|Mobile Asphalt Recycling Plants, such as this PT-Pro Series from Pavement technologies, allows paving contractors to process reclaimed asphalt pavement into durable hot mix, making the product available year-round for asphalt repairs even when hot mix producing plants are closed for the winter.
Without access to hot mix asphalt, most paving contractors and highway departments are left in the cold when it comes to pavement repairs. Needed repairs are put off until springtime or they’re forced to use cold-patch, an alternative to hot mix that does not last nearly as long and costs far more. For these reasons, more and more contractors are seeking year-round access to hot mix by utilizing mobile asphalt recycling plants, or MARPs.
Hot mix where and when you want it
MARPs reduce or eliminate dependence on fixed location hot mix producers without compromising the advantages of hot mix.
Set up at or near almost any job, MARPs are providing DOT, paving and utility contractors with a dedicated source of hot mix exactly where and when it’s needed 24/7, 365 days a year. Crews are filling potholes in the dead of winter, with hot mix, when hot mix plants are closed. MARP has proved to be remarkably beneficial on airfields where nighttime repair is the standard and daytime runway closure is unthinkable.
The best designed MARPs require only one person to load and operate, and every 20 minutes can deliver as much as five tons of hot mix ready for lay down. This new found freedom allows faster responsiveness and offers greater efficiencies in laying or repairing paved surfaces. With a cost of only $20/ton, recycling RAP is proving to be highly lucrative for pavers and offers equally important cost reductions for municipal owners.
First introduced in the 1970s following the oil embargo, reclaimed asphalt pavement (RAP) has become one of the most recycled materials in the U.S. Unlike cold-patch materials which often rely on petroleum cutback to soften the material for application, RAP can be reheated to reclaim its inherent strength and stability, yielding both excellent performance and significantly lower price compared with virgin asphalt and cold patch materials. This has made it a staple product for the paving industry – when it’s available.
|Without access to hot mix in cold weather months, pavers are forced to use far more expensive cold patch for asphalt repairs. Unfortunately, cold patch is also far less durable meaning many roads or highways will soon require new repairs after the cold patch work is done.
Municipalities, after all, are faced with the same problem as contractors when asphalt plants close down.
Sustainability – waste in, hot mix out
MARPs like PavementGroup’s PT-Pro Series Recyclers provide immediate, on-site access to hot mix wherever RAP is available. Batch recyclers allow asphalt millings and chunks to be processed simultaneously, mixing and heating the material – material torn up from streets, highways, runways, parking lots, driveways and other asphalt surfaces, go directly into the MARP for reheating. Small quantities of pelletized asphalt and/or rejuvenators can be added.
The resulting hot mix is ideal for paving repair work such as patches, potholes, utility trenches, foot-paths and base course. PavementGroup’ company president Mark Reeves notes, “With good stockpile management, RAP can be recycled into a good quality top course. Our customers making top course are generally screening and crushing their RAP and generally use our additive to improve workability and performance,” Reeves adds. “In 2009 we used the PT-PRO to recycle my driveway; whatever came up went back down. We documented the project so we could show off the results and I’d say the resulting job was a better binder than a top. She’s holding well although for a finer smooth finish I’d have needed to control the RAP by screening or crushing.”
Plant or recycler?
Some mobile recyclers also second as a portable asphalt plant, making virgin hot mix on a smaller scale. The U.S. Air Force, working with the National Center for Asphalt Technology (NCAT), developed and tested the system for airfield repairs. The USAF embraced the technology and is using NiTech Corporation’s system of prepackaged pelletized asphalt along with small skid-steer mounted mixers for high-mobility and PavemengGroup’s PT-PRO recycler for larger volume hot mix delivery. Reeves responds, “They (USAF) spent millions testing products and equipment. They even constructed a runway then…blew it up...for testing purposes. Our equipment worked well because the PT-PRO produces a homogenous mix of whatever goes in and its size and output capacity make for an ideal fit. The real secret was NiTech’s pelletized asphalt which exceeded the air force’s every expectation.”
“We generally load the machine with chunk asphalt that’s been torn up from previous pavings,” says McKinney.
“Depending on temperatures, we may have to add up to a gallon of SS1H per ton for better binding. The machine rejuvenates and reheats the asphalt until it comes out as a nice, new, beautiful material. You can’t tell its recycled, and I have zero materials cost.”
When you factor in the lower costs of transportation, the reduced burden of handling waste materials, and the savings in tipping fees at landfills, MARPs offer remarkable savings over the cost of hot mix from conventional, fixed-location plants. In fact, the right MARP can pay for itself in the first year or two.
“Depending on where you,” says Reeves, “you can pay anywhere from $55 to $125 per ton for virgin HMA and packaged cold patch runs $600/ton. Meanwhile, contractors could be stockpiling their RAP and recycling it for $20 per ton. That’s a huge savings. Recycle 50 tons on Monday and you’re talking about saving $1,500 bucks a day! We ask our customers, ‘Can you afford not to (recycle)?’”
McKinney said he is excited about the financial impact his MARP will have on his business.
“Over the past six months,” says McKinney, “this recycler has saved me nearly $100K and I’ve had it only about six months. This next year is going to be gangbusters for us. It’s an awesome machine.”
Robert Moskowitz has been a business writer since 1968.