Making the Most of C&D

Nov. 1, 2008

If your next grading and excavating project has you scratching your head for a way to cut costs and maybe even make some extra money to boot, it just might pay to take a closer look at your job site. The solution could lie right underneath you in the form of broken concrete, ripped up asphalt paving, or other demolition debris.

Mobile crushers, jaw and impact types alike, can process concrete, asphalt, brick, block, precast concrete, and natural stone into gradable aggregate for your project, eliminating the expense of buying and transporting aggregate to the job site. They can also enable you to recover rebar for sale to scrap dealers. In the process, onsite recycling can slash or even eliminate trucking costs and tipping fees to dump debris into landfills. What’s more, unlike trailer-mounted units, these track machines can move quickly and easily around the job site for more efficient crushing.

Mobile crushers also offer a cost-effective alternative to tighter controls on air and noise pollution and efforts to decrease traffic congestion in urban areas, notes Chad Montgomery, general manager of Western Retek Distributors Inc., which manufacturers a line of track-mounted crushers and screen plants. “Crushing demolition material onsite can help eliminate the negative environmental and economic impacts of hauling debris offsite,” he says. “Additionally, the material you process onsite can be put right back into the project as a base for roads or parking lots or as backfill and can even be sold and reintroduced into new concrete and asphalt which reduces the demand on the environment for virgin materials.”

The Economics Stimulus
Economics and regulations to divert recyclable waste away from landfills are helping to fuel increased sales of crushing equipment, reports Nikolaus Hottenroth, who oversees business development for the compact crusher manufacturer Rubble Master Systems Inc.

“In the past two years, the demand for our products has expanded from the more populated areas of the Northeast and California to all parts of the United States,” he says. “More and more contractors are recognizing the value of processing as much waste material onsite as possible.”

“Sales of our crushers have increased exponentially,” adds Eric Amberson, sales manager for Hartl Anlagenbau, GmbH., which makes jaw, impact, and cone crushers. “Contractors are using them to make such aggregates as a Type 2 spec product for highways and building pads and drainage rocks for pipe-backing material.”

His customers include highway builders, site developers, demolition contractors, and even trucking companies, which have gone into the crushing business as well as excavating and grading contractors. One of them is Jerry Bindner, who owns KBI/Action Crusher in Las Vegas, NV. The company provides grading, excavating, paving, and crushing services for commercial projects.

He bought his first crusher, a Hartl unit, in 2002 as a way to move out of the underground construction business. This past May, he replaced that machine with a new Hartl 1375 I model with an output capacity of up to 350 tons per hour. It’s used mostly for crushing native materials into Type 2 aggregate on company projects and for other customers.

“Ever since fuel prices shot up, the demand for custom crushing has really increased,” Bindner says. “Our customers are finding that it’s more cost effective for us to come in and crush the material to provide them a finished product than for them to bring in aggregate.”

More and more grading and excavating contractors who can’t justify a mobile crusher purchase are renting them for their smaller contracts, reports Montgomery.

“The rental market for this equipment is growing exponentially as contractors comply with local requirements to process material onsite,” he says. “Contractors are renting the machines for both the short and the long term, depending on the project size. And those who lease for the long term can often convert the lease to a purchase”

Profitable Recycling
“These days everyone in construction is trying to figure out ways to economize, to do more with less, and to create more value at every step of the business,” says Alan Huber, a Rubble Master dealer who owns Elms Equipment Rental Inc. in Brawley, CA. “If you can put the transportation and tipping dollars associated with conventional disposal of site debris back into your business, it doesn’t take that many tons of onsite recycling for compact crusher cost numbers to be attractive.” Hottenroth offers this look at how recycling concrete, asphalt, brick, and block construction materials onsite can improve profit prospects by reducing three key costs:

Landfill fees-They can range from several dollars per ton to more than $15 per ton, depending on location.

Transportation expenses-In addition to the price of fuel, maintenance, licenses, permits, and insurance, this expense reflects cycle times to and from your dumpsite. “A rural contractor may get as many as eight to 10 loads per truck per day,” Hottenroth says. “However, traffic congestion could limit a contractor in a major metro area to as few as four cycles a day, doubling this portion of the transportation costs in these two cases.”

“Usually, you can get about 25% more crushed material on a truck than when it’s unprocessed,” Huber adds. “So, even if you do have to transport the material offsite, you’ve reduced trucking costs by one-fourth.”

Aggregate costs-Depending on your area, the cost of aggregate materials for your project could range from around $5 a ton to more than $20 per ton. “These costs can have a significant impact on how you bid the job,” he says. “Onsite recycling will change your profit and competitive position in the market.”

Some Crusher Choices
A jaw crusher processes rock, concrete, asphalt, bricks, and blocks using both compression and normally using an overhead eccentric jaw to compress and rub the material between two steel wear plates. An impact crusher uses a spinning rotor with hammers to shatter material to a smaller size. It also contains a magnetic separator for removing rebar. Typically, impact crushers produce a finished product with a reduction ratio of between about 1:10 and about 1:50. For example, a crusher with a 1:20 reduction ratio can reduce 20-inch feed material to 1-inch base aggregate. Feed material bigger than this will result in a larger finished material size and reduced productivity of the crushing operation.

A jaw crusher, with its lower reduction ratio is normally used as a primary crusher to produce a 2.5-inch-minus product. It produces a much higher percentage of flat or elongated particles than an impact crusher. An impact crusher, on the other hand, produces a more consistent gradation of material that is cubical in shape. This shape provides the locking action required to achieve the higher percentage of compaction to meet specifications.

“In most cases, an impact crusher is the machine of choice because it offers more versatility,” Amberson adds. “Also, a jaw crusher can’t be used to recycle asphalt, because the heat generated by the crushing process will lock up the crusher.”

A cone crusher reduces concrete, brick, blocks, and natural stone by a rubbing action inside the crushing chamber. “It can’t process as large [sizes] of feed material as impact and jaw crushers, and it can’t handle steel or other metal scrap,” says Amberson. “Also, it can be used to recycle straight asphalt, because the heat generated by the rubbing process will lock up the crusher.”

When preparing concrete material for an impact crusher, it’s important to trim any rebar in a reasonable manner so that it doesn’t wind around the rotor inside the crusher housing, Hottenroth notes. “The size to which the material is prepped, the crushed material size, and production capacities of the crusher will affect the efficiency of the magnetic separator,” he says. “Even though the scrap price for rebar is lower than most, the money it generates can be significant over the course of a demolition project. In fact, some of our customers report that the rebar they sell to scrap dealers pays for the fuel to operate the crusher.”

More Selection Tips
Among other factors to consider in choosing a crusher that best fits your needs:

Size-The most efficient size of crusher is affected by your desired rate of production and size of finished material. The more secondary crushing required for achieving the final product, the higher the cost per ton.

“To determine the best size of crusher, start with the size of material you want to make and work back to the size of material you’ll be feeding the crusher,” suggest Amberson. “For example, if you want to produce the smaller aggregate, like three-quarter-minus, an impact crusher will be better, because a jaw crusher will leave you with a lot of oversize material that you can’t use.”

Wear rates-The wear life of a crusher depends on such factors as production rates, size of the feed material, and its moisture content, hardness, and abrasiveness. “The greater the percentage of fines, the higher the wear factor,” says Hottenroth. “Also, the wetter the material, the more abrasive it becomes. Asphalt is actually one of the most abrasive materials because the hardness of the sand and the lubricity of the asphalt makes for a very abrasive combination.”

The wear cost of Hartl impact crushers, for example, runs about 7 cents to 23 cents per ton, depending on type of material being crushed, Amberson reports. “The new ceramic-impregnated wear components greatly reduce operating wear costs,” he says. “If you’re working with high silica or other highly abrasive material, a jaw crusher will wear much more slowly than an impact crusher.”

Loading height-A crusher designed specifically for a track undercarriage has a relatively low chassis. This results in much lower feed height than a stationary machine, which has been adapted to accommodate tracks. The lower stance makes it a more versatile, more operator-friendly machine by eliminating the need to build a ramp for feeding the crusher, Amberson notes.

Transportability-The weight, width, and height of a crusher, of course, affect the cost of transporting a crusher to the job site. For example, the Rubble Master line of compact crushers, which range in weight from 13 to 31 tons, are road-legal for most lowboy tractor-trailer combinations, Hottenroth reports.

Load sensing-Crushers equipped with this feature can automatically slow the main feeder belt to prevent excessive buildup of material. That, in turn, can eliminate the time and hand labor needed to clear a material blockage inside the crusher.

Maintenance and repair-Bolt assembly and readily available components can reduce the time and expense of keeping a crusher up and running.

One Crusher Eliminates a Fleet of Trucks
Motivated by a desire to improve its bottom line while helping to reduce pressure on landfills, Peterson Excavating and Demolition of Gurnee, IL, bought its first crusher in May 2007. The 25-ton unit, a Rubble Master RM80 impact crusher, can process up to 150 tons per hour, depending on the materials. The company uses it to crush concrete, asphalt, and natural stone for its own projects and for customers.

By eliminating the need to haul out concrete or asphalt and bring in aggregate, using the crusher to process demolition rubble onsite has enabled the company to reduce the size of its truck fleet from 20 to three. Those remaining trucks are used for hauling dirt and some debris on smaller jobs that don’t justify use of the crusher.

“On jobs where we can recycle concrete or asphalt onsite and the general contractor wants the aggregate, we’ve completely eliminated the use of trucks,” says Willie Peterson, vice president of the family business, which includes his father, Brad, and mother, Linda. “It was no fun owning trucks. In addition to the fuel and license costs, we had the nightly expenses of changing tires, fixing broken windows, or other maintenance.”

Now, he reports, one operator can crush 50 loads of broken concrete a day, producing about 1,500 to 1,700 tons of 3-inches-minus in day. Plus, he no longer worries about how rising fuel prices will increase his transportation costs.

“Counting the time and distance to haul demolition debris to a recycling yard, the price of aggregate, and the expense of hauling it back, it was costing us $500 a load,” Peterson says. “Now we can make our own aggregate onsite for about $100 per load in fuel costs to operate the crusher. And, if we don’t want to use the crushed material onsite, we can usually sell it to another contractor down the street. The use of a recycled product also helps us to meet the requirements for environmentally sensitive construction projects and to get ahead of the others in the green game.”

The company also uses the crusher to salvage rebar, which at last report was selling for about $230 a ton.

Crushing each type of material, like natural stone, asphalt, or reinforced concrete, requires a different type of hammer, Peterson notes. “It takes two guys about 45 minutes to change the hammers,” he says. “We can go from crushing concrete in the morning to crushing asphalt in the afternoon.”

Peterson offers this advice to contractors considering adding a crushing operation. “Before you buy a machine, be sure you understand the crushing process, including how to adjust the crusher to make the desired aggregate size, and be prepared for the maintenance expenses,” he says. “That’s where a knowledgeable sales rep and a company that stands behind its products pays off.

“It takes a lot of work to get the process down right. But, for us, the cost and effort of getting into the crushing business has been worth it. Now we can stay busy throughout the year.”

Willie Peterson is available to answer questions about his crusher operation. Call him at 847-456-7667.

Some Mobile Crusher Choices
The Hartl line of track-mounted crushers includes four jaw-crusher models with production rates of about 200 to 500 tons per hour, more or less, depending on the model and type and size of feed material. All feature a “quattro” movement with an aggressive overhead concentric design, notes Eric Amberson with Hartl.

“Rather than relying on gravity for material to fall into the crushing chamber, the swing jaw continually pulls material into the chamber,” he says “As a result, it can handle 25% larger materials than a conventional jaw without blocking the crusher inlet. This quattro design works as both a primary and secondary crusher to produce a more cubical product and a higher rate of production than a standard jaw.”

Output of the six Hartl impact-crusher models also ranges from about 200 to 500 tons per hour, depending on the model and type and size of feed material. They can be used as primary or secondary crushers in recycling or natural stone applications to produce cubical end products.

More information is available at

The four models in the Rubble Master Compact Recycler line of impact crushers weigh from 13 to 31 tons and measure no more than 8 feet wide. “They are the most compact mobile crushers on the market,” says Nikolaus Hottenroth with Rubble Master Systems Inc. “Some models can be set up in a little as 10 minutes from the time you walk them off a lowboy trailer.”

The machines offer production capacities from 88 tons per hour for the RM60 model up to 220 tons per hour for the RM100, depending on material.

Unlike most impact crushers, which are hydraulically powered, the primary components of Rubble Master models are powered electrically, notes Hottenroth. “This diesel-electric configuration reduces fuel consumption by 30% to 50% compared with diesel-hydraulic crushers that provide the same output,” he says.

More information is available at

Size of the machine is another factor to consider when selecting mobile crushers. In the realm of mobile crushers, the smallest mobile jaw-crusher currently on the market measures no more than about 6.5 feet in length without its extraction belt in place and tips the scales at just about 7,400 pounds. “It’s designed for a small contractor taking on jobs like removing patios, sidewalks, and areas around swimming pools,” says Nick Baker, owner of Compact Concrete Crushers. This particular model, the LEM 48-25, is one of a line of mini-crushers made by Komplet Italia SRL that his company distributes throughout the US.

“You can transport this crusher from one job site to another behind a pickup truck,” he says. “You can use it backyards and other tight spaces to process up to about 15 tons of concrete an hour. You don’t have to screen the crushed material, and you don’t have to haul it away and bring in new aggregate. This compact machine separates the crushed concrete into medium and fine sizes that you can put back down to create a stable aggregate base for new concrete.”

Western Retek makes two sizes of track-mounted jaw and impact crushers. The 35-ton Predator series, powered by a Caterpillar Acert C11 engine, can process up to 385 tons of concrete or asphalt per hour, reports Montgomery. Production of the 50-ton Big Cat series, equipped with a Caterpillar Acert C13 engine, is rated up to 450 tons per hour. All come standard with remote operation for added operator safety.

Robust construction features include a heavy-duty undercarriage, main frame, and crusher module. Both types of crushers also have an independent vibrating grizzly. “It works as a pre-screener to improve separation of material before it moves into the crushing chamber,” Montgomery says. “You end up with fewer fines going through the crusher, reducing wear of components and increasing production efficiency.”

An efficient design of the impact crusher’s rotor chamber also adds to productivity. “The crusher features a higher rotor speed that allows you to process more material in less time,” Montgomery says.

Eliminating Spillage
A one-person, one-machine alternative to conventional screening systems that use a rough shaking or vibrating action to separate materials, the Flip Screen attachment features a smooth, 360-degree rotating action to screen dirt, rock, gravel, and other materials through a high-tensile mesh section of the bucket. Rotating the bucket in one direction screens the materials, with no spillage. Reversing the rotation ejects the larger particles.

Various models fit excavators, wheel loaders, telehandlers, backhoes and skid-steer loaders. Different screens, with mesh size ranging from three-quarter of an inch to 6-inches, can be changed in less than five minutes by one person without tools.

More information is available at

Turn Slash Into Cash
Demolition debris isn’t the only job-site waste material that can improve your profit picture. Trees and brush cleared from the job site also can be recycled into moneymaking products. Mobile horizontal and tub grinders, for example, can convert tree logs and limbs into valuable landscape mulch and fuel for boilers.

“You can bring a grinder onto you job site to grind up coarse wood and color it to produce a landscaping cover that typically sells at retail landscape centers for about $25 to $45 per cubic yard,” says Vince Hundt, national sales manager for Rotochopper, which manufacturers a line of mobile horizontal wood grinders. “The ground-up wood can also be sold to power companies, paper mills, cement kilns, and other large manufacturers as boiler fuel, or to wood pellet companies for making their products at prices that usually range from around $20 to $40 per ton.”

Contractor Report
Land-clearing contractor Triland Environmental of Peterborough, ON, bought its first grinder in 2002. “We wanted to add another revenue stream to our business,” says David Wood, who owns the company.

Currently, he has two Rotochopper mobile grinders: a 750-horsepower model 66, which can handle trees as large as 32-inches in diameter, and an MC-266, a 475-horsepower unit, which will grind trees up to 18-inches in diameter. “We recently added the MC-266 to help meet a growing demand,” Wood says. “It can work in smaller sites, and we can pull it behind our log truck.”

The loader-equipped log truck or an excavator is used to feed the grinders.

The machines are used to grind treetops and stumps into 2 inches or smaller for mulch, which a full-time salesman markets to landscape supply outlets. The units also make money by grinding wood from construction and demolition sites and pallets into boiler fuel. In fact, the company has an agreement with a fiberboard manufacturing plant to supply six to 25 loads a week.

“We use the big grinder to process yard- and woodwaste for a compost company. “Putting that material through a 6-inch screen takes a lot of horsepower, because it doesn’t shatter like wood does,” Wood says.

Essential Features
Among grinder features that are important to him are fuel efficiency and ease of maintenance. The manner in which the rotor operates affects fuel consumption, he notes. “Unlike a previous brand we owned, which cut the wood on the upswing, the machines we have now cut on the downswing, so that the rotor doesn’t pull up on the product,” Wood says. “Our largest grinder uses 18% less fuel than the higher horsepower machine it replaced to achieve the same amount of production.”

Quick access for maintenance and repairs is another money-saving factor to consider, he adds.

“Our current grinders have a larger door to get inside the machines to change screens or teeth or other needs,” Wood says. “Clearing out plugged material was a three- to four-hour process with our previous grinder. Now, it can finish the job in 30 minutes or less.

“No matter what brand you have, a grinder is a high-maintenance machine. That’s why my first and foremost consideration in buying a grinder is good service and support from the manufacturer. After all, you’re only making money when the machine is running.”

Has Wood been satisfied with the company’s decision to branch out into grinding?

“Yes,” he replies. “It’s hard work, and it’s hard on our employees, because they are away from home a lot doing custom work. But, in terms of net returns, it’s worked out well for us.”

A Look at Some Grinder Choices
The Rotochopper line of wood grinders includes three mobile diesel models for use in producing mulch and hog fuel on land-clearing sites. They include the 350-horsepower MC-256, the 475-horsepower MC-266, and the 750-horsepower B-66, with weights ranging from about 36,000 to 63,000 pounds. Features include color systems for mulch and an easy-in, easy-out side entry for changing screens. They can also be used to process bark, to grind pallets, slab wood, and industrial woodwaste, and to make compost.

The B-66 includes the only metal alert and diagnostic system on the market that stops the grinder before it takes in steel items, says Hundt with Rotochopper.

The two smaller models do not require any permits to travel, while the B-66 is slightly over-width and requires a permit. All three set up and are ready to run in less than 15 minutes,
Hundt adds.

More information is available at ww­

Multi-Purpose Attachments Remove Stumps and More
Continental Biomass Industries Inc. offers three attachments for removing, preparing, and loading stumps for grinding.

Two ripper teeth on the CBI Stump Shear pull the stump of the ground while a steel plate backfills the stump hole. Dual action cylinders and a knife shears and splits the stump. Shearing the stumps reduces wear and tear on the grinder by removing most of the dirt and rock, the company reports. Designed for 50,000- to 100,000-pound-class excavators, the company rates production of this attachment at 50 tons and more of stumps and butt logs per hour.

Built for 65,000- to 85,000-pound-class excavators, the CBI Detachable Stump Ripper and Shear II uproots stumps, backfills stump holes, shears stumps, splits stumps and butt logs, and loads them along with brush into a grinder. It is also available with a quick-detach coupler.

The KH-160 Stump harvester, for use with 35,000- to 65,000-pound-class excavators, can be used for tearing, cutting, and breaking a variety of wooden materials, the company notes. It will dislodge smaller- and medium-size stumps and pick them up in one piece. It will split large stumps before dislodging them and then picking up the pieces.

More information is available at