||Asphalt Recycling Equipment
Asphalt, the sticky black substance that covers roofs and roads, is one of the country’s most recycled materials. There are many manufacturers in the market that offer the equipment needed for whatever process might be involved.
Joe Asher, business development director at Angelo Benedetti, Inc., said that Benedetti Recycling Equipment is unique in that it is the only asphalt recycling equipment that does not require any additional new material. Benedetti Asphalt Recycling Equipment recycles 100 percent of the existing asphalt roadway, with no need for an overlay. “Typically, the surface course is first heated via our asphalt pre-heater, to a temperature of approximately 350°. Next, the Benedetti Asphalt Recycler removes the asphalt to the desired depth (typically 2” or more) while funneling the material into a heated, on-board asphalt plant, where it is then mixed with a rejuvenating agent, and immediately placed in front of a paving screed for application. Last, it is compacted with a single hydrostatic roller to specified density. The roadway is complete in one continuous step, and may be driven on within minutes,” Asher stated.
Benedetti Asphalt Recycling Equipment has over 50 years of experience in the asphalt rehabilitation industry and they offer the only patented 100 percent asphalt recycling equipment available on the market today. Unlike all other companies in the industry, Benedetti Equipment consists of only 2 machines, each less than 80’ in combined total length, which processes up to 15’ in width. Asher said “most other contractors use equipment that spans over 300’ in length, which can only process 10’ in width. This severely limits application, allowing only for long stretches of rural highway.”
The company designed and built the very first Heater Planer, which was used in their early asphalt recycling projects. A shift from contracting to manufacturing occurred at Benedetti when so many wanted to buy their equipment and their products were featured on the Discovery Channel in 2011. Equipment production and lead times are always a challenge but each set of equipment is still hand-built to customer’s specifications. The Benedetti global market includes governmental agencies and contractors alike, seeking an environmental alternative to traditional asphalt paving methods.
BOMAG offers two distinct product lines for recycling asphalt on roadways according to John Hood, manager, Milling and Reclamation. The recycling process typically begins when BOMAG milling machines remove a defined amount of asphalt material off the top, usually due to surface failure. A new asphalt surface is then paved onto the existing base.
Hood explained, “In-place asphalt recyclers are often used when the entire roadway through the base structure has failed. Machines cut and pulverize old and deteriorated asphalt pavement and grind it together with the granular base material below. Often a binding agent is added to the material to improve its composition as road base material for the reconstruction of the road. BOMAG asphalt recyclers provide added flexibility and confidence due to a hydrostatic drive. The biggest concern when recycling asphalt is that unseen obstructions may be encountered when tearing up the roadway. The shock load from hitting a boulder, buried fencepost or other object can cause serious damage to a mechanically driven machine. With a hydrostatic drive rather than mechanical, BOMAG recyclers are designed to protect machine components when an obstruction is encountered by simply having the drum stall and hydraulic pressure directed to a relief valve.”
Hood went on to say that the hydrostatic drive also provides for more efficient operation by allowing operators to cut precisely on both sides of the recycler drum. “Municipalities or contractors can cut right next to a ditch or curb line with confidence to keep the job moving along quickly and accurately,” he said. The BOMAG MPH line of asphalt recyclers have been on the market for 40 years and BOMAG’s cold planer milling machines are the product of 40 years of expertise.
Hood noted that 40 years ago, municipalities and counties would often recycle and stabilize asphalt roadways with solidifying compounds. Due to the economic benefits, he said that trend is returning as a relatively inexpensive option for rebuilding or re-paving a roadway. He added, “This is also true in oil and energy production settings involving heavy truck and traffic loads on roadways that weren’t designed to withstand those uses.” Lastly, he mentioned that “Tier 4 emission regulations are an industry-wide issue for construction equipment manufacturers – asphalt recycling equipment and otherwise. The regulations are especially challenging for higher horsepower machines, requiring a lot of engineering and product development effort in recent years.”
Most of the11 million tons of asphalt shingles removed from homes annually is still put in landfills, where the material may take over 300 years to decompose. Recycling asphalt shingles can be cost-effective because they contain between 20 to 30 percent oil. Using recycled asphalt shingles (RAS) as a petroleum and aggregate substitute in the manufacturing of the hot mix asphalt used in road paving reduces demand for virgin asphalt by hot mix asphalt producers, while providing a buffer against oil prices and an opportunity to lower their operating costs. One normal-sized roof recycled into road mix makes about 200’ of a two-lane highway. And, due to its physical characteristics, the asphalt pavement produced from recycled shingles can be longer lasting than traditional asphalt pavement products. Roofing contractors that choose to recycle removed shingles, can promote their “green” building practices, as well as benefit from lower landfill disposal costs. In light of the economic and sustainable benefits, recycling asphalt shingles has been endorsed by the Department of Environmental Protection as well as the Federal Department of Transportation.
In order to incorporate recycled asphalt shingle material into hot mix asphalt, material must meet very demanding gradation specifications, so equipment grinding consistency is paramount. “That’s one of the real strengths of our horizontal grinders,” said Kevin Yuncker, industrial sales manager, Morbark Inc.
Yuncker said that his company offers the following shingle recycling models: the Morbark® 2600, 3800, 4600XL, 6600 and the 7600B Wood Hog. “Our Wood Hog horizontal grinders are capable of producing a 3/8” to 1/2” minus RAS product in a single pass. Other manufacturers have specific shingle grinding equipment or special ‘shingle grinding’ packages that must be built into the machines. Morbark’s horizontal grinders are engineered to give our customers the power and built-in features they need to maximize output and enhance their ability to not only process asphalt shingles into saleable products, but also brush, yard waste, clearing debris, storm debris, C&D waste and other mixed woody feedstocks without any modification to the machine except for screen size,” said Yuncker.
Jason Stepp, national sales manager for Stepp Manufacturing, stated, “At Stepp Manufacturing, we specialize in manufacturing asphalt equipment designed to heat, melt, transport and store bitumen and asphalt materials for highway maintenance, pothole repair and parking lot maintenance such as crack sealing, pothole patching and seal coating.”
Offering both recycling and reclaiming equipment, Stepp originated in 1942 and their primary focus has always been on the design and manufacturing of heating and melting equipment for the highway and roofing industries. Stepp also manufactures storage tanks and kettles for heating roofing materials. “Our innovations in efficiency, production and safety will continue as the industry changes. We utilize computer-aided design and manufacturing processes that allow us to rapidly incorporate new technologies and product improvements. Our production facilities and in-house engineering department allows us to build products to customer specifications and our network of dealers and after-sales service support assure that parts and service are available when and where needed,” Stepp said.
He defined the difference between asphalt recycling and reclaiming: “They are two very different processes. Asphalt recycling is taking broken chunks or asphalt millings from an older road surface and reheating and mixing the material to a hot usable state. With recycling you must add a small amount – usually one to two percent – of new asphalt binder to make the material workable and to replace oils that have dissipated or oxidized from the original material. Without this key ingredient you will end up with a dry patch material that just won’t bond.
“Reclaiming is reheating materials in a hot box and there is no mixing or adding a binder. One must be very careful on the material selection that is used. It is best to start with high quality mix which is mixed in a heated box, and a long period of time is needed for the material to accept the heat – usually three to eight hours, depending on the size of the load and the quality of material. Unlike using a mixer when recycling, the hot box must transmit the heat through the material. The biggest difference between these two processes is the cost involved. Recycling involves a more expensive machine due to the mixing and oil additive equipment. Hot boxes range in size and configurations and reclaiming is a more affordable option.”