Saves money and the environment
By Jeff Winke
Hands down, recycled or reclaimed asphalt pavement (RAP) is America’s most recycled material.
A report from the Federal Highway Administration shows that 80 percent of the asphalt pavement that’s removed each year during widening and resurfacing projects is reused. That percent is substantially higher than the Environmental Protection Agency’s comparison recycling rates of 60 percent for aluminum cans, 56 percent for newsprint, 37 percent for plastic soft drink bottles, 31 percent for glass beverage bottles and 23 percent for magazines. Interestingly, in a survey of 1,009 adults commissioned by the National Asphalt Pavement Association (NAPA), Americans ranked asphalt pavement as the material they thought was recycled the least among nine commonly recycled products.
One can say that RAP was “green,” before the term living green meant making lifestyle decisions and engaging in practices which reduce negative impact on and promote the health of the planet and its creatures. Recycled asphalt pavement is not only ecologically sound, but it is an effective choice for the reconstruction, repair, or replacement of worn asphalt pavement.
In order to demonstrate the effectiveness of reclaimed asphalt, the National Asphalt Paving Association (NAPA) partnered with the FHA with the goal of quantifying the impact of RAP. They wrote: “According to the latest survey data, during the 2016 construction season more than 76.9 million tons of RAP and nearly 1.4 million tons of recycled asphalt shingles (RAS) were put to use in new pavements in the United States, saving taxpayers more than $2.1 billion. Also, more than 30 percent of all asphalt pavement mixture produced in the country that year was made using warm-mix asphalt (WMA) technologies.”
Milling and full-depth removal remain the two main ways reclaimed asphalt is made.
When talking about asphalt recycling, there are a few different methods that are considered “asphalt recycling.”
Michael Blake, director of marketing for KM International, North Branch, Mich. described several methods:
- Asphalt recycling by means of a mobile asphalt recycler. Millings and asphalt chunks are loaded into a machine, then mixed, tumbled, dried out, new asphalt cement is added and the end result is recycler asphalt.
- Infrared recycling which occurs as an in-place designated repair area using an infrared asphalt recycler to scarify, lute, and compact.
- Hot In-Place Recycling is achieved by a large machine scarifying an entire road lane and then another machine rejuvenating and then compacting the material back into place.
- Asphalt Plants have also started to use Recycled Asphalt Product (RAP) as part of their production process.
As an option, Soft Heat Mfg., based in Plains City, Ohio, offers a portable asphalt reclaiming unit that heats the existing asphalt already in place and allows the contractor to rework it and add more asphalt if there is a void to fill.
“We refer to the reclaiming of asphalt as returning it to a usable and workable state,” said Dave Price, president and developer with Soft Heat Mfg. “The idea is that every contractor can use bunked up asphalt product instead of hauling leftover new product to a dump. The reality is that cold and unused new product is readily available as leftovers all the time and can be reclaimed at 200 pounds at a time, in less than seven minutes. One can reclaim old asphalt as well, if it’s in chunks that are shoe-box size or smaller.”
Price continued: “When you consider that left over asphalt mix gets dumped every day, and at a cost to do so, that with proper equipment, it can be reclaimed at great profit. There is no need for rejuvenators, no mixing required, and the weather season or temperature does not matter. This is an ideal product for patchwork and repairs as well as to fill and level damaged surfaces. If you think about it, this is recycling at the front line and at its best!”
There are various types of equipment that can be used to recycle asphalt.
“There are asphalt hot boxes and recyclers that can be equipped to reclaim virgin uncompressed asphalt or recycle RAP or asphalt millings,” stated Ric Simon, executive vice president, Falcon Asphalt Repair Equipment, Freeland, Mich. “For example, our trailer-mounted, slip-ins and hook-lifts can be equipped with dual burners to enhance the reclaiming and recycling of asphalt in an overnight process. Once recycling is completed in the machine, it can be transported to the repair location in the same vessel it was recycled in. You load the materials into the Falcon Hot Box & Recycler, heat it overnight, transport the machine with hot recycled asphalt to the repair areas and fill the potholes.”
Simon added: “From a ‘green initiative’ and care for the environment standpoint, the ability to use RAP versus new hot mix is certainly a benefit.”
Recycling requires less energy than producing new.
Most roads are made from concrete or asphalt. Mining the raw materials for either product requires massive amounts of energy and disrupts the environment from which they are extracted.
Producing cement, an essential component of concrete, releases high levels of volatile organic compounds (VOC) into the atmosphere. VOC emissions are harmful to the environment and contribute to ozone depletion. Asphalt is a petroleum-based paving material. Drilling for oil also requires a significant amount of energy and the environmental hazards associated with extracting oil have been well documented.
Environmental impact does not end at the manufacturing stage. Paving new roads and parking lots disrupts the underlying soil and water table. Soil beneath the paved surface that would otherwise guide rainwater into underground streams and eventually into rivers and waterways immediately dries up. Rainwater instead is channeled into engineered drainage systems that direct the water into municipal sewage systems before dumping it into rivers and lakes.
Further, striping paints and sealers for roads and parking lots often use petroleum in their formulation and/or feature high-VOC emissions. Although producing materials and placing new pavement is wrought with environmental consequences, the use of reclaimed asphalt you can mitigate the impact.
There are other benefits of using recycled pavement versus new virgin asphalt.
“To me, there are three distinct benefits to using recycled asphalt pavement–cost, availability, and new opportunity,” stated Greg Harla, part owner of Pavement Recyclers/Bagela USA, Shelton, Conn. “The cost with large volumes of recycled blacktop can cost as little as $19 per ton, all in. With regard to availability, RAP can be produced any time, anywhere. In many parts of the country, asphalt production plants close for the off-season, so many, many of our customers can continue to work, installing infrastructure, patching/repairing, etc. And with respect to new opportunity, quite a few of our customers sell material during the off-season using their Bagela recycler.”
In terms of durability, RAP matches new asphalt.
“In pothole repair operations, RAP is generally considered to be a very acceptable product from a durability standpoint,” Simon said. “In most operations that we see, recycled asphalt product can be used to produce very high-quality, long-lasting pothole repairs.”
Reclaimed asphalt definitely has its role.
“Like any asphalt application, the durability and longevity will depend on the application method and preparation,” Blake stated. “If the recycled asphalt was produced properly–meaning it encompasses 3-5% asphalt cement and all other factors are equal–RAP could last just as long as virgin hot mix asphalt.”
Harla said: “Several of our customers, that strictly pave, will use recycled mix for the base and top with graded plant mix. By doing so, the recycled mix provides a strong base and the thinner top, is icing on the cake!”
Recycled asphalt pavement is a useful alternative to virgin materials because it reduces the need to use virgin aggregate, which is a scarce commodity in some areas of the United States. It also reduces the amount of costly new asphalt binder required in the production of asphalt paving mixtures.
Jeff Winke is a business and construction writer based in Milwaukee, Wisconsin. He can be reached through firstname.lastname@example.org