculated as a percentage of recycled material on a mass basis.”

With the USGBC claiming that some “2.2 million square feet is LEED certified every day, with more than 90,000 projects using LEED,” any tie-in between green building and concrete recycling is likely to produce benefits for the 20 companies on this list and those striving to join them.

The author is the senior editor with the Recycling Today Media Group and can be contacted at btaylor@gie.net.

Inconsistency is inevitable when it comes to the incoming materials recyclers are charged with handling. It is coming up with solutions for dealing with these inconsistencies that can make or break a construction and demolition (C&D) recycler’s operations.

Two years ago at Mercer Group International, this kind of material inconsistency resulted in hours lost to downtime every day.

Mercer Group International is a family-owned and -operated C&D materials recycling facility (MRF) and transfer station based in Trenton, New Jersey. It processes hundreds of tons of materials a day, recovering plastic, cardboard, wood, vinyl, PVC, concrete and metal. But the facility also processes hard-to-recycle items, like plastic bags and long plastic ribbons, that become intertwined with large wooden boards and sheet metal during separation.

It’s these difficult-to-recycle items, in addition to some other conditions, that led to difficulties in operations at Mercer. For example, when material got wet or cold, it would create sticking issues on the company’s existing screen. In addition, the way the grapple loaded the material onto the screen varied, sometimes resulting in clumps of material that were difficult to pick apart.

These issues together caused a problem that is all too common in recycling facilities: Mercer’s primary screen would jam almost every hour, each time causing the entire line to shut down as employees worked to unclog the unit.

“We would have to shut the line down and spend 15 minutes cleaning it,” Jeff Wilbur, general manager at Mercer Group International, says. “We were almost losing 15 minutes an hour when it blocked up, and we would have to shut the line down maybe six to eight times a day.”

When the jamming became routine, Wilbur decided to seek a change.

New solution

As a longtime customer of General Kinematics (GK), based in Crystal Lake, Illinois, Wilbur turned to the company’s leadership team for a solution.

“Part of the challenge was being able to process enough materials for the day without having the issues that they had for stoppage and the hang-ups that came along with that,” says Dick Reeves, the director of resource recovery for GK.

Because of the type of material Mercer was processing and the demands placed on the equipment, GK Territory Sales Manager Robert Wasilewski recommended GK’s Finger-Screen Vibratory Screener 2.0 to handle the tonnage of large, abrasive materials that found their way through the line during Mercer’s rigorous eight to 10 hours of run time each day, five to six days a week.

The Finger-Screen 2.0 is a new model from GK that features a vibratory action to spread material evenly across the entire deck, while tapered fingers designed in staggered positions are employed to help prevent material bypass. The unit separates materials based on 3D sizing to result in minimal blinding or maintenance needs.

While the Finger-Screen 2.0 features many of the workings of GK’s original Finger-Screen Vibratory Separator, one new feature is the in-tandem design arrangement that offers two alternating trough sections. One rests slightly above the other, providing an initial screening area that separates materials based on size before a constant vibration shakes the items down to the second section for further separation. Wasilewski says the initial trough works to remove any potentially destructive contaminants, while the lower trough is designed to reduce trapping and allow the rest of the downstream equipment to operate more effectively.

The two troughs run out of phase, which means they run on different vibration frequencies, to counterbalance the transmission of loads into the system. Varying frequencies not only move the materials with more efficiency, but also assure that the system doesn’t experience problems with mechanical resonance and breakdowns.

The Finger-Screen 2.0 also utilizes a higher stroke than its predecessor, translating into faster travel rates and more energy into the product to provide better separation and screening. The adjusted level of vibration results in a longer displacement, which moves traditionally difficult-to-screen materials more efficiently through Mercer’s system. The longer displacement allows the unit to push through the elasticity of materials, like plastic bags and other flexible plastics, with more ease, Wasilewski says.

“We’ve doubled the length of the stroke from our traditional vibratory screen,” Reeves says. “With that increased stroke, we get better separation, faster travel rate, it helps with the turnover of materials so we get more fines down below the deck, and also helps the customer through the use of the secondary screen.”

In addition to trying to utilize the existing supports Mercer had in place from the old screen, General Kinematics was able to integrate the Finger-Screen 2.0 with the existing structure eliminating additional cost requirements for a new support structure.

Installation process

Once Wilbur decided on the Finger-Screen 2.0, GK got to work designing and building the unit. GK customizes each machine depending on its application after working with facility owners to assure the system works for the specific types of materials they process. For this application, the GK team took the feedback from Wasilewski and his team into account to customize a workable solution for Mercer’s specific pain points.

“Every system is unique and has its own challenges, and with this one, we actually went a little bit wider and a little bit longer on the length to accommodate these larger, bulkier products that are coming through here,” Reeves says.

Once the unit was built and tested, GK representatives had it installed by late December 2017. After the installation, GK worked with Wilbur to tweak the machine for his particular operations and materials. The speed and stroke of the machine, the conditions of the materials being loaded and the way they’re loaded can all affect a system’s efficiency, so GK representatives observed the operations in real time and made adjustments as necessary.

Once tweaks were made, it was time for Mercer to see how its new screen would fare against its most challenging incoming materials.

Seeing Results

Mercer International was the first facility in the country to implement GK’s newest model of vibratory screener. While serving as the “guinea pig” for new equipment can sometimes be a daunting idea for facility managers, Wilbur says his past experience with GK gave him the confidence to put the screen through its first real-world trial run.

“Knowing that it wasn’t your typical construction and demolition site, this was a great opportunity for the Finger Screen 2.0 to be put in place and utilized,” says Wasilewski.

The leap of faith paid off for Wilbur, who says downtime and clogging have decreased since the unit was installed, while materials recovery has improved significantly.

“We did the upgrade in December 2017, and it’s really helped us tremendously. It’s helped us with throughput because it doesn’t clog up the way our old system used to, and our rear screen has actually helped us create a third more recovery in our fines,” Wilbur says. “Efficiency and throughput have definitely increased. We run an efficiency rate up around 90 percent right now.”

Now, even with inconsistencies in incoming material and standard loading challenges, Wilbur has been able to pull out more ferrous, nonferrous and other recyclable byproducts than before while ultimately reducing the amount he’s sending to the landfill.

“The GK equipment that was put in here is the best we’ve ever had. It’s obviously their latest and greatest machine that they have out,” he says. “I think the dual system works. It helps material get flipped over and eliminates that surfing event with fines and dirt. ... It just doesn’t clog up anymore.”

The author is assistant editor for C&DR and can be contacted at tcottom@gie.net.

When word got out that Old Dominion University in Norfolk, Virginia, was going to demolish the iconic 82-year-old Foreman Field to pave the way for a new football stadium, demolition companies across the region bid for the job.

North Carolina-based East Coast Demolition was awarded the project, but there was a catch.

“They wanted to have one demolition company handle one side of the stadium and another company do the other,” East Coast Demolition Project Manager Richard Webb III says. “That’s when they told us one of our largest competitors in the area was going to be doing the other side.”

Macsons Inc., headquartered in Norfolk, Virginia, was tasked with tearing down the west side of the stadium. Shortly after fans watching Old Dominion’s final game against Virginia Military Institute cleared the stadium Nov. 19, the companies staged their equipment on-site.

With each contractor boasting more than 30 years of demolition experience, the companies say it wasn’t the size of the project that was a challenge, but the university’s timeline to complete the job. Because the university wanted the new stadium ready for the 2019 football season, the contractors had about a month to tear down Foreman Field, Webb says.

Proper prior planning

Weeks before the start date, Macsons Project Manager Andrew Dunnum coordinated between the company’s other job sites to make sure crews and equipment would be ready for the stadium teardown. Dunnum, who passes by the stadium every day on his way to work, says the company’s employees—many of whom have children who attend the university and go to the football games—felt a connection to the project.

Dunnum laid out 24-hour shifts for workers and planned which pieces of equipment would be used for each phase of the project. Meanwhile, Webb studied drawings of the stadium and calculated how to finish the project within 10 days of starting.

“Every project we do is to exceed the schedule that we put out. This one was no different, but it was one of the most important,” Webb says. “We knew if we ran 50 loads per day, we could move the building in 10 days.”

In planning meetings, Dunnum says Macsons founders Steve and Bill McCloud and Webb’s father, Richard Webb II, who helped found East Coast Demolition, talked like old friends.

“We had all our jokes,” Dunnum says. “‘We’re going to do [the demolition] faster than you’ taunts went back and forth, but at the end of the day, [Webb III] and I both knew to make this successful for the general contractor and Old Dominion, we had to work together as a team.”

No “I” in Team

Dunnum says that both contractors kept in close communication as they reached different phases of the demolition.

“It was actually kind of fun to have someone else in the same club as you are, just on the other side of the fence,” Dunnum says.

While East Coast Demolition and Macsons had the same goal, their approaches to the project were different. Macsons aimed to find a balance between speed and efficiency, while East Coast’s goal was to “get the building down and out.”

To bring down the stadium’s 80-foot walls, East Coast Demolition used a Volvo 480 high-reach excavator paired with a new NPK MP-28 processor, which allowed the company to reach heights of the stadium other equipment couldn’t while “providing the most efficient demolition method.”

Webb III says the company’s DustBoss also came in handy for managing dust from the project.

“Fire hoses don’t provide the best suppression,” he says. “Dust and silica dust is such an issue now, so having that DustBoss out there was a huge help to keep the dust down. We were dropping walls so fast, we had to have enough water to handle it.”

Macsons started in the middle with a Hitachi high-reach excavator and worked its way out with smaller excavators to bring down 10-foot walls on each side. In addition, Macsons had to tear down a media booth and salvage a locker room for reuse. Dunnum says volunteers from the college and community came to help salvage material, but for him, the best part of the job was that almost everyone in his company had a hand in it.

“We pulled some of our abatement guys off a job to help the demo guys out,” Dunnum says. “We told them, ‘You’re a part of the team. Please do your part. Push hard and keep your production up.’”

With residential neighborhoods nearby, noise was a big concern in the project. In fact, Webb III says he had to submit decibel readings from other projects prior to the Old Dominion teardown to show they could work at night; however, he says crews worked so efficiently that they didn’t have to worry about disturbances.

“We were prepared to run 15 guys during the day and 15 guys at night,” Webb III says. “But within the first night, we tore down a fifth of the stadium.”

Finishing the project in just eight days, Webb III credits his crews for staying on task.

“My team did a really good job of keeping the pace of the project without me having to be there every second,” Webb III says. “Our guys are self-sufficient. They knew what had to be done and they took over. They took pride in it and they did a really good job.”

A job well done

Macsons recycled approximately 7,230 tons of brick, concrete and asphalt; 70 tons of debris; and 116 tons of metal from the project. To speed up the job, Macsons’ recycling yard in Bowers Hill, Virginia, processed half the material, while an outside company handled the rest.

With a goal to “clean up as we go,” East Coast Demolition picked and sorted through different materials—aluminum, concrete and brick—to recycle throughout the project.

“Since recycling material reduces costs for disposal, we tried to recycle as much concrete, brick and asphalt as we could,” Webb III says.

Because of the stadium’s rich history and ties to the community, local media covered the project extensively. The university even set up a live webcam of the site to track its progress.

“People don’t always know exactly what we do, so seeing our company in the paper and people posting on social media was neat—especially since we were able to finish early,” Dunnum says. “It’s something you can take pride in.”

With construction of Old Dominion University’s new stadium underway, Dunnum and several other employees have kept a piece of Foreman Field as a token of history.

“I have a brick in the back of my truck bed that I’m going to hold on to,” he says.

The author is digital editor for the Recycling Today Media Group and can be reached at kmaile@gie.net.

The rocket launch towers at Launch Complex 17 in Cape Canaveral, Florida, have withstood hundreds of high-impact blasts. Over a span of more than five decades, the towers stood firm as hundreds of rockets and other aircraft launched into space from their steel beams, leaving nothing behind but a trail of sparks.

With one last explosion in July, the two towers finally toppled to their fate in a cloud of smoke.

Demolition crews recently took out the two fixed launch towers on pads 17A and 17B at the Cape Canaveral Air Force Station to clear way for commercial operator Moon Express to launch moon-bound expeditions in the future. Located near the southern perimeter of the sprawling Air Force station, Complex 17 was one of the Florida spaceport’s oldest launch pads from which 325 missiles, satellites and rockets launched between 1957 and 2011.

Ames 1 LLC of Anchorage, Alaska, subcontracted D.H. Griffin Wrecking Company Inc. (DHGW), Greensboro, North Carolina, for the demolition work, which included the two towers, one of the launch pads, multiple ancillary support structures and all associated footings and foundations within the complex.

DHGW spent four months developing an initial plan to mechanically fell the structure.

Once contractors began pre-cutting steel structures, though, they discovered they’d need a new plan.

“As we started exposing columns and preparing for the precuts, we discovered that the degree of corrosion on and within structural members was too great to guarantee the necessary structural integrity required to safely proceed with this method,” says Karen Soricelli, a division manager at DHGW who helped oversee the project. “We made the decision to consult with Dykon Explosive Demolition Corp. (Tulsa, Oklahoma) and asked our client to appeal to the Air Force to allow for the utilization of explosive means in felling the towers.”

Plan B

Demolishing steel structures by means of explosion on a military base in the middle of Florida is no easy feat. Once explosives entered the picture, the Air Force implemented an additional set of stringent safety guidelines for carrying out the demolition—including a 99-pound cap on the amount of explosives that Dykon could use.

Successfully working within the limitations required almost an entire extra year of extensive planning coordinated between the three contractors and the Air Force. DHGW also hired two outside engineering firms to perform structural analysis and stamp the plan, along with another outside contractor to perform continuous monitoring throughout the prep work.

“Working on a military base always entails a heightened level of security. The process for approval regarding the change in method and use of explosives was lengthy due to the number of departments within the Air Force that had to review the plan,” Soricelli says.

The complex’s southern location presented an additional challenge, Soricelli adds, as the area was prone to seasonal thunder and lightning storms, and even hurricanes, that could delay work.

To develop the explosive plan, Jim Redyke, the president of Dykon, says he and his team walked the site and measured every particular, down to the individual columns, to help determine the quantity of explosives needed to fell the 190-foot towers.

While the site was relatively empty, the Air Force outlined which direction it wanted each structure to fall for cleanup purposes—Redyke just needed to figure out how to do it with limited impact.

“I think preplanning and engineering requirements are probably the most important things that are needed for a good blast. Owners always want to see exactly how you’re going to do it, so the more detail you give them going in, the more of a comfort level they can have,” Redyke says. “That’s part of good planning in any type of job: attention to detail and checking to make sure you have everything you need to know about the structure so you can plan accordingly.”

Minimizing the impact

After months of preparation and planning, the Air Force approved Redyke’s plan to use 97 pounds of explosives—just two pounds shy of the maximum allowed on-site.

Dykon was able to limit its use of explosives by torching the structure to pre-weaken it before the blast. The towers’ sturdy steel cross-brace composition, especially at the base of the structures, posed a challenge for contractors, who needed to eliminate some density at the base to create frame consistency all the way through the structure for easier control.

“The real secret is the art in the torch work you do,” says Ron Gilbert, the vice president of operations for Dykon. “Pre-weakening the structure with a cutting torch mitigates the amount of explosives you need.”

After abating asbestos and polychlorinated biphenyls (PCBs), demolishing the concrete launch pads and removing several ancillary structures on the site, contractors got to work methodically slicing through select intersections of steel beams, cutting slots into the columns that would help the towers topple in the right direction.

Once the structure was weakened, Protec Documentation Services Inc. of Hainesport, New Jersey, performed surveys of all structures on-site that were to remain to help assess any damage claims following the blast.

Prepare for blast-off

Before the detonation, the Dykon team placed 900 grains per foot of linear shaped charges in the towers to sever structural members, along with nitroglycerin-based dynamite to displace them. Explosives were placed about 43 feet high, leaving some of the tower intact near the bottom for the structure to pivot on to help direct its fall.

“If you can leave up a portion of the building as blast protection and tear it down later, that is important,” Redyke says.

The exact placement of explosives and sequencing of detonation, though, are details contractors keep close to maintain a competitive edge. “Every blaster is like a chef in the kitchen. Everyone cooks different, so you don’t want to let all your secrets out,” Gilbert says. “It’s cookie-cutter in a lot of respects, but you’ve got your own touches that you put in the food.”

Prior to the demolition, contractors designated impact areas and set up a safety perimeter. The Air Force required all spectators and personnel to remain at least 2,000 feet away from the towers, so Redyke spent nearly an hour routing a detonating cord to the designated site to use with both non-electric and electric detonators.

Protec was on-site the morning of July 18 to conduct seismic monitoring of the vibrations produced by the explosion, along with dozens of onlookers to say their final goodbyes to the historic towers.

The launch complex was built in 1956 to test the first operational ballistic missile in the U.S. arsenal. Over the years, its ownership was passed between the Air Force and NASA, making it a starting point for dozens of notable missions, including the Mars Exploration Rovers, Spirit and Opportunity.

With so much history, it was only right that a familiar face administer the towers’ final blast. After a warning siren, a countdown and a call to “fire in the hole,” Brig. Gen. Wayne Monteith, commander of the Air Force’s 45th Space Wing, pushed the detonator’s plunger.

Five loud pops sent the cereal box-shaped towers tipping in opposite directions: one fell toward the south, while its attached mobile tower and the other fixed tower fell to the north. Within 10 seconds, the towers were steel ruins on the ground.

Cleanup

Following the blast, DHGW mechanically demolished the remaining lower portion of the towers using hydraulic shears and took out the rest of the concrete foundation. Crews recovered approximately 1,400 gross tons of steel and more than 10,000 tons of concrete, Soricelli says—a majority of which was recycled, along with some asphalt and nonferrous metals.

Now that the towers were successfully demolished, a new generation of space explorers are moving in—all thanks to the careful collaboration among contractors who worked to clear the site to plot a new course of history.

“I always want to make sure the world knows these are joint efforts,” Redyke says. “Playing the team role here is really important.”

The author is assistant editor for Construction & Demolition Recycling and can be contacted at tcottom@gie.net.