Asphalt Pro - February 2022

The Recycling Issue

asphaltPRO PRODUCTION – PROFESSIONALS – PRODUCTS

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CONTENTS

asphaltPRO February 2022

DEPARTMENTS

46

EDITOR’S LETTER

6 – Resilient Planning Engages Recycled Asphalt

SAFETY SPOTLIGHT

8 – Carolina Sunrock Celebrates Sterling Safety Record

By Sarah Redohl

MIX IT UP

12 – States Balance RAP Content for Successful High Polymer Use

By Tom Kuennen

THAT’S A GOOD IDEA 18 – Add a Mirror to the Paver

By John Ball

PAVEMENT MAINTENANCE

20 – Three Keys to Quality Chip Seal Design

By AsphaltPro Staff

PROJECT MANAGEMENT

12

26

22 – Improve Infrastructure with Manhole Maintenance

By Aaron Barr

PRODUCER PROFILE

26 – SteelPhalt Gives Steel Slag a Second Life

By Sarah Redohl

WOMEN OF ASPHALT

32 – Meet a Woman of Asphalt: Superior Asphalt’s Danielle Sands

By Sandy Lender

INTERNATIONAL SNAPSHOT 52 – Puma Bitumen Adds Sustainability in Australia

By Roads & Infrastructure Staff

PRODUCT GALLERY

54 – Optimize Your Production Veil

By AsphaltPro Staff

FEATURE ARTICLES

The Recycling Issue

asphaltPRO PRODUCTION – PROFESSIONALS – PRODUCTS

36 – Another Way to Optimize RAP Efficiency on Site Consider adding contract recycle preparation to your operation to increase RAP use, increase profits

By Sandy Lender

• Puma Increases RAP, Reduces Temps • CCPR for High-Volume VDOT Roads • Recycle Steel Slag in U.K. Mixes • How to Pave with RAP

Add Contract RAP Processing FEBRUARY 2022 WWW.THEASPHALTPRO.COM

OFF THE MAT

58 – Infrastructure Law Presents Construction Opportunity

By Tarun Nimmagadda

NEW TECH

60 – Sustainable Machines

By Sarah Redohl

HHIW

66 – Bergkamp’s SPECS

40 – How to Pave RAP Mixes Produce consistently in the field for successful paving with reclaimed asphalt pavement mixes

By Bryce Wuori 44 – Smart Inspections A look at the future of stockpile inspections for the aggregates industry

By Krishnan Hariharan 46 – Central Plant Recycles it Cold

By Tom Kuennen

ON THE COVER Take the steps to set up your own RAP processing operation or to start a contract crushing operation for extra income. See related article on page 36. Photo courtesy of Astec Industries

E D I TO R ' S L E T T E R

Resilient Planning Engages Recycled Asphalt

T

he recently released “World Green Building Trends 2021” SmartMarket Report from Dodge Construction Network offers data related to strategies architects, builders, investors, and others use—or plan to use—to improve sustainability in the design and construction industry. The report dissects the attitudes and plans of construction industry members from around the world.

I’d like to zero in on the “Design for Disassembly” section. The report states: “A critical way to reduce carbon and waste in the built environment is to have building products and buildings designed so that the various components can be reused when the building reaches the end of its lifecycle.”

While the report speaks to vertical construction, I wish to apply to pavements the concept of planning during the design and construction phase for disassembly and recovery. In fact, this is a concept with which the asphalt industry is already familiar. As a member of the asphalt community, you should be able to easily share the fact that asphalt pavement is the most recycled product in America. Let’s look deeper.

Asphalt pavements can be milled (disassembled) and the components (asphalt binder and aggregate) recovered for reuse in a new pavement. There are ways to perform this recycling in place or with recycling plants located near the paving site (check out the cold central plant recycling story on page 46).

Using reclaimed asphalt pavement (RAP), recycled asphalt shingles (RAS), warm-mix asphalt (WMA), Ultra Lo-NOx burners, and other environmentally sound practices to design and produce asphalt pavement mixes adds “green” value to whatever rating system a construction project might be working within. The “World Green Building Trends 2021” report showed “a slight decline in the share of green projects that use a rating system” but still used nearly 80 pages to discuss the importance the construction industry places on the use of green practices, which, when applied to a rating system, increase the builder’s social score.

Most of us have heard of LEED Certification, which focuses quite solidly on buildings.

Many moons ago, before AsphaltPro posted its content online, we wrote about using WMA in constructing parking lots to increase a prime contractor’s LEED score. This is still a good idea, but I now posit LEED isn’t the place to focus attention.

LEED is one blip on the radar where we can use the scientific given that the asphalt industry lowers your urban heat island score if you pave with heat-absorbing—rather than heat-reflecting—surfaces around your buildings. Albedo matters, after all. But does an asphalt contractor make enough money off a parking lot job to justify the marketing hassle of convincing project owners to use WMA around their new construction? Maybe. The better place to harness goodwill for the asphalt industry appears to be with other rating systems such as ENVISION® or ENERGY STAR®.

We can do much in the march toward net zero when we focus efforts on rating programs that assist in lowering energy consumption at the HMA facility, hauling, and so on. No matter which green rating system you find easiest to navigate, they are typically designed to offer ideas for lowering your carbon footprint while third-party certifying your successes.

As NAPA’s Richard Willis shared with me recently, the Federal Highway Administration (FHWA) isn’t looking at what entities have done in the past to green up their industries. The fact that the asphalt industry lowered its emissions by 97% while increasing its production by 250% from 1970 to 2001 is laudable, yes, but, in the eyes of FHWA, it’s also forgettable.

It’s nice that the asphalt industry is extremely clean. Now what have we got planned for tomorrow and how will we employ our provable green practices to improve not just pavement lifespans, but our industry’s resiliency?

Stay Safe,

Sandy Lender 6 | FEBRUARY 2022

February 2022 • Vol. 15 No. 5

asphaltPRO 602 W. Morrison, Box 6a Fayette, MO 65248 (573) 823-6297 • www.theasphaltpro.com GROUP PUBLISHER Chris Harrison chris@ theasphaltpro.com PUBLISHER Sally Shoemaker sally@theasphaltpro.com (573) 823-6297 EDITOR Sandy Lender sandy@theasphaltpro.com (239) 272-8613 ASSOCIATE EDITOR Sarah Redohl sarah@theasphaltpro.com (573) 355-9775 MEDIA SALES Cara Owings cara@theasphaltpro.com (660) 537-0778 ART DIRECTOR Kristin Branscom BUSINESS MANAGER Susan Campbell (660) 728-5007

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S A F E T Y S P OT L I G H T

Carolina Sunrock Celebrates Sterling Safety Record

Carolina Sunrock recently added chain guards to their return rollers on the conveyor belts at its Butner quarry, pictured, to improve safety for people and vehicles traveling beneath the belts.

BY SARAH REDOHL

W

e live by a simple saying here,” said Gregg Bowler, president of Carolina Sunrock LLC, Raleigh, North Carolina. “‘Do the right thing.’ That’s what we strive for every day, and operating safely is a big part of doing the right thing.”

Carolina Sunrock, a construction materials supplier producing asphalt, aggregates, concrete and recycled materials in North Carolina and Ontario, Canada, was recently recognized by the National Stone, Sand and Gravel Association (NSSGA) as one of its Louis Griesemer Sterling Safety Award winners. The company won the silver award for achieving among the lowest injury incidence rates of NSSGA’s member companies in the medium-sized operations category.

In the past five years, Carolina Sunrock has grown substantially, doubling its total number of employees. Today, the company employs more than 450 people. Alongside the growth of the company, Carolina Sunrock has also expanded its safety program.

“Safety has always been a priority for our owner and chairman Bryan Pfohl, and we have had a great safety program over our 74year history,” Bowler said. “We’ve always been committed to safety, but since we hired [Safety Manager Jason Jude] seven years ago, he’s taken our safety practices to the next level.”

EMPLOYEES ENGAGE IN SAFETY

One of the first initiatives Jude established was employee involvement groups (EIGs), a concept he adopted from his days in the coal mining industry. These monthly meetings offer all employees an opportunity to 8 | FEBRUARY 2022

discuss safety observations and outline action items to resolve any concerns.

“We have to have buy-in from the boots-on-the-ground guys,” Jude said, adding that many new safety initiatives are employee-driven. “If they’re involved in the safety process and they see results from their suggestions, they’re more likely to buy into the program. People support what they create.”

For example, Carolina Sunrock recently added chain guards to their return rollers on the conveyor belts at its Butner quarry, where people and vehicles regularly travel beneath the belts. “If the return roller falls, now they won’t fall onto a person, piece of equipment or vehicle,” Jude said. “That’s something an employee recognized as a hazard and brought to our attention.”

These observations from employees enable Carolina Sunrock to take a proactive approach to safety. “If you’re only looking at lagging indicators, like incidents and EMRs, you’re managing based on the past,” Jude said. “If you focus on leading indicators, like near misses and observations, you’re preparing for the future.”

Carolina Sunrock has also encouraged its employees to observe each other’s safety behaviors. For example, if someone sees another crew member not maintain three points of contact as they enter or exit a piece of equipment, they are empowered to remind their teammate about safety best practices.

“If someone reminds you about safety best practices, it isn’t something to get mad about. It shows that your co-workers care about your wellbeing,” Jude said. This is part of Carolina Sunrock’s focus on behavior-based safety.

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S A F E T Y S P OT L I G H T With help from Safe Performance Solutions, Blacksburg, Virginia, the company is creating a safety partnership between management and employees that aims to focus peoples’ attention on the daily safety behavior of themselves and others. “It’s a ‘Be your brother’s keeper’ mentality,” Jude said.

“If it feels like management versus the workers, it just doesn’t work,” Bowler said. “We have to recognize that we’re all in this together.”

NEW OUTLOOK, NEW INITIATIVES

One example of an initiative that has positively impacted safety performance at Carolina Sunrock is the company’s use of dashboard camera systems from Lytx Inc., San Diego, and fleet telematics from Geotab USA Inc., Las Vegas. The company implemented Lytx in its haul trucks in 2019 and Geotab in its pickup trucks in 2020.

The Lytx cameras, which face both the driver and the road, enable Carolina Sunrock to be proactive with safe driving behavior. If an event is logged, such as the driver talking on a cell phone, speeding more than 10 miles over the speed limit or running a red light, Carolina Sunrock will be notified so they can correct those behaviors before an accident occurs. “We can turn near misses into a positive,” Bowler said.

Geotab offers the same metrics as Lytx, Jude said, only without the video footage. The company’s fleet manager monitors notifications from both programs in real time and the managers receive the reports on a weekly basis. Any events are also factored into the company’s annual bonuses for its salaried employees.

However, both systems require a lot of trust from Carolina Sunrock’s employees, Jude said. “We’ve taken care to show people that we aren’t doing this to monitor them like Big Brother,” he said. “We aren’t even looking at the cameras unless an event occurs and we’re notified of it.”

The company has dialed in both systems so they only receive notifications about events that interest them. “The programs filter out other data, so we aren’t seeing every bump in the road that might set off the camera or telematics,” Jude said.

There have also been instances where the Lytx cameras have exonerated drivers, Bowler said. In one example, the cameras confirmed that the driver was not at fault in an incident where the truck passed through a traffic light as it turned from green to yellow. A car behind the truck called to claim the truck had run a red light, but Carolina Sunrock was able to show the State Highway Patrol video footage to confirm their driver did not run a red light.

In October 2021, the company upgraded all 150 of its haul trucks to the newest Lytx camera system, which also offers real-time feedback to the driver. For example, it gives notifications to increase follow distance if they are too close to a vehicle ahead. In this way, the cameras become not only an observational tool but a training resource.

The Lytx and Geotab technologies will be utilized in its Canadian operations beginning in mid-2022.

RAISE THE BAR HIGHER

Despite its safety success, Carolina Sunrock has plans to continue to raise the bar. “We’re definitely still not where we want to be, and we’re still working towards our goals,” Jude said. Bowler added, “We have to take it one shift at a time and realize the job is never done.”

The next initiative on Carolina Sunrock’s agenda is to go electronic with all its safety processes using software from HCSS, Sugarland, Texas. “We want to automate our paperwork practices so everything is at everyone’s fingertips and can be done by the safety folks while they’re 10 | FEBRUARY 2022

Regular training is an important part of Carolina Sunrock's safety initiatives.

Carolina Sunrock began using dashboard camera systems from Lytx Inc. in its haul trucks in 2019.

in the field,” Bowler said. “We hope that gives us more time in the field so we can focus on continuous improvement,” Jude added.

Being recognized with a safety award from NSSGA has only made the company want to work harder to improve its safety performance.

“The award gives us more motivation to continue down the road we’re on to reduce incidents and accidents to have a safer, more productive workforce,” Jude said.

Of course, keeping its employees safe is the number one goal behind Carolina Sunrock’s efforts to continuously raise the bar on safety. However, the company’s safety record offers additional benefits. “When you have a safe work environment, your insurance rates are lower,” Jude said. “And your risk management meetings are shorter,” Bowler added.

Carolina Sunrock also purchased an equipment simulator by John Deere to simulate operating a loader and an excavator in December 2019. “It gives us the ability to train employees and give them time to practice on the simulator before putting them into a real time production environment,” Jude said.

A good safety record can also help during the bidding process.

“When we’re trying to bid on particular jobs, a lot of companies look at our EMRs and we can often win a bid based on being a safe company,” Jude said. “We may not be the lowest bid, but we may have a competitive bid paired with our great safety record. And that could be the deciding factor.”

At Carolina Sunrock, it pays to ‘Do the right thing.’

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MIX IT UP

HiMA use from coast-to-coast; U.S. map indicating agencies’ experience status with high polymer-modified (HP) asphalt concrete (AC) mixtures (from State of the Practice for High Polymer-Modified Asphalt Binders and Mixtures, Transportation Research Record (TRR) 2021; and Laboratory and Field Performance Evaluation of Pavement Sections With High Polymer-Modified Asphalt Overlays, VTRC 2021

States Balance RAP Content for Successful High Polymer Use

BY TOM KUENNEN

Editor’s Note: With the asphalt industry’s desire to increase reclaimed asphalt pavement (RAP) use in mix designs, many additive suppliers are offering products to improve and/or restore oxidized binder properties to assist in raising RAP percentages. This article explores the role of high polymer modification in such efforts.

H

igh polymer-modified asphalt (HP) mixes are being adopted by state departments of transportation (DOTs) across the United States, but the DOTs differ on the percentage of reclaimed asphalt pavement (RAP) that they will use with confidence in those mixes.

Polymer modifiers can improve the performance of asphalt pavements. While modification of liquid asphalt binders with polymers has been shown to improve resistance to cracking, rutting and raveling of pavements, there is a practical limit to conventional polymer concentration.

Typically, as polymer concentration exceeds 3%, the viscosity of the binder increases such that the mix becomes more difficult to produce in the plant and less workable for the paving crew. However, Kraton™ D0243, which is a styrene-butadiene-styrene (SBS)

12 | FEBRUARY 2022

product manufactured by Kraton Performance Polymers Inc., Houston, has been used in larger percent applications than conventional polymer modifiers.

This material is labeled HiMA* (for Highly Modified Asphalt), or generically HP for high polymer, and is designed to provide enhanced durability. It is provided as a terminal blend with asphalt binder that may contain up to 7.5% SBS polymer. In addition to enhanced crackand rut-resistance, HP mixes permit durable thinner lifts, counterbalancing the increased cost of the modifier.

As a result, DOTs are looking closely at the characteristics of mix designs containing HiMA, in particular the percentages of RAP, with a goal of optimizing design for durability and crack resistance, while not overly diluting the HiMA binder content with residual asphalt binder from the RAP.

COAST-TO-COAST EXPERIENCE

Referring to HiMA as HP for high-polymer, Virginia DOT has used HP extensively. Its research arm, the Virginia Transportation Research Council (VTRC), last year released a survey of HP use by other states and Canadian provinces (State of the Practice for High Polymer-Modified Asphalt Binders and Mixtures, 2021).

“In general, HP AC mixtures have been used in a wide range of applications, ranging from full-depth AC, to thin AC overlays under heavy traffic on interstates and slow-braking loads at intersections,” the authors wrote (see sidebar).

“No major field-related construction issues in relation to mixing temperatures and in-place compaction of HP AC mixtures were reported by agencies; standard construction practices and equipment were adequate,” they wrote. But HP is a different animal, they said, adding “the majority of SBS polymers used to produce HP asphalt binders have a different chemical structure than those used to produce conventional PMA asphalt binders.”

Yet with HP mixes, states are keeping their standard practices, they found. “No changes to current routine practices were identified by agencies as part of their quality control and quality assurance program with regard to placing HP AC mixtures,” they wrote. “No practices or enforcements of specific safety, health, or environmental restrictions were identified by agencies with regard to using HP asphalt binders in AC mixtures.”

The inventory of liquid asphalt used and HP mixtures produced should be tracked on a daily basis to make sure the HP asphalt binder is not stored longer than its recommended shelf life, and warm mix additives can be used to attempt to increase the workability of produced HP AC mixtures, they concluded.

VIRGINIA CHOOSES HP MIXES

The Commonwealth of Virginia owns most of the pavements in the state, so is burdened with maintaining 5,000 lane miles of interstate highway, and another 22,000 lane miles of primary-level highways, said Jhony Habbouche, Ph.D., P.E., research scientist, VTRC, VDOT. Much of these highways are asphalt-over-concrete, and the commonwealth has been at war against reflective cracking of concrete joints, more so than fatigue cracking or bottom-up cracking.

“Reflective cracking, coming from the joint, is the major driver for VTRC and VDOT to explore more innovative technologies and alternatives in order to prevent or reduce such type of cracking in AC overlays,” Habbouche said. “We aim to totally stop reflective cracking, but this will never happen. Therefore, we try to delay it as long as we can. VDOT explored and is still exploring numerous treatment strategies to mitigate reflective cracking. This includes saw and seal, in-place recycling, crack-relief mechanism (e.g., fabric pavement interlayers, chip seals), fracture slab processes, and asphalt mixes with expected higher cracking resistance. The use of high polymer-modified HP AC mixes has been one of many promising alternatives being considered in Virginia.”

Due to its cost, Virginia uses HP only in surface mixes, as they are most vulnerable to reflective cracking. “For us in Virginia, it would not be cost-effective to go HP on a full AC depth,” Habbouche said. “We have good mixes that perform well, so really HP is used more on jobs with jointed concrete pavement where we have major issues with cracks reflecting through.”

Currently, Virginia applications treat HP-modified mixes the same as its standard polymer-modified mixes. But it’s taken the further step of using HP to bolster its stone matrix asphalt (SMA) mixes. Given their premium aggregates, higher asphalt binder content, and load of polymer modifier and fibers, inexperienced contractors may find SMA mixes difficult to place. But in 2014 and 2015, Virginia’s contractors rose to the occasion.

“Virginia was one of the first states to deal with HP SMA and I want to give credit to our very talented asphalt contractors in Virginia,” Hab-

HP base course containing 35% RAP is placed at the NCAT test track

by East Alabama Paving. Photo courtesy of NCAT

bouche said. “The first time they placed an SMA with an HP, it was difficult, whether in producing, transporting or compacting the mix. Virginia contractors can now produce, transport and compact any HP SMA mix like they would in any unmodified mix.”

These HP SMA overlays—like nearly all Virginia mixes with modified asphalt binders—contain 15% RAP, and Habbouche has not seen any problems with combining RAP with HiMA. “We haven’t seen any incompatibilities at the moment, but we’re taking baby steps,” he said.

“We are allowing up to 15% RAP, because we’ve had good experience when allowing up to 15% RAP in a regular polymer modified mix, our reference point.”

QUELL REFLECTIVE CRACKING

Most of Virginia’s initial placements of HP or HiMA mixes have been in the Northern Virginia suburbs of Washington D.C., said David P. Shiells, P.E., Northern Virginia district materials engineer with VDOT. “Northern Virginia is one of the busiest districts in the Commonwealth,” Shiells said. “We have a significant amount of the statewide construction and maintenance work, so we need to keep up with technological advances. In fact, we were the first Virginia district to try high polymer asphalt back in 2014.”

Even though the first placement of HP mix was a trial with a Superpave 9.5 mm mix in a subdivision, Shiells never lost sight of the primary application: interstate highways.

“We started small because we did not know how this material was going to perform and whether it was going to be difficult to place,” he said.

“Obviously, the main focus was on interstate pavements where we have a lot of reflective cracking from transverse joints in the underlying concrete. We were hoping that the HP mix would reduce the severity of the reflective cracking.”

In 2015, the following year, VDOT placed a HiMA on nine miles north- and southbound I-95 in Prince William County. “We used the high polymer binder in a Superpave 12.5 mm surface mix, placed 2 inches thick,” Shiells said. “That’s typically what we use on our interstates in a mill-and-resurface project. We simply replaced the regular PG76-22 binder with a terminal blend high polymer binder.” This mix also contained 15% RAP. Since then, the Northern Virginia district pioneered, and has also been successfully placing, HP SMA on the interstates.

“Trying to patch reflective cracks is time-consuming and expensive,” Shiells said. “Milling down to the concrete is difficult because we can only get a deep patch across one or two lanes at a time. We have to mill out one or two lanes, place and compact the patch material in lifts, and WWW.THEASPHALTPRO.COM | 13

MIX IT UP

In Utah, a 6-inch-thick lift of HP-modified mix containing 15% RAP is placed at Wendover truck weigh station in summer 2021. Photo courtesy of the Asphalt Institute

then repeat the process on the remaining lanes. We have a very limited window for lane closures, which are typically limited to between 10 p.m. and 5 a.m., so if we can do a regular 2-inch mill and resurface, it limits the amount of disruption that we cause to the traveling public and improves cost effectiveness,” Shiells added. All this supports HP mixes instead of deep concrete repairs.

BASES AT NCAT

HP mixes have been studied for over a decade at the National Center for Asphalt Technology (NCAT) at Auburn University. At NCAT, HiMA modifier was used in its test track sections during its 2009-2012 research cycle. There, the manufacturer’s Section N7 and Oklahoma DOT’s Section N8—repaired with HiMA—performed so well that the Oklahoma DOT decided to use HiMA on I-40 west of Oklahoma City, where it’s intended to resist rutting and reflective cracking.

This project was built in 2012 and continues to provide excellent performance. According to pavement management system data available on Oklahoma DOT’s website, in 2021 this section of highway has minimal cracking or rutting and has excellent ride quality (IRI < 50 inches/mile). NCAT’s test track also has been studying use of RAP with HP mixes via its 2012 Green Group and 2015 Cracking Group experiments.

“We started with HiMA modified binder back in 2009, when we did a full depth structural section as well as a mill/inlay using virgin mixes that performed in an outstanding manner,” said Dr. Buzz Powell, P.E., NCAT associate director and research professor. Later, in the 2012 track cycle, NCAT had a centerpiece group experiment it called the Green Group, using mixes not unlike those in many state DOTs, with RAP in the base, intermediate and surface courses.

“We had 35% RAP bottom and the middle layers, and 20% RAP in the surface,” Powell said. “We used this as the control section because those are pretty common numbers for state DOTs to use 35% RAP below the surface and 20% RAP surface.”

One section, S5, had an HP base mix containing 35% RAP and neat binder intermediate lift with 50% RAP. This high-RAP focus section, part of the Green Group, was rebuilt in 2013 due to bond failure between the base and intermediate layers. In the successful rebuild, a heavier tack coat was used, but no changes were made to the original mix design for the HiMA base mix. The rebuilt section S5 supported more ESALs than any other section in the experiment.

14 | FEBRUARY 2022

NCAT’s 2015 Cracking Group experiment relied on HP base and binder courses to preclude potential bottom-up cracking that could interfere with the study of surface cracking.

“We wanted all the cracking to be surface cracking,” Powell said, “so we built bottom layers and middle layers using HiMA and containing 17% RAP as an experimental control, and then placed a variety of different types of mixes on the surface that we evaluated in the laboratory. Pavement thickness was intentionally thin in order to produce higher deflections. We used the HP binder to make sure that we didn’t have any distresses down below the surface, that all the distresses that we saw would be in the surface layer. The HP lower pavement layers performed exactly the way we hoped they would, and we were able to isolate the cracking just to the surface layer in every test section.”

For this work the HP-modified base and intermediate layers were 2 ¼ inches thick, each containing 17% RAP, and the virgin various surface layers were 1 ½ inches thick.

UTAH’S THICK LIFT

In a summer 2021 application, Utah DOT skipped using HP-modified pavement layers in favor of a deep, HP-modified 6-inch-thick pavement placed at a truck weigh station subject to rutting. This HP mix contained 15% RAP. Previously Utah DOT had lab-tested, using the Hamburg, incrementally richer dosages of HiMA binder in a typical Utah 12.5 mm Superpave mixture, up to 6.8% binder, which closed air voids. The same slabs were tested a second time with an additional 20-pound load and still passed the 10-mm requirement.

Encouraged by these laboratory results, Utah placed two HiMA sections on state routes, in which the HP binder was substituted for conventional binder with no other changes. This led to placement of the 6-inch HP lift at the weigh station, where truck queues might require costly Portland cement concrete pavements on approaches. Evotherm** modifier was added as a compaction aid.

Why such a thick lift? “The quality of the pavement is better because we have better compaction numbers,” said Howard J. Anderson, P.E., state asphalt engineer, Materials Division, Utah DOT. “We don’t need a tack coat and we can build the pavement faster with less testing.

“That’s because we are so far past the danger area of density that we feel that we can reduce coring in the future, as the normal UDOT spec is at least 93.5% compaction,” Anderson said. “We don’t want anything that has 8% or more voids. And if everything that we’re putting down is so far above that, then our risk for density is much less and our quality is much higher.”

The lift was placed 7 ½ inches deep and compacted to 6 inches, where Utah achieved 97% compaction for the full depth. “I could have put down 8 or 9 inches of this mix, and I wanted to, but the region cut us back because we normally have asphalt projects up to 6 inches in depth,” Anderson said. “We could do that because with the compaction aid it’s lubricated enough to get density we want. That’s a target density of 96% for the top 3 inches, with lower limit to 94%.”

While this HP mix contained 15% RAP, Anderson felt he could go higher, up to 25%, as long as the total binder content was high enough to provide the lubrication for thick lift compaction and the mix passed the Hamburg rut test, but for this application they wanted to be conservative as higher RAP amounts might complicate compaction.

The original mix design called for 5.6% total binder, but in Anderson’s opinion was not enough to facilitate the kind of lubrication that would

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MIX IT UP

Florida DOT fights rutting at agricultural inspection stations with HP asphalt mixes. Photo courtesy of University of Florida

meet his requirements for voids filled with asphalt. “Because we know that we’re not sensitive to being over-asphalted, we moved it up to a total of 6% binder,” Anderson said. “At that level, we had 1% voids at 50 gyrations, we just had enough to facilitate the compaction, and it turns out it wasn’t too much. Based on our lab tests, we could have used 6.5% and still not be in a rutting situation.

“The high mod permits the higher percent, and it permits it without rutting,” Anderson added. “It’s a very different feel as you get used to this material, compared to a conventional mix. And it goes against what you’re used to. It goes against the normal rules. You’re closing down air voids and you’re putting yourself in what would normally be a rutting situation; but because the glue is that good, instead of putting you into a rutting situation, it’s just giving you an even stronger pavement.”

After more than five months of tremendous truck traffic at the I-80 port of entry, the pavement has not budged or flushed, and the performance is outstanding, Anderson said.

FLORIDA: HP, BUT NO RAP

HiMA is the Sunshine State’s premium binder to address severe rutting, bottom-up fatigue (alligator) cracking, and raveling (in OGFC mixtures).

Florida DOT uses it to enhance mixes and refers to it as a high polymer (HP) binder. Since 2015, the state’s completed 39 projects with high polymer binder and placed over 522,000 tons of high polymer mix.

According to public information, HP binder replaced PG82-22 in FDOT’s July 2017 spec book. However, it imposes limitations on its use.

It must use SBS or SB polymer only, with no polyphosphoric acid. In particular, no RAP is permitted in HP mixtures, while up to 20% RAP is allowed in conventional polymer modified mixes.

Only 0.3% of FDOT’s system is deficient due to rutting; however, rutting is a significant safety concern as traffic is increasing and rutting is occurring at agricultural inspection stations, truck weigh stations and at urban interchanges, where HP mixes are an alternative to placement of more expensive PCC slabs.

FDOT determined there is roughly a 20% increase in structural capacity for high polymer binder mixtures compared to asphalt mixtures containing PG76-22 binder.

Its performance with respect to both rutting and cracking is increased, the state said. Recently the DOT learned through research that it improves the durability or raveling resistance of OGFCs. Despite the fact that Florida DOT uses HP mixes successfully, it does not allow use of RAP in HP/HiMA mixes. Considering HP mixes are more costly, the state doesn’t want to run the risk of the residual binder 16 | FEBRUARY 2022

on the RAP diluting the effectiveness of the HiMA binder, which is delivered as a terminal blend in an exact dosage.

The February 2020 technical paper, “Enhanced Characterization of RAP for Cracking Performance,” University of Florida Department of Civil and Coastal Engineering, described research into allowed amounts of RAP in conventional polymer modified and HP mixes. It stated: • Characterizing RAP binder stiffness and RAP fineness is required to increase the current maximum RAP content (20%) in polymer modified asphalt (PMA) mixtures.

• The specific maximum RAP limits based on RAP binder stiffness and RAP fineness, proposed in the study, may be used to successfully introduce up to 40 percent RAP in PMA mixtures, and • Incorporation of 20 percent RAP in HP mixtures would sacrifice the premium benefits of HP binder. * HiMA is either a trademark or registered trademark of Kraton Corporation or its subsidiaries or affiliates, in one or more, but not all countries. ** Evotherm is a trademark of Ingevity LLC, North Charleston, South Carolina.

LEARN MORE Much more information on HiMA and its performance with RAP in the field and the lab is available from research reports referenced in this article. Please visit these sites to download the reports: Laboratory and Field Performance Evaluation of Pavement Sections With High Polymer-Modified Asphalt Overlays, by Jhony Habbouche, Ph.D., P.E., Ilker Boz, Ph.D., and Brian K. Diefenderfer, Ph.D., P.E., VRTC (2019) http://vtrc.virginiadot.org/PubDetails.aspx?id=298387 State of the Practice for High Polymer-Modified Asphalt Binders and Mixtures, by Jhony Habbouche, Ilker Boz, Brian K. Diefenderfer, VRTC; Bryan C. Smith, Virginia DOT; and Sayed Hamidullah Adel, Engineering Systems and Environment, University of Virginia (2021) https://www.researchgate.net/publication/349441542_ State_of_the_Practice_for_High_Polymer-Modified_ Asphalt_Binders_and_Mixtures Periodic reports on track activity at NCAT involving HP mixes may be viewed here: https://eng.auburn.edu/research/centers/ncat/files/ technical-reports/rep16-04.pdf https://eng.auburn.edu/research/centers/ncat/files/ technical-reports/rep18-04.pdf https://eng.auburn.edu/research/centers/ncat/files/ technical-reports/rep21-03.pdf Enhanced Characterization of RAP for Cracking Performance by Dr. Reynaldo Roque, P.E., Bongsuk Park, Dr. Jian Zou and George Lopp, University of Florida Department of Civil and Coastal Engineering https://rosap.ntl.bts.gov/view/dot/50034

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Add a Mirror To the Paver

BY JOHN BALL

T

o give your paver operator a better view of the entire material movement process, attach adjustable mirrors above the hopper. The team at APC, Golden, Colorado, installed mirrors on the left and right light brackets above the hopper. This allows the paver operator to keep an eye on mix entering and moving through the hopper from either operator platform.

To avoid end-of-load segregation, you want to keep material in the hopper. The goal is to never “see” the flow gates. You never want to see a hole at the back of the hopper, but the paver operator can’t monitor what he can’t see. The mirrors give him a view of the entire hopper, including material moving with conveyors.

HERE’S A QUICK SAFETY TIP: REMEMBER YOUR FALL-ARREST PROTECTION. YOU SHOULD ALWAYS USE A SHORT TETHER ATTACHED TO EQUIPMENT WHEN CLIMBING TO ADJUST ELEMENTS OR TO CLEAN EQUIPMENT. TAKE THE TIME TO STAY SAFE IN EVERY ASPECT OF THE JOB. This is a convex mirror—like you see on school buses for safety. The team at APC has affixed it so that it rests on the light bracket.

They’ve used a u-joint, which allows them to move the mirror forward and back, as needed.

The knob atop the u-joint allows them to loosen and tighten the grip on the mirror’s handle for ease of adjustment.

John Ball is the proprietor of Top Quality Paving & Training, Manchester, New Hampshire. He provides personal, on-site paving consulting services around the United States and into Canada. For more information, contact him at (603) 493-1458 or tqpaving@yahoo.com.

18 | FEBRUARY 2022

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Three Keys to Quality Chip Seal Design

BY ASPHALTPRO STAFF

I

f performed correctly, chip seals can be used to stop raveling, seal minor cracks and improve skid resistance, all while extending a pavement’s lifetime.

When it comes to the design of chip seals, Scott Shuler of Shuler Consultants LLC, Fort Collins, Colorado, said during a recent Transportation Research Board webinar that there are three primary factors to consider.

Chip quantity, emulsion quantity, and substrate conditions, he said, are all key to a quality chip seal. Let’s take a closer look at each of those design factors.

1. THE CHIP

“Determining how many chips to apply to the surface depends on the shape, surface texture and size of the chip itself,” Shuler said. “What you’re trying to do is apply the chips one stone thick.”

If the layer is more than one stone thick, Schuler said, not only will the excess chips not stick into the emulsion but they may also pull out chips that were embedded in the emulsion. He added that there should also be some voids so the chips have room to move when the seal is rolled. “If you can’t see some emulsion, you have too many chips on there.”

To determine the spread rate of applying chips one stone thick, Shuler recommends performing a board test in the lab.

Set down a 1-square-yard board of known weight, cover it with the chips you will be using on the project one stone thick across the entire board, and weigh the board. Subtract the known weight of the unladen board from the chip-covered board. “That will be the approximate weight to drop on the emulsion per square yard when you’re out on the road,” Shuler said.

2. THE EMULSION

The spray rate for emulsion, Shuler said, depends on the geometry of the chips.

Each chip should be embedded 30 to 50 percent prior to rolling so that the rollers and traffic will embed the chips 75 to 90 percent eventually.

20 | FEBRUARY 2022

“To do that, we must figure out what the volume of the voids is between those chips when they’re embedded and calculate that quantity of material,” Shuler said. “The calculation (for an estimated initial shot rate) is based on percent embedment times the average mat depth, or the size of the chip you’re applying.”

Percent embedment is calculated with the following formula (where W stands for loose unit weight of aggregate; 62.4 pounds per cubic foot is constant for the unit weight of water; G stands for bulk specific gravity of aggregate; T stands for traffic correction; and V stands for surface condition correction): {1 - (W / 62.4 G)} x T + V “The traffic factor is based on how much traffic you have on that roadway,” Shuler said. “Surface condition correction is based on how soft the substrate is.”

3. SUBSTRATE CONDITION

To understand the substrate condition, it’s important to measure its rigidity and texture.

Texture is measured with a sand patch test, where a known volume of sand is spread on the surface in a perfect circle and the diameter is measured to define the surface texture.

Rigidity is measured by ball penetration test, where a Marshall hammer is placed on the ball, then the Marshall hammer is raised to its maximum height and dropped on the ball. The depth the ball penetrates the pavement surface indicates the ability of the pavement to resist penetration of chips by traffic.

“If you’re applying a chip seal over a flush surface and it’s too soft, the chips are going to sink into that,” Shuler said. “You’re going to have to correct for that, or you’re going to see some flushing.” He added that extra smooth surfaces will require lower shot rates, while extra rough surfaces will call for an increased shot rate.

With the right amount of chips, appropriate emulsion shot rate, and a solid understanding of substrate conditions when designing chip seals, you’ll be three steps closer to a quality end product.

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P R OJ E C T M A N AG E M E N T

Improve Infrastructure with Manhole Maintenance

BY AARON BARR

M

anholes are as safe and secure as the surrounding roadway. Unfortunately, the American Society of Civil Engineers reported in its 2021 report card that 43% of the public roadways in the United States are in poor or mediocre condition. In any given city or suburb, there are manholes approximately every 300 feet of roadway. That means there are many opportunities for potential gotchas every time one drives along a poorly maintained road.

As John Hickey, executive director of the Asphalt Pavement Association of Oregon puts it, “Go out on any road and the chances are high that you will see a manhole that does not match the surrounding pavement.

When a manhole isn’t at the right elevation—if it’s too low, too high, or angled incorrectly—it’s difficult to compact the surrounding asphalt correctly. That asphalt is going to fail way earlier than all the other asphalt on the road, which will create a longterm repair nightmare.”

The costly impacts associated with poorly installed or maintained manholes vary, and not all are as evident as the feeling of hitting a bump in the road. Most obvious are the direct costs of having to repair road damage, including the labor costs associated with breaking up pavement, releveling the manhole and having to re-pave around it— due to the entirely preventable issues Hickey mentions above. But there are also many hidden costs of bad manholes that should be considered, and construction crews need to be given the proper tools to do it right— and safely—the first time.

ASPHALT INTEGRITY

According to the National Asphalt Pavement Association, 93% of America’s paved roads are surfaced with asphalt. When newly laid and perfectly leveled, asphalt should last anywhere from 15-20 years before preservation treatment. When cracks and premature road wear develop around a utility but not in the main sections of a roadway, however, that’s typically an issue with the utility cover’s elevation (e.g. too low, too 22 | FEBRUARY 2022

This grade adjustment with the RimRiser shows one installer can make adjustments in less than one minute.

high, tilted incorrectly) and maintenance is going to be required more frequently. Bad manhole installations lead to cracks developing around utility covers, causing leakage into the manhole, as well as creating dips, mounds or bumps that lead to further asphalt damage over time, ultimately resulting in the need to repave roads.

A straight section of road with no curbs is an easy paving job. But throw in some

variables, and things get tricky. When complex intersections are involved—including multiple underground utilities, automatic grade controls, intersections with ADA compliance, draining requirements, curbs, milled or overlayed surfaces or any other variables—paving around utilities becomes more complex, and the more important it is to get it right the first time. In short, the more precisely a manhole cover matches

the designed pavement elevation, the longer the pavement will last. If we want our roads built for longevity, manhole leveling should be part of a standardized process of laying asphalt so it’s precisely to grade every time for optimal integrity.

WORKER SAFETY

Skillfully laying asphalt around manholes might be relatively straightforward work for the highly experienced construction crew, but with today’s employment challenges, many people working on roads are not as experienced; and lack of standardized methods and processes in construction can easily lead to injury.

Hickey noted the uptick in unskilled workers. “There are experienced crew members who can pave really well, but those people are becoming fewer and farther between. Left with inexperienced crews, there is an increased risk of quality issues and injuries.”

This should be a red flag for construction management, warranting a new look at current training procedures, determining where hazards may occur, and creating simpler, safer systems and standards that are precise and easier for crews to manage.

When it comes to manhole maintenance, construction crews are largely using the age-old method of manually raising them to grade using pry bars and shims. In addition to being less precise, this manual shimming process can easily result in back and hand injuries, among others. And because manhole leveling can be last in the paving process, it’s often in the back of a foreman’s mind in terms of priority. Rushing to get the job done, particularly when relying on less experienced crews and outmoded manual methods, creates even more of a safety hazard for workers.

As Hickey stated, “Achieving a high degree of accuracy setting manholes and matching the surrounding grades using traditional methods can be difficult, and often involves multiple people, more time and more safety risk.”

Relying on “we’ve always done it that way” will continue to result in both poorer pavement quality and worker injuries.

But there are newer alternatives that don’t require multiple people, back-breaking lifting or imprecise hand placements to raise manholes to grade. Bolt- or screw-adjusted leveling systems, like RimRiser, offer precise and safer methods for workers of any

With traditional manhole adjustment, methods can be imprecise and labor-intensive with potential for injury.

skill level. With these systems now readily available, engineers can design in safety by creating specifications for manhole leveling that both support crew safety and result in higher quality paving.

EQUIPMENT AND VEHICLE DAMAGE

Uneven manhole covers can become costly problems for contractors and the municipalities that hire them. Asphalt professionals are well aware of the equipment and time costs associated with hitting a manhole cover with the paver, sweeper or milling machine, for example. What about the toll this takes on vehicles, when off-kilter manhole rings damage tires, crack rims and damage suspension systems? What about motorcyclists who sometimes weave in and out of traffic? For them, catching an edge of a manhole can be deadly, or at a minimum lead to driver accidents and injuries. The bottom line is, it’s important to set manholes correctly the first time to reduce surprise costs, delays or injuries.

ENVIRONMENTAL IMPACTS

Extreme weather events affect the integrity of roads in numerous ways, such as softening, expansion, rutting, cracking and crumbling. In 2017, 47% of manholes were flooded due to intense rainfall, sometimes leading to sewage spills as well as infrastruc-

ture damage. Cities must plan effectively to ensure manholes have modernized infrastructure, with safe and effective drainage systems and proper maintenance plans to prepare for weather events to come. And as we plan to use fewer resources in smarter ways to protect our environment, we must consider the impacts of frequent repairs due to poor initial installations and put systems in place to do it right the first time.

The fact that most manholes are almost 100 years old, and that many are raised to road level using shims made of bricks, concrete, or other odds and ends in a contractor’s bucket of shims, should be alarming. It certainly makes a strong case to upgrade and modernize current manholes and the systems used to install, level them to grade and maintain them over time.

The many costs of bad manholes are borne by road builders, contractors, municipalities, insurance companies, drivers and taxpayers.

There is no reason for this when there are simple solutions available to help ensure that manholes are set right the first time.

Aaron Barr is the founder and CEO of RimRiser. After more than 30 years working in the field, Barr developed the RimRiser bolt-adjusted technology that is now being used in projects nationwide. For more information, contact Barr at (360) 833-2277 or info@rimriser.com.

WWW.THEASPHALTPRO.COM | 23

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PRODUCER PROFILE

SteelPhalt Gives Steel Slag a Second Life

SteelPhalt’s new Cardiff plant, a Parker StarMix 4000, can produce up to 300,000 tonnes (330,693 tons) per year. In its inaugural year, the plant produced more than 150,000 tonnes (165,347 tons).

BY SARAH REDOHL

F

or more than three centuries, the city of Sheffield in the United Kingdom has had an international reputation for steel making. According to the UK’s Government News Network, the Sheffield region currently produces more steel by value than at any point in the city’s history.

Although steel remains a primary industry in Sheffield, it’s also provided an opportunity for steel-related businesses to thrive.

SteelPhalt, a Harsco Environmental company, has built a successful business making use of steel slag, a byproduct of steel making.

Since 1963, SteelPhalt has been using steel slag aggregate to produce asphalt at its plant 7 miles northeast of Sheffield in Rotherham.

Steel slag is a byproduct of steel making when molten steel is separated from impurities. Originally a molten liquid, the slag consists of a complex solution of silicates and oxides that solidifies upon cooling, according to the Federal Highway Administration (FHWA).

26 | FEBRUARY 2022

The FHWA estimates that between 7 and 7.5 million metric tons of steel slag is used within the U.S. each year, primarily as a granular base or an aggregate material in construction applications.

“From the beginning, our main purpose was to use the slag aggregate from the surrounding steel mills for asphalt projects in a 150-kilometer (93 miles) radius from our Rotherham plant,” said Julian Smith, SteelPhalt’s global strategic growth director. “That’s what we’ve been doing ever since.”

For more than five decades, SteelPhalt grew gradually, consistently and organically. Then, starting three years ago, the company began to grow exponentially as a result of increasing demand for more environmentally conscious products.

“Being net carbon zero is high on the UK government’s agenda,” Smith said. “Our products align with that goal because we are able to create a conventional product at a lower carbon footprint.” SteelPhalt estimates that its carbon footprint is 40 percent less by using steel slag in place of natural aggregate in the asphalt the company produces.

In the UK, agencies score contractors’ bids based on both cost and quality (which includes environmental impact). Although cost continues to be a major factor, Smith said agencies have increased focus on each bid’s environmental impact. “Our products provide an easy win for local authorities, since they are able to specify a greener product with no loss in quality and minimal impact on cost.”

This has been a significant driver in the company’s growth. To keep up with increasing demand, SteelPhalt has invested in two new asphalt plants since summer 2020.

NEW PLANTS, NEW MARKET, MORE CAPACITY

SteelPhalt’s existing Rotherham plant is the busiest independent asphalt plant in the UK. With the opening of a second plant on the same site in July 2021—a Roadstar 1500 from Parker Plant Limited, Leicester, UK, capable of producing 500,000 tonnes (551,155 tons) per year—Smith estimates SteelPhalt will be able to produce 700,000 tonnes (771,618 tons) in Rotherham in 2022.

SteelPhalt’s other new plant, opened in June 2020, expanded the company into a new market in Cardiff, South Wales. The Cardiff plant, a Parker StarMix 4000, can produce up to 300,000 tonnes (330,693 tons) per year. In its inaugural year, the plant produced more than 150,000 tonnes (165,347 tons).

It’s the first permanent asphalt plant in Cardiff in over 70 years. Smith attributes this to the availability of aggregates from the region’s many quarries (limestone, granite and basalt) and the fact that the market has long been dominated by a couple large asphalt companies. Quite simply, there wasn’t a demand for steel slag as aggregate—until now.

In the past, Smith said, steel slag from Cardiff ’s mills was primarily used in lower value applications, such as sub-base and general construction fill. When SteelPhalt was able to partner with Cardiff-based Celsa Steel, Smith said, “we were able to offer a solution that maximizes the value of this undervalued resource.”

Instead of getting rid of the slag, Celsa Steel can now demonstrate it is recycling the slag into asphalt mix designs. “This partnership solves a problem for them in the form of an opportunity for us,” Smith said.

As part of that partnership, SteelPhalt was able to locate its plant on Celsa’s land, “virtually in the city center,” Smith said. Historically, high land prices in Cardiff have made it more economical to haul asphalt into the city from asphalt plants located at the surrounding quarries. Now, SteelPhalt offers a more centrally-located option.

Being located in the city center, SteePhalt’s new Cardiff plant faced many strict environmental regulations, including strict control of emissions, noise, water discharge and also dust from stockpiles.

For example, the filter system is 25 percent bigger than what would usually be found on a plant this size to make sure the plant is as effective as possible at removing particulate, Smith said. They also planted trees and installed bunding around the perimeter of the plant to create a natural barrier for noise from other residents of the area.

“We also have controls over our vehicle movements and hours of operation in Cardiff,” Smith said. They have a set number of vehicles that can come in and out per day and can only operate Monday

Smith said that in most of Europe, any mix that can be made with natural aggregate can be made with steel slag. This photo shows 14mm steel slag from a steel manufacturer in Port Talbot, Wales.

SteelPhalt’s mix was recently used on a resurfacing project near Cardiff Castle.

through Friday from 9 a.m. to 5 p.m. However, Smith said, they’re working with local authorities to expand their hours of operations.

“We believe this constraint actually creates more pollution as a result of congestion. If we were able to extend our working window to nights and weekends, we could reduce the impact we have on commuters and day-to-day road users.”

Although Rotherham doesn’t face vehicle movement limitations, they limit running both plants at night to minimize impact on local communities. And SteelPhalt strives to make all of its plants more environmentally friendly.

WWW.THEASPHALTPRO.COM | 27

PRODUCER PROFILE “Our very first ton at Cardiff was produced at a reduced temperature 20 degrees Celsius (68 degrees Fahrenheit) below traditional asphalt,” Smith said, “and every single ton produced since has been produced at that lower temperature.”

They’ve also begun to use recycled plastics to replace a small percentage of the binder at both locations. “By utilizing the properties of the selected plastics, that’s another way we can conserve natural resources in a way that is of higher value than, say, biomass usage.”

All three plants also use recycled asphalt products (RAP) in base and binder courses. “There aren’t specific limits to RAP usage as long as you can demonstrate performance, but generally we are limited to 20 percent at Cardiff and 30 percent at Rotherham,” Smith said.

“Generally, base and binder layers tend not to use steel slag because we see it as using a high value product for a lower value application,” Smith said. In Rotherham, SteelPhalt predominantly uses quarried aggregate and RAP for base and binder courses. “In Cardiff, we may use slag in base and binder courses because we have a surplus of steel slag in that market.”

Historically, high land prices in Cardiff have made it more economical to haul asphalt into the city from asphalt plants located at the surrounding quarries. Now, SteelPhalt offers a more centrally-located option from its plant at Celsa Steel, close to the city center.

MAKE THE MOST OF STEEL SLAG

Smith said steel slag is classified as a manufactured aggregate in the UK, rather than a recycled aggregate, which means there’s no limit on its use.

“In Europe, any mix that can be made with natural aggregate can be made with steel slag,” he said. Most of SteelPhalt’s mixes exclusively use steel slag aggregate.

Smith regularly travels to educate industry professionals around the world on the use of steel slag in asphalt. This fall, he visited the U.S. to speak to departments of transportation in Iowa and Illinois where he highlighted how SteelPhalt uses steel slag.

SteelPhalt’s Cardiff plant the first permanent asphalt plant in Cardiff in over 70 years.

All three of SteelPhalt’s plants run on liquified petroleum gas (LPG) and are capable of producing warm mix. The temperature range to produce asphalt in the UK ranges from 160 to 190 degrees Celsius (320 to 374 degrees Fahrenheit). However, Smith said, it’s becoming more common to target the lower end of the conventional asphalt temperature range with the use of warm mix additives. SteelPhalt uses LowTherm 4G from SIMA Asphalt to produce at a lower temperature while achieving the same workability characteristics.

28 | FEBRUARY 2022

The steel slag at its Cardiff plant is all produced on-site by Celsa Steel; the steel slag used at the Rotherham plants arrives from several steel mills located within 2 kilometers (1.2 miles).

“Being involved in processing our materials from start to finish sets us apart from traditional asphalt producers,” Smith said. Each batch of slag is analyzed for its chemistry, and every 15 tonnes (16.5 tons) of steel slag has a documented chemical footprint. “It’s basically a quality controlled aggregate.”

As such, SteelPhalt gives its specifications to steel mills with the specific chemical parameters it’s looking for in its slag. “If slag falls out of those parameters, they will divert that away from utilization within our processes,” Smith said. The rejected slag is still reused, only in lower value processes.

“We also have robust quality control processes to treat the slag before it comes to our plant,” Smith said, which dictate how the material is to be cooled, screened and crushed. “The beauty of slag is that, because it’s a manufactured aggregate, it’s very consistent and produces a very durable aggregate once it’s treated correctly.”

In Smith’s previous jobs in the asphalt industry, he’s seen companies accept all kinds of steel slag and use it like any other aggregate, which he cautions against. “Steel slag behaves differently from natural aggregate,” he said, “and if you can harness those differences, you’ll end up with a superior product.”

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PRODUCER PROFILE Smith said that because steel slag is so dense and has a high polished stone value (PSV), it wears more heavily on certain parts of the plant. He estimates the mixer paddles and arms, as well as the screens, wear out 10 percent faster than with conventional aggregate. “Anywhere the aggregate is falling with velocity, weight and speed, you’ll see increased wear,” he said, adding that they reinforced several of these locations at the plant.

They also have to make modifications to their software to deal with slight differences with the aggregate density. “Other than that, there are no major differences,” Smith said. “Most of the differences relate to the science behind the aggregate itself versus at the plant.”

“STEEL SLAG BEHAVES DIFFERENTLY FROM NATURAL AGGREGATE.”—JULIAN SMITH

OVERCOME OBSTACLES Being located in the city center, SteePhalt’s new Cardiff plant faced many strict environmental regulations, including strict control of emissions, noise, water discharge and also dust from stockpiles.

SteelPhalt claims that the shape of steel slag can improve asphalt’s resistance to rutting while maintaining a high level of skid resistance throughout the life of the pavement. “Because of the chemical makeup of steel slag, it has a high affinity to bitumen,” Smith said, adding that the alkali characteristic of the steel slag, along with an acidic bitumen, results in high adhesion. “So, it’s less prone to issues like striping.”

Smith said steel slag also tends to absorb less water, thus has a more consistent moisture content. This property reduces the energy consumption needed to dry the aggregate while resulting in a more consistent moisture content for the mix.

SteelPhalt’s technical team also produces several products using the unique properties of steel slag. One of these products, called Steel Flow, was developed when a local authority wanted a longer lasting alternative to chip seal. Steel Flow can be applied at 15 mm (0.6 inches) thick with a traditional paver while offering high skid resistance. Another custom SteelPhalt product is Ultragrip, applied at a thickness of around 25 mm (1 inch), which uses a specific type of bitumen to provide a flexible overlay on concrete.

Another difference between steel slag and natural aggregate is that steel slag is more dense. “When you’re dealing with slag aggregate, it’s naturally heavier so you need more of it to do the same area,” Smith said. “We use less bitumen per ton in a steel slag mix than in an equivalent natural aggregate mix of normal density, but that ton with steel slag doesn’t go as far, so overall we use the same amount of bitumen per square yard.”

30 | FEBRUARY 2022

SteelPhalt faced a number of challenges getting its two new plants up and running. Opening the Cardiff plant in June 2020 was particularly difficult because it was an entirely new market for the company.

“In Rotherham, we already had a customer base and they were eagerly asking for more,” Smith said, “but in Cardiff, we were trying to bring in new customers during a pandemic when we couldn’t meet anyone face to face.” He thinks the early success of the Cardiff plant despite that challenge is a testament to SteelPhalt’s products and the plant’s convenient location in the city.

Availability of parts was a challenge for both plants as a result of pandemic-related logistical issues. Smith said patience was the key to overcoming logistical challenges. “Instead of waiting on certain parts, we looked at what we could do without those parts,” he said. For example, while they waited on a part for the RAP addition system for the Cardiff plant, they opted to retrofit the part at a later date rather than hold up the opening of the plant.

Staffing its new plants also proved challenging. Not only did they face the same workforce challenges our industry has long been experiencing in North America, but they were also facing a generous furlough scheme that Smith thinks might have kept more potential workers out of the labor force.

SteelPhalt employs 40 people across its two locations.

One solution is to attract employees from demographics who haven’t historically participated in the asphalt industry, including women.

SteelPhalt is also engaging with local schools to promote job opportunities within the asphalt industry.

“The UK is facing the same issue our industry is facing around the world in attracting a younger generation,” Smith said. He said our industry tends to be branded as an old industry, so he strives in his presentations at local schools to illustrate its relevance. “I explain to them how their old cars and washing machines go to, say, Celsa Steel, where they are recycled into steel and that we use that slag to produce asphalt.

So, they might be driving on their parents’ old cars. There’s a lot more interest when I start talking about how we are conserving the planet.”

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Meet a Woman of Asphalt: Superior Asphalt’s Danielle Sands

Danielle Sands is the CFO at Superior Asphalt Inc., Grand Rapids, Michigan.

BY SANDY LENDER

A

lthough Danielle Sands grew up sharing the construction business with her father, she joined the asphalt industry when she began her career with Superior Asphalt Inc., Grand Rapids, Michigan, in 1999.

Since then, the company has grown and her expertise in aggregates and asphalt has grown alongside the company owner, Jeff Kresnak.

Sands is now the chief financial officer for Superior Asphalt and she took some time to share with readers her experiences as a Woman of Asphalt.

AsphaltPro: What was the catalyst for joining the industry?

Danielle Sands: My father owned his own excavation company. I grew up riding in a dump truck in the summer and plow truck in the winter. I would pack a laundry basket with all the things I needed in the morning and would return when he came home.

Sometimes for lunch, sometimes not until 32 | FEBRUARY 2022

dinner. When I was looking for employment in 1999, Jeff was using a placement agency to find an accountant and business manager. The rest is history.

Jeff and I have been on an adventure together. He has been a real influence on me throughout the years. He saw the potential I had. He understood my strengths and abilities and knew exactly how I could complement the company; He gave me the opportunity to grow within the company.

When I joined the company, we were a lay down only company and I was the entire administrative staff. We were a $4MM company with approximately 25 employees.

AsphaltPro: What part of your education relates best to the career track you’re on and to the post of CFO? Danielle Sands: I received my Associates in Business Management and my Bachelor’s of Applied Science in Accounting in 1994 from Lake Superior State University.

AsphaltPro: What are some of the day-today responsibilities that you most enjoy as the CFO for Superior Asphalt?

Danielle Sands: Superior Asphalt is the $50MM company that still operates as a small business. We are able to make quick management decisions and steer the ship without the lag of many levels of management.

I enjoy interacting with the crews every day as well as the mundane business tasks. This helps us keep a pulse on the needs of our most valuable resource—people.

AsphaltPro: Why did you choose to become an executive in finance? What about that position is most rewarding to you?

Danielle Sands: I love business and the day-to-day operations and inner workings of the company. It has been most rewarding to work alongside Jeff Kresnak, owner and president, and Rick Browley, CEO, as Superior Asphalt has grown to a $50MM company that employs 145 people. The people are the

success of the company. I enjoy being able to see and interact with all positions of the company. We are like one big family.

Danielle Sands: Men respond to strength. You have to be tenacious enough to hold your own but also show respect and fairness to everyone. We train people how to treat us.

AsphaltPro: What would you say was the most challenging “obstacle” you, as a female in the asphalt industry, had to overcome in the past 20 years, and how DID you overcome that obstacle? How do you think other women in the industry can incorporate that skill or habit into their work life?

Danielle Sands: I think the most challenging obstacle was being taken seriously as a female in a male-dominated industry. Consistency, fairness and being humble to always be willing to learn from others have allowed me to grow at Superior Asphalt. You have to be willing to admit what you don’t know and seek the answers.

AsphaltPro: What is something you would tell a young lady to encourage her in this industry?

Danielle Sands: You can do and be whatever your heart desires. Work hard, be dedicated and persevere.

AsphaltPro: Will you tell us about a person who served as a mentor for you and share a piece of advice from her?

Danielle Sands: My mom. She worked two full time jobs when I was growing up and she taught me work ethic. She is the strongest person I know. She told me: “No one is going to take care of you but YOU.” Personal responsibility is as important as work ethic. If you make a mistake, own it, learn from it and don’t repeat it. Mistakes are an opportunity for learning. Work hard and you can do anything you set your mind to.

AsphaltPro: You have the respect of the men and women with whom you work at Superior Asphalt. Could you share with other women of the industry how that level of trust and respect is earned or nurtured?

AsphaltPro: Could you share with a young woman just starting in our industry what top two or three characteristics you view as vital to commanding respect in this industry?

Danielle Sands: Consistency and fairness.

Not everyone is going to like you at all times.

I call it a win if they can say you are fair.

AsphaltPro: What is the most challenging aspect for you of being in the asphalt business? (And how do you power through that?)

Danielle Sands: No two days are ever the same; I power through it all by staying calm and very organized.

AsphaltPro: What is the most rewarding aspect for you of being in the asphalt business?

Danielle Sands: The employees. They are our most valuable resource. Some of our employees have been here for 20+ years.

We raised our kids together. It’s a wonderful feeling to be a part of something like this.

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ABOVE & RIGHT: Slabs of asphalt at your site can wait for a contract crusher to arrive and process them or can be processed right away if you have your own horizontal impactor crushing plant and screen ready to do the job. The crushed and screened material on the facing page is 0.75-inch minus. Photos courtesy of Rubble Master

ANOTHER WAY TO OPTIMIZE RAP EFFICIENCY ON SITE Consider adding contract recycle preparation to your operation to increase RAP use, increase profits

A

BY SANDY LENDER

Asphalt producers and contractors don’t need a primer on how dumping rates or tipping fees are rising or how piles of reclaimed asphalt pavement (RAP) are building in some counties versus others.

With the cost of recycled material often priced at half the cost of virgin material, professionals are interested in finding the best way to get their hands on this product. With the growing interest in increasing

36 | FEBRUARY 2022

RAP use to further the industry’s good standing in the march toward net-zero, professionals are also interested in finding the best way to use this material.

Stockpiling RAP requires planning ahead and proper management, as discussed in our February 2016 edition and others, but building the on-spec stockpile starts with crushing and screening if you’re doing it right.

ROI TIME

If you intend to fractionate your RAP to perfect it for mix designs, you have options. You could rent a crusher and scalping screen on a weekly or monthly basis to separate the existing “mountains” at your site into prepared stockpiles of on-spec material. You could have a company come in with portable equipment and crush your material into piles for you on a per-job basis or predetermined schedule. Depending on the amount of material you’re moving through your operation, you could invest in the equipment to do your own crushing of recycle material at your leisure. This third option opens the door to another revenue stream, which we’ll touch on below.

When is the right time to hire a contract crusher versus investing in your own equipment? The team at Eagle Crusher shared that there’s no cut-and-dry answer to that one. Each company will need to do the math to determine when equipment purchases will offer a quick enough return-on-investment to pull the trigger. Without flinging more clichés at you, let’s look at some basics.

René Wagner of Rubble Master Americas Corp., St. Ennis, Texas, reminded readers that your time is worth money. He suggested asking yourself how easily you can get a contract crusher to process your materials in a timely manner. Look at how often you’ve been placed on a waiting list behind other customers waiting for crushed product. “Can your crushing contractor process all your desired materials and specs?” Wagner asked. “What does it mean for your business to have a contract crusher in your yard processing your materials? In many cases, this imposes a major interruption of your day-to-day operation.”

If you elect to rent a crusher from a dealer to process material yourself, you must have enough work/enough material to keep the machine working for the whole week of the rental. A crusher sitting idle in the yard is a crusher that’s costing you money.

If you’re renting a crusher multiple times a year or hiring a contract crusher to set up on your site frequently, it’s time to run the numbers on starting the operation on your own. Chris Worley is the product sales specialist for mobile crushing/screening at Astec Industries, Chattanooga, and he also shared some wisdom with readers. “I would say, if a customer is paying a contractor or renting the equipment to crush and screen their RAP 40% of the time or more in a given year,

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then they should look at doing it themselves. If the contractor owns the equipment, they can better control when and where the equipment needs to be if they have multiple locations, versus having a contractor come in and crush.

“Also, owning the equipment—versus having a contractor come in and process the RAP—will give the contractor better control of the products being made if specs change for the RAP or if they need to increase the percentage of RAP in their mixes. Lastly, if the contractor chooses to rent the equipment versus owning it, then their cost per ton will be much higher. Owning the equipment will give them a better advantage when they are bidding new work due to the lower cost per ton to process the material.”

“I WOULD SAY, IF A CUSTOMER IS PAYING A CONTRACTOR OR RENTING THE EQUIPMENT TO CRUSH AND SCREEN THEIR RAP 40% OF THE TIME OR MORE IN A GIVEN YEAR, THEN THEY SHOULD LOOK AT DOING IT THEMSELVES.”—CHRIS WORLEY

The RM 90GO! compact crusher is a closed-circuit impact crusher. This model has been in production since 2000 and is popular among paving, site-work and crushing contractors for high performance and mobility.

Its top capacity is rated at 200 TPH. Photo courtesy of Rubble Master

START SMARTLY

While there are multiple stages of crushing and multiple pieces of equipment you could add to the recycling crushing process, you can start out with just the crusher and the machine that feeds it, according to the experts at Rubble Master.

“Impact crushers are the tool of choice for processing asphalt,” Wagner reminded us. “Many contractors start out with a mobile closed-circuit impact crushing plant to turn their peeled or milled asphalt into a base or subbase product. The smaller the infeed or the finished products get, the more screening capacity you need. A mobile scalping or incline screen in combination with your mobile impactor provides the screening capacity you need to achieve high outputs and low wear with small materials.”

You could start with the impactor (and excavator or loader) and add support equipment a year or even two years later.

1. start with the impact crusher 2. add the scalping screen in front of the impactor 3. add a stacker later, maybe when you make the decision to start contract crushing “The customer would want to look at getting a horizontal impactor crushing plant, a screen plant and conveyors, all of which could be track, portable or stationary, depending on how many sites they have and how often they would need to move the equipment,” Worley said. “If the customer is fractionating their RAP, we would recommend using the multi-frequency screen.”

You don’t need a 10-person crew for this new operation, but you do want the personnel to be mechanically inclined and well trained.

These workers need to be listening to the machine(s) and be able to identify if something is starting to go wrong.

CONTRACT-CRUSH RECYCLE

When you make the decision to crush other producers’ material for them, portability is paramount. Next up is preparation. You’ll want your customers to be fully aware of your requirements for material going through your crusher. The material they have on their site could be full of rebar, crossbeams or other surprises if you’re will38 | FEBRUARY 2022

When the time comes, adding stackers will open more opportunity for the contract crusher. Photo courtesy of Rotochopper

ing to crush more than RAP. If you’re willing to have your operator pick through “blended” demolition material prior to crushing, then you can set your prices accordingly, but that’s a concern to work out ahead of time. The last thing you want is to send your operator and ground man to a site where the material is full of detritus when you thought it was ready for crushing. Demo material full of detritus is not ready to go through your crusher.

You want the foreman to set up the site in the most efficient manner to feed the crusher from the excavator in a manner that keeps dust down, keeps the crusher flowing properly and keeps extra fines—or surprises—from damaging your equipment. Wagner suggested, “Have only your own factory-trained operator run your crusher. An inexperienced operator can’t achieve your quota and can cause substantial damage to your equipment.

“Walk away from jobs that your machine is not made for or get the equipment that is right for a certain job,” Wagner continued. “Sometimes a crushing job might look too good to let go, but a mobile impact crusher has its limits.” He explained that using the machine for the wrong application causes friction that can result in premature

wear and damage. “Consult your local crushing and screening specialist to get a second opinion and get the right equipment.”

“If the contractor is going to other sites to crush and screen material, they need to make sure they have a fully trained crew that knows how to operate and service the equipment properly in these applications,” Worley said. “This is very important to keep the cost per ton down. Also, before they move the equipment to different locations, they need to take a look at these sites beforehand to ensure the equipment will be set up properly. This includes taking a look at the pile—or piles—that need to be processed so they can have the right settings on the crusher and screen and to have it properly laid out on the site. This will minimize any ‘surprises’ that could drive your cost per ton up.”

Those surprises are something Wagner alluded to when discussing challenges for which contract crushers can plan. “The challenge is that you process material piles that you have no control over nor know very well,” Wagner said. “If you don’t process your own materials, you need to be prepared for everything. And performing proper due diligence before accepting a job is a must. Often, the big surprise is inside a material pile. Everything might look good on the outside but becomes a nightmare as soon as you start digging into the pile. To protect yourself from damages, you need to be very clear with your customer as to what you can and cannot process and what it means if you can’t process something.”

If you’ve determined that your site could support its own crushing and screening operation for recycle material with room to add contract recycle processing on the side, consider the ideas experts have suggested here to make your plans go more smoothly.

LEARN MORE LOWER WEAR COSTS Rubble Master’s René Wagner shared: “When you process large amounts of asphalt millings with a lot of fines, a mobile screen helps to reduce wear costs and increase total production. If you can’t remove fines prior to the crushing process, your wear parts get chewed up quickly, which affects your bottom line. In this case, the additional investment of a scalping screen pays for itself quickly.

“Recently, a client of ours installed a large 22-foot by 5-foot mobile incline screen to process asphalt millings with very little oversize. He screens -inch minus, and he uses a compact RM70GO! mobile impact crusher to process the little oversize that was left from the screening process.

“The same logic applies if you need large amounts of small, finished products such as ½-inch minus material. The onboard screen of a closed-circuit impact crusher might not have enough capacity and becomes your bottleneck. If you can’t screen what comes out of the impact crusher, you lose production and face higher wear costs. In this case, a screening plant after your impact crusher helps again to increase production and lower wear costs.”

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HOW TO PAVE RAP MIXES Produce consistently in the field for successful paving with reclaimed asphalt pavement mixes

T

BY BRYCE WUORI

The asphalt industry is seeing more state departments of transportation (DOTs) incorporating higher percentages of reclaimed asphalt pavement (RAP) in mix designs.

Whether your project specifies 5% or 50% RAP, there are practices you can perform in the field to produce consistency and complete a successful RAP project.

When working with RAP, the key from start to finish is consistency. Plant production, stockpile management, paver speed, roller patterns and even the milling operations from which the RAP is sourced, are just a few of the main variables that will need to be managed with great consideration. There are many more variables that must be managed correctly for success with RAP. The few listed above can be identified as more common and can take the least amount of effort to improve quality and produce consistency on your next RAP project.

CONSISTENCY FROM START TO FINISH

It all begins with the RAP source that will be used in the mix design. The condition of the RAP source can affect the consistency of the mix leaving the plant. RAP mix that leaves the plant with inconsistencies will produce problems in the field for the paving and rolling operations. The foundation to producing consistency while paving with RAP starts with the RAP source itself. Without this foundation in place the potential for all other procedures to be successful can decrease considerably.

If the RAP source is not from the existing project, further research and investigation of the material should be made prior to producing and paving. A few of the common variables that should be investigated with the RAP sources include: • depth of the milling to produce the RAP material; • age and condition of the road or RAP source being used; 40 | FEBRUARY 2022

Paving with RAP in Eastern Montana

• existing section of roadway where RAP material was extracted from; and • types of binder used in extracted road pavement.

These are just a few questions that can better determine what kind of consistency may be expected from the RAP source provided for the specific project.

If the RAP is coming from the existing road on the project, there will be a better chance at managing some of the variables that may cause future issues with the RAP material.

MANAGE MOISTURE

If the RAP source is extracted by milling operations, there are some management techniques that will assist with producing a more consistent RAP mix through the plant. Managing water during milling operations and RAP stockpile management techniques are two ways moisture can be managed when paving with RAP mixes. It is a well-known fact

that moisture in the RAP source will cause issues at the plant with production and developing a consistent asphalt field mix.

Increases in RAP moisture being placed through the asphalt plant can cause volumetric issues that may include air void variability, asphalt binder variability (chasing AC) and plant production issues. When moisture is present in the RAP source, it will naturally take more thermal energy to remove this variable which causes strain on an asphalt plant producing the asphalt mix. If the moisture is not fully removed during plant production, we can see issues in the field or develop moisture in the asphalt field mix.

When there is a high amount of moisture in the asphalt field mix, often sweat dripping from the mix trucks can be detected. This is moisture leaving the mix through a thermodynamic process and is a very good indication that there is a moisture issue at the plant or with our RAP source.

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LEFT: This tender zone appeared from moisture in the asphalt field mix. CENTER: Thermal image of 24% RAP project. RIGHT: Intelligent Compaction roller on a mill-and-fill project using RAP

Another common indication that there are significant amounts of moisture in the field mix include large amounts of steam leaving the newly laid asphalt mat behind the paver screed.

The final indication that we may be dealing with moisture in the asphalt field mix is when a tender zone develops during the rolling operations.

This tender zone typically develops within the intermediate rolling position and often requires the use of a rubber tire roller in place of steel drum roller to manipulate the mat.

Managing RAP source moisture is a very important step in producing a consistent RAP material for the asphalt plant and field operations. During milling operations, managing extraction speeds and water control can prevent the addition of excess water in the RAP source.

If hauling and stockpiling the RAP source is within your project scope, there are management procedures that can be put into place to reduce moisture as well. One effective stockpile management technique that can assist in controlling moisture within the RAP source is performing separate daily RAP stockpile locations. This stockpile technique is designed to separate daily RAP piles in an order that allows the oldest RAP stockpiles brought from extraction to be put through the asphalt plant first. This specific method allows the RAP source to dry for longer periods and with the additional surface area exposed to natural environments, individual stockpiles will dry more efficiently. Individual RAP stockpiles also allow for better management and an increased understanding of what the actual moisture of the RAP source is on the project.

42 | FEBRUARY 2022

Although this technique works well for drying and managing RAP sources, it does have some drawbacks that may include additional space in your asphalt plant yard and the possibility of requiring another payloader in the plant operations.

PAVE WITH CARE

With a good RAP source and properly managed moisture, the next step to produce consistency in the field is to concentrate on the paving and rolling operations. Setting up the paver and rollers for a RAP mix will vary from project to project depending on the scope and requirements of that specific project. There are a few techniques that seem to trend on RAP projects when setting up field operations.

Mixes containing RAP can naturally have a larger thermal gap than mixes of all virgin asphalt due to the way the material is introduced into the asphalt plant. With technologies such as paver mounted thermal profilers and thermal cameras, we can identify these areas on RAP mixes during paving operations. This thermal gap increase can cause the asphalt mat to cool down unevenly in specific areas which can potentially cause segregation or low density.

To manage this issue, field operations must keep consistent paver speeds and reduce paver stops. Finding a comfortable paver speed that allows the rolling operations to stay as close as possible to the paver will reduce these areas of potential low quality. Matching the plant production to the paver speed will increase quality, improve ride, and produce a more consistent density.

Rolling operations and patterns for RAP mix designs do not change that much from a virgin asphalt mixes. The biggest factors to remember are keeping consistent rolling patterns and allowing the rollers to be in a temperature zone that allows optimum density achievement. Technologies such as Intelligent Compaction assist roller operators tremendously with obtaining consistent patterns in designated temperature zones. Roller operators must continuously maintain patterns on the project to produce a consistent asphalt mat. If rolling operations happen to fall out of patterns or temperature zones, the margin for producing a high-quality asphalt mat will decrease. This rolling technique is especially important for consistency on a RAP project.

In conclusion, RAP is a great sustainable addition to many mix designs when constructing long lasting smooth roads. These asphalt mix designs may be more challenging to manage and place at times, but this does not imply the material is less durable or will not be as smooth when compared to conventional asphalt mixes. When working with RAP, paying attention to detail and precise operation management techniques will develop consistency in the field. Developing consistency in the field starts from the beginning and must be followed through to the end to be effective when paving with RAP. Bryce Wuori is the owner of Wuori Consulting and the developer of PaveWise™ and Dynamic Density Design. He studied construction engineering at North Dakota State University and holds a Master of Project Management.

For more information, contact him at bryce.w.wuori@gmail.com.

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SMART INSPECTIONS

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A look at the future of stockpile inspections for the aggregates industry

BY KRISHNAN HARIHARAN

The global commercial drone market size was valued at $13.44 billion in 2020 and is expected to expand at a compound annual growth rate of 57.5% from 2021 to 2028. This means major industries are quickly adopting the use of commercial drones, and the aggregates industry is no exception.

Industrial drones leverage the power of aerial intelligence and machine learning to increase data accuracy while reducing the time workers spend collecting and analyzing data.

The benefits of smart inspections are applicable to the aggregates industry because drones have proven highly accurate when it comes to data collection, and their technology is frequently paired with advanced ML/AL algorithms.

Smart inspections allow the aggregates industry to perform hands-free inventory inspections in drastically less time by using drone technology, machine learning, AI, high-resolution imagery and cloud-based analytics. With smart inspections, aggregates managers don’t need to climb on stockpiles to take measurements for inventory. Instead, an AI-powered drone can do it for them. All they have to do is tap out a flight perimeter on a tablet, and the drone will fly the path and send captured aerial images and data to the cloud for analysis. After the worker merely had to man the tablet for a few minutes, the drone will land on its own.

SMART INSPECTIONS MEAN INCREASED ACCURACY

Drone manufacturers are constantly improving upon how their instruments fly and collect and analyze data, thanks to the power of AI and machine learning. These drones also can gather high-resolution videography and aerial imagery that is so accurate, it can even account for the slope of a stockpile, ensuring measurements are as spot-on as possible.

Even the best of us make mistakes. That’s why traditional forms of stockpile inventory measurement contain human error. With smart inspections, aggregates managers can be certain their data is as perfect as possible, with accuracy typically in the 1-3% range.

44 | FEBRUARY 2022

TECHNOLOGY PRIORITIZES WORKER SAFETY, EFFICIENCY

After lugging a shaky ladder up a stockpile, have you ever stopped to ask: With all the technology available to us today, why are we still performing stockpile inspections manually?

When aggregates managers climb stockpiles, it’s not only dangerous, but also a liability.

Saving time is an additional perk to adopting smart inspections. After an employee selects a flight perimeter for the drone, the drone handles the rest and collects the data it needs in mere minutes. Then it uploads said data to the cloud for analysis by all who need it.

Drones are also a speedy choice because they can fly faster than humans can move, and they can also access areas that aren’t safe for people. For example, if a stockpile is steep and has tumbling materials in a specific area, the worker would have to really think about the best way to get to that location for measurement. This not only puts the worker in danger, but it wastes precious time. Meanwhile, if the worker had a drone, it could quickly fly right over the dangerous area and gather the data and imaging necessary.

Another speedy perk of smart inspection is that the drones share the data quickly, in addition to completing stockpile inspections in record time. Once the drone is finished with its flight, it sends the data it gathered to the cloud so that the aggregates worker has it within minutes, and the rest of his or her team can review it at the same time. This means teams can collaborate on and off-site, and speedy decisions about the inventory data can be made.

SMART INSPECTIONS ARE THE FUTURE

Aggregate companies have a unique opportunity when it comes to autonomous drones.

They not only increase accuracy of stockpile measurement and keep employees safe, but they also save a significant amount of time.

Smart inspections are the way forward when it comes to stockpile inspections.

Krishnan Hariharan is the CEO of Kespry, Menlo Park, California, a leader in touchless, drone-based aerial intelligence.

CENTRAL PLANT RECYCLES IT COLD

V

VDOT can rely on a decade of experience using cold central plant recycling to rebuild its interstates. In 2011 the commonwealth completed an in-place pavement recycling project on I-81 near Staunton in the foothills of the Blue Ridge Mountains. That project consisted of a 3.66-mile section of southbound I-81 in Augusta County. And most recently, in 2021, CCPR was used on the reconstruction of I-64 in the Hampton Roads region.

On I-81, VDOT employed three in-place pavement recycling techniques—full-depth reclamation (FDR) and cold in-place recycling (CIR) using Wirtgen mobile equipment, and CCPR using the Wirtgen KMA 46 | FEBRUARY 2022

BY TOM KUENNEN

220i mobile cold recycling mixing plant.

That project marked the first time in the United States that these three recycling techniques were combined in one project on the interstate system.

FDR is an engineered rehabilitation technique in which the full thickness of the asphalt pavement and a portion of the underlying materials are uniformly pulverized and blended to provide an upgraded, homogeneous material in one pass. The reclaimed materials may be improved and strengthened by using mechanical, chemical or bituminous stabilization, the latter via foamed asphalt or asphalt emulsion.

CIR is a surface process in which specialized equipment cuts the top 3 to 5 inches or more of an existing poor quality pavement surface, grinds and resizes the reclaimed asphalt pavement (RAP), mixes it with foamed asphalt or asphalt emulsion binder, and replaces it in the right-of-way, ready for compaction and surface treatment or overlay.

With CIR, Virginia calls for a typical depth of 3 to 5 in. and stabilizes the material with either foamed asphalt or asphalt emulsion.

CCRP involves RAP that has been crushed and screened and brought to a cold recycling plant like the KMA 220i to create a foamed-, asphalt emulsion-, or cement or

lime slurry-stabilized base material, which is trucked out to a reconstruction site.

VDOT uses CCPR to create structural base material placed to a depth of 3-6 inches, specifies foamed or emulsified asphalt as a stabilizer, and uses it as an alternate to deeper mill-and-fill/partial depth patching.

“The I-81 in-place pavement recycling project was completed quickly and cost-effectively,” said the Virginia Transportation Research Council (VRTC) in 2014. “Because of its engineering excellence and innovation, the project earned several prestigious national awards. Nearly three years of good performance proved the success of the pavement produced with these in-place recycling processes. The surface and deep structure of the rehabilitated section are expected to remain sound for years to come.”

CCPR FOR VIRGINIA’S I-64

Its success in using all three asphalt recycling techniques in reconstructing I-81, and its performance for years thereafter, led to VDOT's use of the three techniques in an ongoing three-segment rebuild of I-64.

There, in Segment III, the Wirtgen KMA 220i is producing more than 220 tons per hour of foamed asphalt structural base for the I-64 rebuild, and the entire process spotlights the manner in which VDOT reconstructs its high-volume highways in an environmentally sustainable manner.

In 2021 the I-64 Capacity Improvements Project work was in Segment III of a three-segment project to improve traffic flow in Virginia’s Tidewater peninsula. Improvements include replacement of existing lanes, the addition of 12-foot-wide travel lanes in the median, and new 12-foot-wide shoulders in each direction.

The $178 million Segment III is 8.2 miles long and, according to VTRC, with the earlier two segments, constitutes one of the largest pavement recycling initiatives in North America and second largest in the world.

Recycling will result in an estimated $15 million cost savings total for Segments II and III. Over the course of the I-64 widening projects, it’s estimated that nearly 1.2 million tons of recycled materials will be used.

From the bottom, the Segment III section design is 12 inches of FDR, a 2-inch asphalt open graded drainage layer, 5-in. of CCPR from the KMA 220i, and 4-in. surface course of stone matrix asphalt (SMA).

Allan Myers Inc. was prime contractor for Segment II, and was the CCPR and asphalt placement subcontractor for Segment III. While state specs say Allan Myers

LEFT: At Allan Myers' HMA facility, the Wirtgen KMA 220i portable plant will operate in stationary mode for some time to come. Raw, processed RAP is fed into plant for foamed asphalt. ABOVE: Plant mechanic Steven Morris, operator Gage Browning and quality control manager Craig Rayfield tend the KMA 220i portable cold recycling plant at Allan Myers’ New Kent, Virginia, HMA facility.

They start making foamed asphalt base mix early in the morning, prepping it to ship out to I-64.

WWW.THEASPHALTPRO.COM | 47

Gage Browning, plant operator, at the controls of KMA 220i.

“The KMA 220i is ... great for the environment, because we have a mountain of unprocessed RAP that we now have something to utilize it with,” Craig Rayfield said.

The cold central plant recycles RAP into foamed asphalt at full capacity for owner Allan Myers for use on the I-64 project.

48 | FEBRUARY 2022

could have used its KMA 220i to stabilize the CCPR using asphalt emulsion, instead it chose to use foamed asphalt for Segments I, II and III. Foamed asphalt or bitumen incorporates liquid “foamed” asphalt as a recycled mix stabilizing agent for bases or FDR, in which hot liquid asphalt is foamed with water and air, and is then injected into RAP in a mixing chamber, in a portable plant, or a self-propelled recycler/reclaimer. This permits use of less liquid asphalt and lower mixing temperatures, which benefits the environment. Depending on the degree of presence of fines in the existing materials to be recycled, up to 1 percent cement or hydrated lime may be required to act as a carrier or “dispersing agent” for the liquid asphalt to assist its spread throughout the pulverized material.

“The KMA 220i is easy to run, so long as you keep up with the maintenance and the clean-up,” said Steven Morris, KMA 220i plant mechanic for Allan Myers. “You keep on top of your cement and make sure all the feeders are feeding. You make sure all the skirt rubber is cleaned up and that the weigh bridges are clean; that way it reads correctly.

“On start-up, getting your base line is a little tricky because you have to work with your lab,” Morris continued. “But after that, it’s pretty much plug and play. As long as everything’s running steadily, it’s a smooth operation but with walking around and checking everything, keeping your water full.”

The foamed asphalt mix design was prepared by Stephanie Drain P.E., Charleston, Illinois, and Wirtgen’s Mike Marshall.

“We have between 80 and 85 percent RAP, around 14 percent No. 10 screenings,” said Craig Rayfield, quality control manager for Allan Myers, Williamsburg, Virginia. “We have 2.5 percent liquid asphalt, and 1 percent Portland cement.”

The performance-graded asphalt cement for foaming is PG64-22 spec, and for the mix a moisture specification is maintained to assist compaction. Unlike the I-81 project—in which RAP was coming off the job site, foam-mixed, and returned to the site— in this project, existing stockpiled RAP from different jobs was being used.

“We have RAP from all over the area,” Rayfield said. “When that RAP arrives, it’s unprocessed. A contract crushing company processes the material to 1/2- to 3/8-inch size, which pretty much gives us about a hundred percent passing the half-inch sieve.”

Because the RAP comes from different job sites, it varies in residual asphalt

CRUSH RAP COSTS with the

HONEY BADGER From replaceable abrasion-resistant steel wear liners to a 1/2" steel pulverizing hopper, this machine is ready for wear and tear. And by reducing material handling and minimizing moisture, the Honey Badger increases production and saves on fuel costs. Average return on investment is 1/8 the cost of other crushing operations.

Fully-equipped with max power, reliable operation, and easy maintenance, the Honey Badger is ready to crush your costs!

Reduced RAP moisture = lower fuel consumptions Reduce or eliminate crushing costs Typical 6 month ROI (300,000 ton/season plant)

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content, which will affect the foamed mix design. To get around that, the stockpiles are blended so they will produce a RAP with a reliable, consistent average percent residual asphalt.

“The processing takes the RAP and blends it into a homogenous mix of a certain particle size range,” Rayfield said. “Then our lab technicians will pull samples to run gradations and asphalt contents. That way we have an idea of what’s going into the product, and we can control it.”

50 | FEBRUARY 2022

STATIONARY MODE

While the plant is mobile—the KMA 220i is mounted on a three-axle flatbed trailer— Allan Myers’ KMA 220i is in a stationary location at its New Kent, Virginia, hot-mix asphalt (HMA) plant just off I-64 and west of the three segments.

“The plant is portable, but I would say it’s ‘semi-stationary’ right now,” Rayfield said.

“We’ve added larger asphalt tanks, up to 22,000 gallons total, for highest production capacity, and a larger cement silo for bet-

ter production. And we have a 5,000-gallon water tank on the back side, eliminating the need to hook into a water line or well system. It wouldn’t take much effort to get it portable again, and we can move it if we want to, but we have no need to now.”

Planned VDOT reconstruction segments for I-64 may mean the KMA 220i stays where it is indefinitely. “It’s in a very strategic location right now,” Rayfield added.

A typical shift of 9.5 to 10.5 hours will produce 1,600 to 1,800 tons per day of foamed asphalt base mix. “These guys get here at 4:30 in the morning, and run up to 700 tons on the ground; we then start shipping and the plant keeps up with it the rest of the day,” Rayfield said. “We’re looking at 27,000 more tons to finish the project, with a total forecast of 170,000 tons of cold central plant recycled foam mix.”

Foamed asphalt may be stockpiled for a few days, but Allan Myers found moisture loss over 24 hours impacted compaction in the field. The contractor even erected a shelter with sprinkler system that could hold the mix longer while maintaining moisture. “But we found that we’re better off just coming in early and making the mix, and let it sit a couple of hours before placement, rather than try to hold it for 24 hours,” Rayfield said.

Back in Segment II, Allan Myers had to get used to the plant and production of foamed base mix.

“When this product came here originally, a lot of us were skeptical,” Rayfield said.

“We were shy of it, but it didn’t take long to figure it out.”

“It's clean, it doesn’t smoke, and it doesn’t smell,” Morris said. “It has no pollution.

We can run a whole day shift on less than three-quarters of a tank of fuel, which we calculated as 10.2 gallons per hour.”

“That represents a huge savings, along with the amount of RAP that’s going into it,” Rayfield added. “As far as being effective and efficient, it’s very cost-effective. At Allan Myers, if there’s a way we can do something better, or be innovative, we jump on it. We tackled the challenge, bid the job, and got the information we needed to design the mix. It’s been smooth sailing ever since.”

And while the 220 tons per hour that the Wirtgen plant can produce is adequate, Rayfield could use even more volume.

“We could use a bigger plant,” he said.

“The 220i’s capability is limited as far as its tons-per-hour, but it’s given use what we need to perform. But if we could run 300, 350 tons per hour we could ship even faster.”

LEADING ASPHALT TRADE SHOW AND CONFERENCE “This was my first show and it was a great experience. Being able to see and talk with all of the vendors within our industry was a huge benefit for my current position and professional growth.

I now feel as though I have a better understanding of our industry and what vendors are available as well as technologies. This adds excellent value to our organization.” — Jamie Bailey, Lehigh Hanson

March 29-31, 2022 | Nashville, Tennessee Register for tickets at worldofasphalt.com

I N T E R N AT I O N A L S N A P S H OT

Puma Bitumen Adds Sustainability in Australia

BY ROADS & INFRASTRUCTURE STAFF

I

ncorporating liquid warm mix additives into the binder is a common process in warm-mix asphalt (WMA) production with far-reaching benefits, from lower energy demand and emissions during asphalt production, increased allowable haul distances, and increased workability and compaction during construction. Of all the benefits that warm mix additives offer to the mix, Puma Bitumen Global Technical Manager Erik Denneman said their impact on asphalt durability by minimizing bitumen aging is often overlooked—but it offers the most sustainability outcomes.

To elaborate this further, Denneman offered a short overview of how asphalt binders age with time. “Asphalt binders are made of organic molecules, and they age when they react with oxygen from the environment,” he said. “Most of this aging happens during the production, transport and the laying process because it occurs at elevated temperatures. We know that under hot mix conditions, the majority of the aging process takes place during the manufacturing, transport and placement phase. So, in effect, a large part of the oxidation life of the binder is consumed by the time the bitumen is used in the field.”

Therefore, using WMA not only reduces emissions and energy consumption during production and construction, its use can also lead to more durable roads, with longer phases between maintenance requirements, thus lowering a road’s carbon footprint overall. This is quite possibly the most important contribution of WMA to improving sustainability of the product, Denneman said.

BIO-BASED ANOVA

Working closely with Cargill, the global manufacturer of Anova asphalt products, Puma Bitumen recently introduced the Anova warm mix additive and the Anova asphalt rejuvenator to its market. Denneman said before choosing Cargill’s Anova product line, Puma Bitumen researched to find proven asphalt products with demonstrated performance history.

52 | FEBRUARY 2022

Photo courtesy of Cargill

“We were looking for a warm mix additive that was completely safe from a health and safety perspective and that is how we ended up with the Cargill product,” Denneman said. “Cargill’s Anova product line has a significant track record, especially in the U.S., where it has been approved for use in 20 states. So, we did not have to reinvent the wheel, all we had to show was that it worked with the bitumen and rock sources we use here in Australia.”

Denneman said the fact that the Anova warm mix additive is made with biobased ingredients means it is non-toxic and non-corrosive. “Puma Bitumen, as a company, always has sustainability front of mind and we aspire to play a leadership role in this space. One of the benefits of the Anova warm mix additive is that it’s a vegetable derived product, so it is nonhazardous. As far as operational health and safety is concerned, it ticks all the boxes,” Denneman said.

“We also undertook extensive laboratory testing, including compaction testing, to

demonstrate that the temperature reduction achieved with Anova was at least on par with that obtained using wax or aminebased warm mix additives. We performed a range of binder tests to show that Anova did not negatively affect the performance of the paving grade bitumen or polymer modified bitumen (PMB),” he added. Further, Denneman said the Anova warm mix additive is also very cost competitive.

“The dosage rate of the Anova warm mix additive is comparable with that of aminebased warm mix additives, that is around 0.3 to 0.4% of the binder content. Comparatively, wax-based additives are typically used at higher dosage rates...”

Puma Bitumen also offers a special service to its customers, which is to provide binders pre-dosed with Anova additives at Puma Bitumen terminals, eliminating the need to handle warm mix additives at the asphalt plant.

“Normally, customers have to add the warm mix additive themselves, which can be cumbersome,” Denneman said. “By giving

them the option to select binder pre-dosed with Anova at Puma terminals, we give them the peace of mind that the bitumen properties are controlled and provide the best performance.”

Puma Bitumen started first demonstrations with the Anova warm mix additive in September 2020 at its plant in Victoria, with the product now offered across all of Puma Bitumen’s terminals Australia-wide.

ANOVA’S HISTORY

Hassan Tabatabaee, global technical manager – Asphalt Solutions at Cargill, explained how Cargill developed and demonstrated performance of the Anova product line. “As a company with over 150 years of manufacturing experience, Cargill is a pioneer in finding ways to sustainably use agricultural products to create unique chemistries for industrial applications,” said Tabatabaee, who has a doctorate degree in pavement materials. “The Anova product line was born out of that concept and as we started experimenting with different types of bio-based materials, we initially launched a rheology modifier and then further expanded the product line to include recycling agents or rejuvenators, warm mix additives, cold mix additives, anti-stripping agents, and emulsifiers, growing Anova into a broader portfolio over the past seven years.”

The Anova asphalt rejuvenator, Tabatabaee said, is a stable liquid additive that offers flexibility to asphalt terminals, allowing for using up to 100% reclaimed asphalt pavement (RAP) in HMA, while also aiding in compaction. “What makes the Anova asphalt rejuvenator product unique in the industry is the extent of its demonstrated history, not just in the U.S., but globally,” Tabatabaee said.

“When this product was first brought to the market around six years ago, we started trialing it with varying percentages of recycled content across the east coast of the United States. East coast regions like New York City and New Jersey have a very high population density and are therefore very conscious about managing their material stockpiles, especially of recyclable materials like RAP. Since they have excess RAP available, we were able to use the rejuvenator for 50, 60% or even higher recycled content and we got great results in terms of performance.

“Almost concurrently, we also started trials in the Netherlands, which is very flat and has little access to local aggregates, so resource management is again very critical. We started looking at 70% recycled content and

very quickly went up to 100%. Within a couple of years, we were doing millions of tonnes of pavement with high recycled content in North America and in Western Europe using Anova rejuvenator.”

Independent testing at test track facilities in North America complimented the trials, he said. “In order to have independent demonstration of the results, we worked with two leading test track facilities in North America, the National Center for Asphalt Technology (NCAT) in Auburn, Alabama, and the Minnesota Research facility (MnROAD) in Otsego. These facilities work very closely with each other in terms of studying real world pavements and trafficking, but with independent monitoring of the conditions, one in hot climate and one in cold, wet climate.

“We put down sections with high recycled content, about 45%, in both regions and about three years later they have gone through a full cycle at both facilities. We have now surpassed 10 million loading cycles on the NCAT test track, which is pretty much the life cycle of a very busy freeway. There has been zero cracking reported so far, which is some very powerful data coming from these nationally recognized centers,” he added.

The aging stability is also critical where high percentage of recycled asphalt is used in the mix. “The other part, which was really a big aspect of our product development, was putting a unique emphasis on aging stability. It was important for us that our product not just helps on day one, but that pavements with high recycled content have a long, healthy life on par, if not longer, than what you would expect from a pavement with low recycled content. That unique aging resistance is a big aspect of how we position the value of the Anova asphalt rejuvenator product with customers.”

TWO BRANDS

Both Tabatabaee and Denneman agreed that the synergy shared between Cargill and Puma Bitumen is the secret to the two companies’ successful partnership. “Our partnership with Puma Bitumen has been quite gratifying and unique,” Tabatabaee said. “Both our companies have a broad approach to how we serve the pavement market. Puma Bitumen has been very innovative and open about how they bring value to their customers. They are also always very transparent, both with their customers and with partners like us. That’s something that we as a company value a lot,” he added.

With Cargill’s brand strategy focused on helping the world thrive, Tabatabaee said sustainability is at the core of the company’s products. “Sustainability has been a core value to the Cargill business, not just because it’s become trendy, but because it is in the company’s culture. With Cargill’s tagline around ‘thriving’ communities, we certainly understand the need for a healthy environment and sustainable resource management. Cargill knows that, across industries, manufacturers are looking for smarter ways to formulate their products to improve performance and/ or gain cost efficiencies.

“We develop our bio-industrial solutions to meet our customers’ needs in a responsible, sustainable manner by using renewable feedstocks, while also contributing to farmer prosperity and improving farmer livelihood.

Puma Bitumen, as a global company, shares those values with us and it has been an important angle in our relationship.”

Denneman said Puma Bitumen’s existing product portfolio and the mix it brings to the market is a good indicator of the company’s position on sustainable pavements. “Our range of high performance, storage stable PMBs, which are very well known for their quality and consistency, help to create more durable pavements. We also offer consistent EME2 binders that allow construction of thinner pavements, further assisting with pavement sustainability.

“More recently, Puma Bitumen has also introduced GB5 base course mix, which is an alternative to EME2, allowing the use of even less bitumen in pavements. On the recycling side, we have a range of waste tire derived crumb rubber binders ranging from the normal spray sealing grades to more specialty binders and our latest OLEXOCRUMB® hybrid binder which contains both tire derived rubber and styrene-butadiene-styrene (SBS).”

The latest addition to the family follows the same sustainability strategy, Denneman said. “The research and development part of Puma’s business is squarely focused on bringing more sustainable products to the market. “Puma Energy has committed to carbon neutrality by 2030 and we want to help our customers achieve the same. Cargill’s Anova asphalt solutions fit that objective like a glove.”

The original version of this article was published in Roads & Infrastructure magazine; visit roadsonline.com.au for more stories about the Australian market.

WWW.THEASPHALTPRO.COM | 53

P R O D U C T GA L L E RY

Optimize Your Production Veil

BY ASPHALTPRO STAFF

T

o kick off this month’s production-related product gallery, let’s take a look at the dryer drum. While producers will peruse the following pages for aggregate and asphalt production services and products, they can get a drum tip right here from BROCK, headquartered in Chattanooga. That tip focuses on flighting to optimize the veil of material in the drum.

Working with consulting engineer Malcolm Swanson, BROCK offers the FlexFlight™, which Swanson designed and for which he has applied for a patent through his company, e5 Engineers LLC, Chickamauga, Georgia. The FlexFlight is designed to address the fundamental challenge of executing a proper shower of material within the rotating drum.

By controlling the shower—or veil—of material in the drum as you change mix designs and/or production rates, you can also control temperatures leaving the drum. Swanson explained: “When you need a good complete veil most, as with open graded mixes and high RAP mixes, the veil is thin or nonexistent on the uplift side of the drum. So, hot gas bypasses material by taking the path of least resistance through the gap in the veil.” To get a more even veil of material for hot gas to spread evenly across, you want flights to “spill” material properly, evenly, and in a reliable fashion even when there isn’t much material in the flight.

“Conventional flights shower differently depending on fullness,” Swanson said. “When very full, they tend to allow material to cascade out early, making the uplift side of the veil too heavy. When they contain little material, as is the case with high RAP mixes, they tend to shower little or nothing on the uplift side and dump what they do have as they start back down. FlexFlight is designed to restrict flooding when full and yet allow showering even when nearly empty.”

Producers and manufacturers alike have long known the benefits of good showering in the dryer. Some of these benefits are higher production capacity, better fuel efficiency, more uniform and thorough drying of aggregates, better control of baghouse temperature, the ability to make higher RAP mixes that could not be made without excellent showering, and lower emissions. Swanson explained that manufacturers have, for many years, made flights that incorporate gaps to address the fill percentage or to prevent flooding of the flight with material, but the gaps have not always been good at allowing material to build and spill efficiently.

Instead, the gaps have often allowed aggregate to dribble out.

The FlexFlight design doesn’t incorporate a gap but has a completely surrounded opening with several inches width at its bottom to prevent dribbling. “The opening is centered lengthwise, so you get a good veil at all parts of the circuit,” Swanson said. You can see the design in the photo on this page.

To configure the flights in the drum, they are placed in the drying zone according to the needs of the producer. See the photo on this page for an example of how Ranger Construction has theirs configured. “Going forward, we probably will use a number of flights per row that is a multiple of the drum diameter in feet,” Swanson said.

“For example: if a 9-foot drum needs 54 new flights, it could get two rows of nine and two rows of 18 flights. That makes it a bit more rational for direct replacement in existing drums, since this is a pattern of flighting often used by dryer manufacturers.”

For more information, contact e5 Engineers at malcolm@ e5engineers.com.

54 | FEBRUARY 2022

Ranger Construction uses the FlexFlights in the drying zone of their 9-foot Double Barrel drum. Also called the showering zone, this is where the heavy lifting of drying and heating is done. There were four rows with 14 flights per row. Swanson explained the number of flights per row will vary according to the producer’s needs. Photo courtesy of Malcolm Swanson, e5 Engineers

The FlexFlight, designed and currently in patent-pending status by Swanson’s e5 Engineers, is available through BROCK (www.brock.llc).

AMMANN

Ammann Group offers the Ammann RAH50 drying drum retrofit to improve fuel efficiency and recycling capabilities over old drying drums.

Ammann drying drum retrofits are designed to be compatible with equipment from Ammann or other manufacturers. Ammann dryers heat and dry raw materials of different compositions, material properties and moisture contents. They have exceptional wear resistance, are easy to maintain and highly efficient, according to the manufacturer. The Ammann RAH50 is a popular retrofit because it allows customers to work with recycled asphalt.

Christian Westphal, head of machine technology MTA Mischwerke SAW Schleswiger Asphaltsplitt-Werke GmbH & Co. KG, retrofitted a plant with an Ammann RAH50 drum. He explained how his new middle dryer ring works compared to a conventional new mineral drum.

“At first, I was rather skeptical because of the promised high RAP addition rates (up to 45%),” Westphal shared. “The promises have been kept regarding flexibility and RAP addition. The maintenance effort is, of course, slightly higher than with a pure new mineral drum, but it is lower than previously expected. Surprisingly, RAP caking is not a problem at all.”

Westphal spoke of the drum’s different applications. “In addition to the standard cold feed, the RAH50 drum gives us the flexibility to switch to hot recycling. It is already worthwhile for us to use the RAH50 middle ring addition from batch sizes of 50 tonnes. Switching to hot recycling is problem-free, taking into account the overrun from the dryer drum to the hot mineral silo. For permissible construction measures, RAP percentages of up to 45% are possible for base layers via the middle ring addition. This enables us, in consultation with the client, to recycle large quantities, which of course offers enormous advantages in terms of costs.”

Westphal also spoke of temperatures. “The addition of RAP to the RAH50 drum enables gentler heating compared to cold addition.

When mixing the raw material with the RAP, we can run drum outlet temperatures of 160 to 170 degrees C. This is gentle on all plant components and also saves fuel. The frequency converter installed in the drive motors also allows us to vary the dwell time of the new minerals and the RAP, which means that all types of aggregate are dried very effectively.”

The Ammann dryer drums also offer wall thicknesses up to 15 mm and a frequency converter for energy-efficient operation. The drums are available with Amdurit wear protection and high-temperature steel.

For more information, visit www.ammann.com

ASTEC

Quick setup of durable equipment makes the Astec M-Pack™ relocatable facility an excellent value, according to manufacturer Astec Industries, Chattanooga. The plant has the capacity and size of a permanent facility with reduced setup costs. It is engineered as a set of modules that are transported by truck. Each Astec M-Pack plant ships in ready to set up loads when it leaves the manufacturing facility. Level and pave your site, then lift the pre-piped, pre-wired modules off the trailer and bolt them up. The M-Pack foundations are heavy-duty and designed to provide plenty of load-bearing surface to support the facility components. If you ever have to move to another site, most loads fit on lowboy type trailers, and the built-in foundations go with them.

The Astec M-Pack asphalt mixing plant is engineered as a set of modules that ship in ready-to-set-up loads when it leaves the manufacturing facility.

High production, large storage capacity, full-size control rooms, high-quality components, and excellent maintenance access make the modular Astec M-Pack asphalt mixing plant highly functional, according to the manufacturer. This asphalt mixing plant is outfitted with the latest technology and proven Astec performance. There are a wide range of options on these plants: • Astec offers four exclusive mixing systems: Double Barrel, Double Barrel X, Double Barrel XHR or UniDrum • Astec offers two full-size silo options: Long-Term or Short-Term • Astec offers two baghouse options: Pulse Jet or Reverse Pulse With a team of experienced engineers and in-house technicians, Astec has the knowledge and the expertise to help you make the appropriate selections to meet your requirements.

For more information, visit https://www.astecindustries.com/ products/details/m-pack-asphalt-plant.

BROCK

BROCK, Chattanooga, has signed an agreement to have booth 1976 at the World of Asphalt/AGG1 Show to be held in Nashville, March 29-31, 2022. This will be the first trade show for BROCK as a company. Ben Brock, president and CEO, said, “Our average years of successful experience in hot-mix asphalt equipment per employee is now among the highest in the United States, if not the highest, so it is only natural that our first trade show is this show.

We are excited to see all attendees at the show. In the meantime, we welcome our current and potential customers to visit our facility in Chattanooga over the winter—or, since Chattanooga is just two hours from the show site, visit us either before or after the show dates.”

For more information, contact Travis Sneed at (423) 476-9900.

CLARENCE RICHARD

Steve Klein of Clarence Richard Company shares how to make aggregate stockpiles drain faster. Adding a tile drainage system under the pile area will help. Klein shows the math on why moisture is important to track—and drain. He wrote: “With the change from 6% to 5% the fuel 2.11-1.88 or a 0.23 gallon per ton difference. That’s 23.27 gallons in a hundred tons of production. Example: A plant is making 200 tph of hot mix with a fuel cost of $6.34 per ton at $3.00 gal. Reduce the stockpile from 6% to 5%. Now the cost per ton is $5.64 a ton. This is a $139.62 savings per hour from just the moisture reduction.”

WWW.THEASPHALTPRO.COM | 55

P R O D U C T GA L L E RY

The bolt-on batcher from CWMF features a heavy-duty material splitter and outward opening gates.

Watch animated video demonstrating the unitized asphalt tank heater from PHCo at booth #3119 at World of Asphalt.

CWMF

tems. Common products that benefit from electric heat include asphalt, light and heavy fuel oils, diesel, bio-diesel, glycerin, lube oils, hydraulic fluids, resins/epoxies, animal fats, molasses, and other materials that are sensitive to high temperatures.

For more information, call (866) 682-1582 or visit www. processheating.com.

CWMF, Waite Park, Minnesota, has introduced its patented innovative batcher design that allows you to service your gates without removing the batcher. The bolt-on batcher is standard at 4 tons with optional extensions for increased capacity and large access doors on two sides. All components are external and gates are removable.

With a heavy-duty material splitter and outward opening gates, the batcher is designed to minimize segregation by dropping material to the center of the silo, preventing cone/can wear.

For more information, visit www.cwmfcorp.com.

MAJOR

MAJOR, a Haver & Boecker company, headquartered in Candiac, Quebec, introduced in October its FLEX-MAT ID Enabled. The RFID technology tracks and stores screen media data such as panel dimensions and customer-defined details to offer users information at their fingertips for simple reorders. Operations scan the FLEXMAT panel with the MAJOR app to access product information, simplifying re-ordering and inventory management. MAJOR can also program the chip during production with some customer-defined information to improve convenience. Unlike some systems, users just need their smartphone to view the data and don’t need to use a separate RFID reader.

For more information, visit the MAJOR website.

PLANTDEMAND

PlantDemand, Bay Area, California, gives your team a live, cloudbased, shared calendar to organize sales scheduling and improve visibility of what is coming up at your plant. This allows you to plan material needs with your suppliers, organize your crew shifts, identify potential issues with production and strategize with customers.

PlantDemand reports are available to gather information quickly to create material need and cost forecasts, sales and revenue forecasts, or send out daily dispatches for all of your plants at once. Because PlantDemand is available in the Apple App Store and the Google Play Store, you can check and update your plant schedules while on-the-go.

PHCO

Visitors at World of Asphalt in Nashville will have an insider’s view when they visit Process Heating Company (PHCo), headquartered in Seattle, at Nashville Music City Center, booth #3119. Unique animated videos show how PHCo’s products work, effectively illustrating what sets the company’s Lo-Density® drywell-style electric heat apart from fossil-fuel burners. From PHCo’s unitized asphalt and industrial tank heaters, hot oil circulation heaters, and all-in-one heaters, to its unique distributor truck tank heaters, visitors will discover how PHCo’s simple, clean heat source can positively affect their operations.

Process Heating Company has almost 75 years of experience in manufacturing Lo-Density low-watt-density electric heating sys56 | FEBRUARY 2022

PlantDemand allows the user to create a custom dashboard with data you find most valuable.

With the new addition of an API, one can integrate documentation to create custom dashboards with other important company data or software. While there are many options when it comes to integration, a simple approach is to give people the ability to query their data and let them configure it in a way that works best for their goal.

User experience design and user interviews have helped guide improvements from the beginning and continue to be a reason plant people find the upgrades so useful. PlantDemand launched their new redesign in 2021. Based on the user feedback, some of the implemented powerful new features are these.

• A highly optimized order calendar view with search and filtering functionality • The ability to move and copy orders between plants • Settings page and user management updates • Customize required fields when entering an order • Invite multiple users at once • Enter detailed plant settings • Simplified notes.

Also, a pilot demo for paving teams to schedule paving projects is now available on the web version of PlantDemand.

For more information, visit www.plantdemand.com.

WEM

Identify opportunities to fine tune your asphalt plant production, mix quality and overall operational efficiency with WEM Analytics, a web-based software platform that can be accessed and utilized remotely via a smartphone, a tablet, or a computer, from WEM Automation.

WEM Analytics employs a drag n’ drop interface that lets you create additional customized dashboards to monitor functional areas of your plant, across various time spans (year, quarter, month, week, day, shift, and hour). Use it to compare multitiered data, with the ability to dive deeper into additional details on items such as mix production, AC usage, aggregate consumption, waste, plant alarms, and overall plant output.

The data that populates WEM Analytics’ dashboards is accessed from your WEM Automation Control System and comes with the ability to be exported in various file formats.

For more information, call (262) 782-2340 or visit WEM@ WEMAutomation.com.

WEM Analytics data can be accessed remotely from your smartphone, tablet or computer.

WWW.THEASPHALTPRO.COM | 57

O F F T H E M AT

Infrastructure Law Presents Construction Opportunity

BY TARUN NIMMAGADDA

I

n addition to serving as the largest investment in roads, bridges and passenger rail in more than a half-century, the Infrastructure Bill recently made law represents the largest federal investment in public transit, clean drinking water and wastewater infrastructure in American history. S&P Global Ratings estimates that the bill would lift productivity and economic growth, adding $1.4 trillion to the U.S. economy over eight years.

Federal agencies will receive the majority of funding and be tasked with implementing the legislation, including the disbursement of funds. State and local officials will be held accountable in designing and building the assets, tracking the funding sources across projects, and hiring additional workers to complete the jobs. The issue that the heavy building materials and construction industries face right now is recruiting enough additional workers to complete the work.

FIND SKILLED LABOR

The crippling worker shortage has been a long-standing industry issue that has been further exacerbated by the COVID-19 pandemic.

Nationwide, 92% of contractors report “moderate to high levels of difficulty” finding skilled workers, according to the U.S. Chamber of Commerce’s quarterly construction report. More than a third of the participants in the research study also report having to turn down work due to labor deficiencies.

While it’s estimated that the Infrastructure Bill will create 2 million jobs over the course of a decade, it’s also estimated that the industry could face a shortage of at least 2 million workers through 2025, per data firm, Construction Industry Resources. This poses a challenge to filling these new job opportunities and delivering on the expansion of the nation’s infrastructure. Check out the deep dive into immediate and longterm workforce development ideas in last month’s edition of AsphaltPro.

LAGGING CONSTRUCTION PRODUCTIVITY THREATENS SUCCESS

A shortage of labor inflicts challenges on this ambitious Infrastructure Bill, but there’s good news and there’s bad news.

The bad news is fixing the worker shortage is not going to come overnight, and it might not even come within the next decade. The good news is companies can turn to the use of technology to make the process of building new infrastructure more efficient, cost-effective, and to reduce—where possible—the amount of labor required to complete these projects.

There’s been a productivity lag in the construction industry for decades—one that costs the global economy $1.6 trillion annually.

Lack of technological advancements, lack of communication, coordination issues, and an inefficient use of time are all issues that serve as the Gordian knot in construction productivity. Technology can cut through the complexities.

58 | FEBRUARY 2022

Within supply chain processes, communication is key to success.

If materials show up to the job site and construction personnel are not ready to receive or use the materials, work can be delayed or come to a halt. If materials arrive on time but do not meet the project specifications, additional deliveries have to be dispatched and construction teams will be idled as they wait on replacement materials.

With improved communication, materials are easily located and on track for use at the right place for the right operation; and clear visibility into traceability of material properties and orders ensures that products arrive in the best possible quality, reducing delays and productivity lags.

TO CLOSE THE GAP BETWEEN TRADING PARTNERS ON PROJECTS, ALL INDUSTRY PLAYERS NEED TO GO DIGITAL. Businesses can ensure complete delivery and materials traceability and uncover smart insights for decision-making with connected logistics solutions. Drivers have the information they need at their fingertips, including their next ticket, so they can be back on the road to their next job as soon as their current delivery is made. To create more efficient fleet operations, companies are using tracking solutions to map the location of trucks in real time, as well as telematics devices to monitor truck performance parameters, such as engine speed and coolant temperature. These devices provide visibility into fleet operations, monitoring the unloading and loading of trucks and wasteful idling while in traffic or at the job site. Once management understands the cause of nonproductive hours in their operations, they can revamp processes for greater efficiencies, including using route planning and mapping solutions to avoid traffic delays.

Waiting on paperwork also hampers productivity. If processes are automated so that operations flow quickly and easily, workers don’t have to sit around and wait for paperwork to arrive.

The “Everyday Counts: Innovation Initiative” issued by the U.S. Department of Transportation in 2017 combined eConstruction with socalled Construction Partnering (aka E-C&P) in an effort to accelerate the adoption of electronic processes. E-C&P calls for training and aid for decision-makers and other key stakeholders, such as state DOTs, contractors, and consultants. Electronic material ticket management systems automate manual practices across the industry, eliminating tangible paper tickets and addressing the challenges created by outdated methods for tracking materials and truck assets.

Many successful pilots of eTicketing have occurred nationwide since the implementation of the “Everyday Counts” initiative, and the exchange of electronic ticket data has bridged the eConstruction gap that exists between public agencies and building materials suppliers.

DIGITAL COLLABORATION

Digitally collaborative technologies and tools that work on cloudbased desktops and mobile platforms provide clear insights into how materials and manpower are moving, placed and working.

The Infrastructure Bill poses an opportunity to not only upgrade the country’s infrastructure, but also to upgrade the tools and systems that we use to build our infrastructure. The old ways of working are no longer aligned with the new rules of success, and to close the gap between trading partners on projects, all industry players need to go digital.

With the $65B investment in broadband access, production facilities that are located in rural areas do not have to rely on on-premises software that runs locally at the facility without requiring internet connection to operate. This is an opportunity for all players in the industry to take advantage of the latest and greatest technologies in cloud and mobile computing, rather than relying on on-prem software that does not provide a single source of truth to all trading partners. With more broadband access, the industry can accelerate the adoption of cloud computing and mobile computing and eliminate the limitation of data exchange amongst trading partners on a job.

Command Alkon is in a perfect position to champion construction firms in completing the goals of the new legislation because we have aligned our products to equip each constituent in the infrastructure supply chain—DOTs, contractors, suppliers and haulers—with digital tools and an open, data-sharing network to promote end-to-end digitization and supply chain collaboration enabling real-time visibility to mitigate risk, identify issues before they become failures, and provide actionable and operational insights.

Data sharing and increased knowledge promotes better decision-making. With sufficient accurate data, construction companies can easily compare projected profitability and efficiency to performance. Contractors can use the collected data to increase bidding accuracy by finding and calculating hidden costs. Data analysis of historical performance records can improve asset utilization.

Drum mixers

www.tarmacinc.com

INCORPORATE CHANGE

The Infrastructure Investment and Jobs Act (IIJA) includes money for advanced digital construction management systems and related technologies. The program is funded at $20 million per year, for a total of $100 million, over five years. This funding is a clear indication of the critical role that technology will play in designing and building better, cost-effective infrastructure.

A boom in U.S. construction will play a major role in reviving a battered global economy, and it’s time to empower limited workers with solutions that help them to work more productively and avoid pitfalls and schedule delays to make the most of this investment.

Tarun Nimmagadda is the VP of Product Strategy at Command Alkon. Before being acquired by Command Alkon, Tarun served as the CEO and Co-Founder of Ruckit.

contact tarmac at 816-220-0700 or info@tarmacinc.com WWW.THEASPHALTPRO.COM | 59

NEW TECH

Sustainable Machines

BY SARAH REDOHL

T

o equal the greenhouse gas (GHG) emissions of a single Tier I 1990s-era piece of construction machinery would require 25 Tier IV 2021 machines, said Jeremy Harson, construction market director at Cummins, Columbus, Indiana.

Alongside experts from several other original equipment manufacturers (OEMs), Harson participated in a recent webinar presented by the Diesel Technology Forum on innovations to reduce construction equipment emissions.

“There are two ways to reduce emissions,” said Ray Gallant, vice president of sales support for Volvo Construction Equipment, Shippensburg, Pennsylvania. One, he said, is getting more production out of each gallon of fuel. The other is investing in cleaner fuels in the first place.

GET MORE PER GALLON

“We’ve looked at how the subsystems of the engine can be optimized and then how the engine is optimized inside the machine at a system level,” said Fred Rio, worldwide product manager of the construction digital and technology division at Caterpillar, Peoria, Illinois.

Alex Freitag, vice president of engineering at Bosch North America, Farmington Hills, Michigan, explained how Bosch has reduced emissions at the powertrain level through extended software functions, improved turbocharging, improved fuel injection, efficient temperature management and adapted exhaust-gas treatment, to name a few.

Harson said Cummins has also strived to reduce emissions while balancing this goal with customer value. He gave an example of Cummins’ B6.7 engine, which has reduced emissions dramatically from 1996 to 2019 while also increasing its peak power from 175 horsepower to 325 and improving fuel efficiency by 5 to 15 percent in that same time frame. Between the release of its Tier IV B6.7 engine and its Performance Series (2019) B6.7 engine, Cummins claims it has been able to achieve 9 percent more peak power and 30 to 40 percent more torque capability.

Zooming out to the entire machine, OEMs have invested in improved idle management.

Jon Gilbeck, manager of production systems, 60 | FEBRUARY 2022

During a 2018 research project by Volvo CE and its customer, Skanska, four 40-ton haulers were replaced with eight electric autonomous haulers running eight-minute dump/load cycles, with one minute per cycle to recharge at a quick charge station.

site development and underground at John Deere, Moline, Illinois, estimates idle time can range anywhere from 5 to 40 percent in some applications.

That’s why Deere has equipped its machines with auto idle, auto shut down and ultra low idle features, which not only reduce emissions and fuel consumption but also result in less maintenance for the contractor.

“If you’re not running, you’re not racking up hours, which is a way to extend that maintenance interval,” Harson said.

IDLE TIME CAN RANGE ANYWHERE FROM 5 TO 40 PERCENT IN SOME APPLICATIONS, ESTIMATES JOHN DEERE’S JON GILBECK.

The next step after optimizing each piece of equipment individually, Rio said, is to “take all the machines together on a job site and look at how we can optimize the way those machines interact with each other so we have a more efficient operation.”

For example, during a case study comparing Cat Connect technology and services to

traditional practices to pave a road, the Cat Connect job was able to reduce project hours by 46 percent, man hours by 31 percent, and equipment hours by 34 percent. This reduced fuel consumption by 37 percent.

“The greenest kilowatt is the one you don’t use,” Rio said. “If we can be more efficient, we can be greener and more profitable at the same time.”

CLEANER FUELS

Currently, Gallant said, combustion engines account for the vast majority of construction equipment in operation. As we move toward 2050, he anticipates that combustion engines will increasingly run on alternative fuels. He also expects battery electric equipment and fuel cell electric equipment to each grow to more than one-third market share.

“It’s really a matter of the duty cycle and power you need for each machine to get that particular job done,” Gallant said. For example, he added, battery electric drives will be well suited for compact machines, while heavier machines might be more suited for hybrid models with zero emissions fuel, and ultimately fuel cell and alternative fuels like hydrogen.

“Certain applications are more appropriate for electrification,” Freitag said, for example, daily usage below 250 miles. “If you

NEW TECH start going into construction equipment and long haul equipment where usage and load are increased, hydrogen fuel cell powertrains would be more favorable.”

However, electrification could be useful for the growing use of smaller construction equipment, like skid steers, compact track loaders and compact excavators. Gilbeck said these small machines have seen a compound annual growth rate of 10 percent for the past 10 years as job sites have become increasingly mechanized and labor continues to be a pressing issue.

Rio said he thinks electrification will either require automation or some level of process automation (like software) to determine when to charge which machines and for how long. “Today’s diesel tanks are designed to allow for full shift, whereas the technology for electrification at least in the beginning may not allow for a full shift, especially in heavier applications,” Rio said.

This could be seen in action during a 2018 research project by Volvo CE and its customer, Skanska, to electrify a quarry in

Sweden. They were able to reduce CO2 at the site by 98 percent, energy cost by 70 percent and operator cost by 40 percent by replacing four 40-ton haulers with eight electric autonomous haulers. The autonomous haulers ran eight-minute dump/load cycles, with one minute per cycle to recharge at a quick charge station. In the future, Gallant said, this would be an ideal use case for induction charging.

THE PATH FORWARD

“It took 100 years to build our petroleum infrastructure,” Harson said. “It’s going to take some time to move from diesel.” He anticipates another generation of advanced diesel equipment to be released at the end of this decade and a “rational, gradual phase-in” of equipment running on alternative power solutions.

“It’s going to take time for that infrastructure to develop and those technology costs to come down,” Harson said. “A lot of the equipment we’ve talked about today is what will be tasked to build that infrastructure.”

"Since making the switch to Meyer Laboratory’s asphalt release agents and drag slat cleaners at all the All States Materials Group plants throughout New England more than 2 plus years ago, we are extremely pleased with the performance of the products and customer service provided. I have also received positive feedback from our paving superintendent that Meyer’s products have performed much better than our previous products used on the tools, transfer machines, rubber tire rollers and pavers in the field.

Thank you again for everything - Todd Jarvis, Plant Operations Manager - Trew Stone, LLC a division of All States Material Group

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62 | FEBRUARY 2022

Furthermore, OEMs have to keep customers in mind. “They’re not necessarily getting paid more for buying an electric machine or using alternative fuel,” Gilbeck said.

That’s why each OEM discussed how, alongside emissions reductions, today’s equipment also offers reduced cost of ownership and improved performance.

As the infrastructure develops and costs for alternatively powered equipment come down, Harson said we can expect to continue to see reduced emissions from construction equipment year by year as a result of natural fleet turnover, given how much cleaner modern equipment runs compared to previous generations.

“On-road equipment typically has 10 to 15 years of machine life,” Gilbeck said, while off-road equipment is often in operation for up to three times as long as onroad machinery. “As we think about policy changes and the solutions we put in place today, we have to recognize that the solutions that are in the market today will be there for quite a long time.”

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Contact Us to determine which meets the requirements of your specific application Phone 952.939.6000 WWW.THEASPHALTPRO.COM | 63

We’re on it.

BROCK is proudly manufacturing equipment and supplying parts for hot mix asphalt plants.

BOOTH 1967

www.brock.llc | 2011 West Polymer Drive, Chattanooga, TN 37421 | 1.800.441.9528 | 1.423.476.9900

AD INDEX ALmix . . . . . . . . . . . . . . . . .7

Minds, Inc. . . . . . . . . . . . . . 41

Ammann America . . . . . . . . . 31

NCCP . . . . . . . . . . . . . . . . 63

Asphalt Drum Mixers, Inc . . 24, 25

Olson-Homestead Valve . . . . . 33

Astec Industries . . . . Inside Front Cover, Inside Back Cover, 11

Reliable Asphalt Products . . . . . . . . Back Cover

B&S Light . . . . . . . . . . . .34, 35

Sripath . . . . . . . . . . . . . . . 37

Blaw-Knox . . . . . . . . . . . . . .9

Stansteel . . . . . . . . . . . . 15, 43

BROCK . . . . . . . . . . . . . . . 64

Surface Tech . . . . . . . . . . . . 50

Clarence Richard Company . . . 63

Systems Equipment . . . . . .20, 61

CWMF . . . . . . . . . . . . . . 3, 49

Tarmac Inc. . . . . . . . . . . . . 59

Eagle Crusher . . . . . . . . . . . 17

Top Quality Paving . . . . . . . . 65

Fast Measure . . . . . . . . . . . 65

TransTech Systems . . . . . . . . 57

Gencor Industries, Inc . . . . . . . 4

Weiler . . . . . . . . . . . . . . . . 29

Greenpatch . . . . . . . . . . . . 45

Willow Designs . . . . . . . . . . . 65

Kenco . . . . . . . . . . . . . . . . 39

Wirtgen . . . . . . . . . . . . . . . 21

Meeker . . . . . . . . . . . . . . . 19

World of Asphalt . . . . . . . . . 51

Meyer Lab . . . . . . . . . . . . . 62

Wuori Consulting . . . . . . . . . 63

AsphaltPro’s advertiser index is designed for you to have quick access to the manufacturers that can get you the information you need to run your business efficiently. Please support the advertisers that support this magazine and tell them you saw them in AsphaltPro magazine.

WWW.THEASPHALTPRO.COM | 65

H E R E ’ S H OW I T WO R K S

Step 1 Step 3

The operator sets the material outputs, according to the configurable mix design.

AGGREGATE

The operator performs patching from the safety of the cab.

EMULSION

F

F

157 F o

E

0

LB/MIN

63 LB/MIN

Step 2

13.0 %

E

8.2

The operator uses the joystick and rotary control, following simple steps displayed on the in-cab touchscreen during operation.

LB/MIN

Step 5 Step 4 SPECS automatically increases or decreases the emulsion output, based on the operator controlling aggregate output, to maintain the mix ratio.

SPECS directs a final blast of air through the spray nozzles to prevent emulsion buildup, and the patch is complete.

Bergkamp’s SPECS

BY ASPHALTPRO STAFF

F

or contractors and agencies performing multiple pothole patches per day, the recently launched SP5E spray injection pothole patcher from Bergkamp Inc., Salina, Kansas, offers the ability to program the mix design and protocol for the day. Each SP5E comes with a spray-rate rotary control, joystick and touchscreen display, providing full operator command via Bergkamp’s exclusive “smart patching equipment control system” (SPECS). Here’s how it works: SPECS is designed to allow for easy change of application and spray rate for each repair, which provides consistency 66 | FEBRUARY 2022

across repairs each time, according to the manufacturer.

At the outset of the work shift, the operator sets the pre-determined mix design for emulsion and aggregate.

During patching, the spray-rate rotary control directly manages aggregate output and emulsion flow rate to maintain the mix ratio. The joystick controls the spray boom position, output start/stop, advance to next patch and toggle spray head oscillation. The in-cab touchscreen display provides easyto-follow steps and all other necessary information for the operator, including temperatures, rates, modes and diagnostics.

SPECS is designed to automatically ensure rates are maintained throughout the

day, which simplifies the operator’s process.

And because all operations are handled via in-cab controls, SPECS also improves operator safety.

For more information, visit www. bergkampinc.com.

SHOW US HOW IT WORKS

If you’re an original equipment manufacturer with a complex product, let us help you explain its inner workings to asphalt professionals. There’s no charge for this news department, but our editorial staff reserves the right to decide what equipment fits the parameters of a HHIW feature. Contact our editor at sandy@theasphaltpro.com.

BUILT TO CONNECT

Power and Portability Our portable plant configurations feature a variety of components including jaw crushers, cone crushers, impact crushers and a variety of screening plants. Without sacrificing power or productivity, portable options deliver efficient and reliable performance with extra portability and adaptability.

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