As exhausting as the nonstop coverage of COVID-19 can be, how the C&D recycling sector bounces back from the drastically diminished incoming volumes many markets saw in Q2 is wholly dependent on how the virus affects construction and demolition activity in Q3 and beyond.
In an Associated Builders & Contractors (ABC) report released July 2, ABC Chief Economist Anirban Basu noted that the construction industry added 591,000 jobs between May and June. This recovery represented a rehiring of 56 percent of the jobs lost since the pandemic started.
Although Basu points to such indicators as positives, he notes that there is still a high degree of uncertainty in making prognostications about the coming months.
“Since the pandemic devastated the economy, most economists have been predicting a V-shaped recovery,” Basu says. “To date, this has proven correct. While recovery is likely to become more erratic during the months ahead due to a number of factors (including the reemergence of rapid COVID-19 spread), recent employment, unemployment, residential building permits and retail sales data all highlight the potential of the U.S. economy to experience a rapid rebound in economic activity as 2021 approaches.”
“However, even if the broader U.S. economy continues to rebound in 2020, construction is less likely to experience a smooth recovery,” Basu continued. “The recession, while brief, wreaked havoc on the economic fundamentals of a number of key segments of the construction market, including office, retail and hotel construction. Moreover, state and local government finances have become increasingly fragile, putting both operational and capital spending at risk.”
The rebound in the construction sector signaled by the rehiring of over half the jobs lost since early March is similarly reflected in volumes coming into C&D recycling facilities. On the Construction & Demolition Recycling Association’s (CDRA’s) May 29 conference call with recyclers throughout the U.S., many participants acknowledged that tonnages were down between 50 and 80 percent from the previous year. However, on the association’s June 26 call, recyclers reported that incoming tonnages of mixed C&D improved notably, despite still being down approximately 25 to 35 percent from the prior year.
So, what type of activity might we expect for the rest of 2020?
In a recent survey of over 630 construction firms conducted by the Associated General Contractors of America (AGC), 42 percent of respondents said they did not expect demand to recover to normal levels for at least four months, with most firms expecting a recovery to take longer than six months.
With COVID concerns appearing to present major challenges in the commercial sector for the foreseeable future, infrastructure legislation could be the shot in the arm needed to jump-start building initiatives throughout the country. As the 2020 election nears, it will bear watching if Democrats and Republicans can come together for bipartisan legislation that can get Americans back to work and C&D recycling volumes back to something at least close to normal.
Scrap Iron: Reported United States aggregated spot market prices per gross ton shown for each commodity are based on all Management Science Associates’ (MSA) Raw Material Data Aggregation Service (RMDAS) participants’ actual order data submitted to and processed by MSA as of the 20th of each respective “buy month,” rounded to the whole integer. A map of RMDAS regions is available at http://rmdas.msa.com, as is a further explanation of RMDAS methodology and an accompanying disclaimer.
No. 1 HMS defined as prepared obsolete scrap, 5 feet long and under. Additional pricing information on each grade can be found at www.RecyclingToday.com.
Copper - LME Pricing: Source: London Metal Exchange, www.lme.com
Aluminum - LME Pricing: Source: London Metal Exchange, www.lme.com
Stone and Aggregate Pricing: *Index is based on 1982 average price as 100 Source: U.S. Bureau of Labor Statistics
Wood Scrap: Source: Forisk Wood Fiber Review; detailed pricing and market analysis for regions in the U.S. and Canada available by subscription at www.forisk.com.
MBL Recycling sees many benefits from its electric Builtrite material handler
Custom Content - Sponsored Content
The key advantage of a stationary electric machine is that the electric power unit can be separated from the machine and moved from a dusty environment.
In the residential Chicagoland suburb of Palatine, Illinois, a business has grown substantially in recent years but has managed to keep its high-volume recycling operation largely out of sight. The street out front is clean and quiet, yet inside the walls of MBL Recycling’s facility lies a state-of-the-art construction and demolition (C&D) recycling center.
In 2005, MBL owner Rob Lenzini and his family saw a need for a recycling facility that would serve the northern suburbs of Chicago. As in almost all areas of the country, especially urban areas, landfills were being closed or facing dumping restrictions.
The main problem with recycling C&D debris is coming up with an economical and safe means to separate the materials so they can be sent to other facilities for processing as secondary products or for use as raw materials to make plastics and metals. However, over the last 20 years, significant progress has been made to develop sophisticated systems to sort like materials into their respective categories. Most facilities still use some manual labor for sorting, though robotic solutions are on the horizon to take over at least some of these tasks. MBL is no exception and has invested heavily to create a state-of-the-art operation.
Traditionally, diesel-powered hydraulic excavators equipped with either a bucket or thumb combination or a grapple attachment have been used to help sort, compact and load this material into feed hoppers. But operators in these challenging and dusty enclosed environments find that diesel machines tend to overheat because of frequent clogging of their air filters. These machines also require an added level of maintenance to ensure their performance. Typically, these excavators have their engine lives shortened significantly in this environment. Beyond maintenance considerations, running diesel engines in an enclosed facility poses its own set of health risks because of the exhaust fumes.
Builtrite Manufacturing saw an opportunity to provide a real solution to the industry. Builtrite has been designing and building stationary electric material handlers since the company’s founder saw a need for these machines while working in transfer stations in the 1980s.
As the world started seeking “greener” solutions that help reduce fossil fuel emissions, other industries have sought out Builtrite equipment for handling C&D debris, scrap metal and logs. The handlers have come to be used in these and other high-volume production processes.
The key advantage of a stationary electric machine versus a diesel unit is that the electric power unit can be separated from the machine and removed from the dusty environment. Because electric motors do not require air for combustion as diesel motors do, there are no air filters to replace. Also, because no harmful emissions are produced, they can be used safely indoors. Finally, because electric material handlers are bolted to the floor, no tires or tracks need to be replaced, and those expensive reinforced concrete floors last much longer. Overall, running an electric material handler—as opposed to a diesel machine—typically cuts operational costs in half and reduces maintenance costs even more.
Lenzini, recognizing the advantages of the stationary electric handler, decided to contact Builtrite about procuring one for MBL’s facility. After touring MBL’s MRF and evaluating what Lenzini needed to accomplish, the Builtrite team went to work.
The Builtrite team and Lenzini concluded that Builtrite’s model 2300-SE had the proper amount of reach and lift capacity and was the right tool for the job. However, Lenzini wanted some specialized components, including a custom boom and the ability to use a fixed-style demolition grapple. To fulfill Lenzini’s needs, the Builtrite team collected information from MBL and then made a drawing proposal, customized for the specific facility needs. After feedback from the MBL team, Builtrite made several changes, and the green light was given to produce the machine.
“What I liked best about dealing with Builtrite was their willingness to listen to my specific application needs and suggestions on what it would take to produce a machine that would work well at my facility,” Lenzini says. “We decided to have the power unit moved off the machine and placed on the other side of our sorting hopper, keeping it away from most of the dust. We also incorporated an autolube system to reduce wear, maintenance and downtime and installed stairway access to the cab. I also wanted a machine made in the U.S. Builtrite was the solution that checked all the boxes.”
While MBL Recycling was recently purchased by Economy Disposal, the site’s Builtrite material handler promises to be a fixture of Economy’s recycling operations for years to come.
When asked about the acquisition and Builtrite’s contribution to the MBL facility, Economy Disposal President Ron Tazelaar said, “Rob is still with us, and we’re really pleased he chose to purchase the Builtrite 2300 SE! It’s right here with us as we grow this business.”
Dick Reeves General Kinematics Director - Resource Recovery
1. Why choose GK as your integrator?
We developed GK Systems to enable us to be the one-stop, one call, one company to support all your recycling needs. In blending our history with our engineering expertise, we are able to incorporate cutting-edge technology into recycling systems. GK provides world-class support directly to the customer, removing any potential headaches and confusion caused by less responsive integrators. Having direct control of the project allows us to steer clear of common system integration pitfalls—ultimately, allowing us to provide the ROI our customers deserve. For decades, we have worked with many talented partners. Our 60 years in the industry have allowed us to create partnerships with the best equipment providers in the industry. At the end of the day, we believe we’ll provide a better overall system experience for our customers.
2. Why did GK make the decision to focus on system integration?
GK is well-known as a custom equipment manufacturer for a variety of material handling applications. In the past, we have worked with customers to develop unique solutions, provide engineering support and incorporate technology to enhance recycling processes. So, it made sense for GK to officially announce that we are doing system integrations. We’ve seen a gap in the markets we serve for companies to provide this level of support. We believe in the equipment we have in operation and know that we can provide a higher level of service to the recycling industry.
3. What differentiates GK from other system integrators?
Our customers rely on us to provide a high return on their investment. This continues to be our focus when integrating systems. System integrators rely on OEMs to provide the necessary equipment knowledge. We have extensive equipment knowledge and expertise in all areas of recycling across multiple applications. At our core, we are an engineering-based company; we understand the principles that make a great system. Bundling our core equipment knowledge with our engineering expertise into one service offering creates a winning combination for our customers.
4. How will GK apply its expertise to better serve the industry?
We have a team dedicated to the C&D industry. Their expertise covers everything from the design and build of equipment through plant operations. It’s because of this commitment to the industry that GK becoming a full-time system integrator makes sense. We are known across the globe for our innovative recycling equipment for sorting systems. Due to products like the Finger Screen 2.0 and the De-Stoner, we have become a leader in vibratory screening and classification technology. GK’s jam-resistant, dependable and high-capacity sorting solutions increase the profitability of recoverable commodities. Our recycling equipment is engineered to require less maintenance while maintaining a longer service life. The systems we create are designed so that each component seamlessly integrates to create a proven process that will maximize operator profits.
5. How does GK provide ongoing support for its customers?
The ongoing support of this equipment is something we take seriously, which is why we offer global support 24/7. GK is known for world-class support, and our dedicated project management team will ensure projects remain on time and on budget. We take great pride in the quality of our equipment and will continue working with the customer to keep our machines running at peak efficiency for the life of the system.
A solid mix
Features - Shingle Processing
NAPA’s guidance regarding RAS concentrations in new hot mix asphalt formulations may help the use of recycled materials gain more acceptance from paving contractors.
The use of recycled asphalt shingles (RAS) in asphalt pavement has become increasingly popular among paving contractors seeking a cost-efficient alternative to virgin materials. Consisting of asphalt cement, aggregate and fiber, the composition of RAS can make it an ideal substitute for the virgin asphalt and fine aggregate routinely used in hot mix asphalt (HMA) formulations.
According to the National Asphalt Pavement Association (NAPA), asphalt mixture producers used more than 1 million tons of RAS in asphalt pavement mixtures during the 2018 construction season, and in the process, diverted about 10 percent of the total available supply of waste shingles from landfills.
While this was a 12.5 percent increase from the 980,000 tons used in 2017, it is only a fraction of the approximately 11 million tons of asphalt shingles disposed of each year.
In an effort to further the sustainable practice of utilizing RAS in asphalt mixtures, NAPA released an updated report in 2019 on the use of reclaimed shingles in asphalt pavements. The report, which was an updated version of the association’s “Guidelines for the Use of Reclaimed Asphalt Shingles in Asphalt Pavements,” laid out a number of best practices associated with RAS usage.
“I think the big thing that we just have to encourage is if you’re going to use this material, then you’ve got to do your homework,” Richard Willis, vice president for engineering, research and technology at NAPA, says. Willis was also a co-author of the report. “You have to know your material properties, such as your typical aggregate and binder, as they become even more important [when using RAS in mixtures].”
COMPOSITION
Although the composition of asphalt roofing shingles can vary depending on the manufacturer, shingle age, product line and roofing application, most contain a basic mix of asphalt binder, filler, fine aggregate or granules, and fiberglass or organic felt.
“[Practically] every asphalt mixture that we make has two of those same ingredients in it. You’ve got the asphalt binder and you’ve got some kind of fine aggregate that’s involved in the fines system,” Willis says. “When you’re looking at using the shingles in an asphalt mixture, we use them in very small dosages because your typical shingle is going to be somewhere between 20-30 percent asphalt binder depending on how old it is and what type of fiber was used with it.”
The aggregate or mineral granules on the surface of the shingles are often very durable and angular, which can be desirable for incorporation in asphalt mixtures. In addition, the surface aggregate in shingles can create added voids in mineral aggregate (VMA) in the asphalt mixture.
According to NAPA, achieving proper VMA in asphalt mixtures is a key part of meeting the volumetric properties needed to ensure a strong aggregate skeleton, the ideal amount of asphalt binder and proper air void space to provide optimal performance against cracking, permanent deformation and aging.
“When using shingles, it all comes down to ensuring these mixtures are engineered well,” says Willis.
All other photos provided by ASR Systems
SOURCES
Waste shingles used for the production of RAS are usually sourced from two major categories—post-consumer asphalt shingles (PCAS) and manufacturing waste asphalt shingles (MWAS).
MWAS, which is typically generated from manufacturers scrap, is often preferred by processors because it is free of many contaminants such as nails, wood and asbestos that might compromise PCAS composition. However, with sources of MWAS limited by geographic availability, many producers are left with only PCAS as an option.
According to NAPA, processors of RAS end up using PCAS volumes 10 times greater than that of MWAS thanks to its availability, which is usually derived from reroofing activities.
While NAPA recommends shingle recycling operations consider local, state and federal requirements when addressing contamination, the association has identified two basic modes for acceptance of PCAS.
Source separating requires the roofing contractor to deliver only clean PCAS to the recycling facility. According to the report, the shingles should be free of wood, plastics, large scrap metal, dirt, rocks, adhesives, solvents, petroleum contamination, other trash, and other substances deleterious to the shingle recycling processes.
“Most of the specifications when you look at them do have a requirement for what we would call ‘deleterious materials,’ and that’s basically our way of assessing contamination,” says Willis. “We have pretty tight specifications and requirements that states set out to ensure that these materials are clean, but it is a continual process as we figure out how to make them cleaner.”
Mixed roofing waste loads, on the other hand, require sorting the PCAS from the waste at the recycling facility. These can vary from simple “dump and pick” operations to more elaborate systems with screens, conveyor systems, and elevated picking stations to remove non-shingle materials.
PROCESSING
To produce RAS, sorted shingles are fed into a grinder or shredder to be processed. The ground or shredded shingles then pass through a screening process where material of a specified size is stockpiled for use in asphalt pavement mixtures.
NAPA states there can be some variance with what grinders or shredders may be used to process shingles, with each manufacturer utilizing a unique combination of material-handling and size-reduction designs.
In general, the grinder will include a loading hopper, a feeding drum to move the shingles into the grinding chamber, a grinding chamber with cutting teeth, a sizing screen and an exit conveyor.
To combat the excessive heat generated during the shredding or grinding of shingles, Willis recommends adding water to the shingle material as it is fed into the grinding chamber.
“Because you’ve got very stiff material that you are grinding at very rapid speeds, one of the challenges that you see is you have a lot of heat that’s developed,” he says. “With asphalt binder, as it’s exposed to heat, it gets softer. So, to really prevent it from gumming up the system, they use the water to process and keep it cooler to help the system stay active and running smoothly.”
MIXTURE
RAS contains stiffer asphalt binder, fibers and filler, as well as hard, durable and angular aggregates. With this is mind, several studies have illustrated the importance of accounting for recycled binder properties when incorporating RAS into an asphalt mixture design.
According to the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications and Standard Practices for using RAS in asphalt mixtures, there are three areas to address when utilizing recycled shingles: shingle aggregate gradation and specific gravity, binder quantity requirements for effective asphalt, and binder quality requirements for binder embrittlement.
Of these guidelines, some research has found that increasing the VMA requirements will increase the total and effective asphalt binder in the asphalt mixture. This is because the asphalt binder in RAS does not fully liquefy during asphalt production, leaving a portion of RAS asphalt binder that does not become effective during production.
In addition, the AASHTO MP 23-15 specification requires RAS be processed so that 100 percent passes the 3/8-inch sieve to optimize blending. Variations in processed RAS gradations have resulted in a range of RAS asphalt binder effectiveness when mixing with new asphalt binders. Generally, finer RAS gradations lead to higher effective asphalt contents.
“States and areas are starting to look at not just developing a recipe for these mixtures, but also starting to incorporate some tests that will allow people to have higher confidence that these mixtures are going to perform,” Willis says. “That may allow people to open up their specifications of their standards a little bit.”
The author is the assistant editor for Construction & Demolition Recycling magazine and can be reached at hrischar@gie.net.
Adam Redling
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