Go Green

Is it possible to get a high-quality product, recycle AND save money? ... Yes!

Asphalt Recycling

While Americans are accustomed to thinking about recycling their newspapers and beverage containers, the most widely recycled product in terms of both percentage and tonnage is actually asphalt pavement.

According to a report issued by the Federal Highway Administration and the United States Environmental Protection Agency, 80 percent of the asphalt pavement thats removed each year during widening and resurfacing projects is reused as part of new roads, roadbeds, shoulders and embankments.

According to the National Asphalt Pavement Association, approximately 73 million tons of reclaimed asphalt pavement (RAP) are reused, or nearly twice as much as the combined total of 40 million tons of recycled paper, glass, aluminum and plastics.

Relatively few people outside the pavement industry, however, know the extent of asphalt pavement recycling. In a survey commissioned by NAPA, Americans ranked asphalt pavement as being recycled the least among nine materials. (The others were aluminum, glass, paper, plastic, rubber, steel, wood and yard waste.)

For the asphalt pavement industry an 80 percent recycling rate is an everyday business practice.

"Using RAP results in lower costs. We use less virgin material and, by avoiding trips to the landfill, we use less diesel fuel. Considering today's fuel prices, these savings add up considerably for taxpayers on public road projects," commented Kevin Kennebeck of Performance Paving.

Other findings from NAPA help portray the state of recycling in America. For example, most Americans take part in at least some sort of recycling program. The survey showed that more than three-quarters (77 percent) said they recycle at least some aluminum cans. About two-thirds (67 percent) said they recycle newspapers, along with 65 percent who said they recycle plastic bottles; 60 percent, glass bottles; 58 percent, magazines; 55 percent, plastic bags, 54 percent, tin cans; and 53 percent who said they recycle white paper.

Reclaimed Asphalt Pavement

Reclaimed asphalt pavement (RAP) is the term given to removed and/or reprocessed pavement materials containing asphalt and aggregates.

These materials are generated when asphalt pavements are removed for reconstruction, resurfacing, or to obtain access to buried utilities. When properly crushed and screened, RAP consists of high-quality, well-graded aggregates coated by asphalt cement.

Asphalt pavement is generally removed either by milling or full-depth removal.

Milling entails removal of the pavement surface using a milling machine, which can remove up to 50 mm (2 in) thickness in a single pass.

Full-depth removal involves ripping and breaking the pavement using a rhino horn on a bulldozer and/or pneumatic pavement breakers.

Typically, the broken material is collected and taken to a central facility for processing. At this facility, the RAP is processed using a series of operations, including crushing, screening, conveying, and stacking.

Although the majority of old asphalt pavements are recycled at central processing plants, asphalt pavements may be pulverized in place and incorporated into granular or stabilized base courses using a self-propelled pulverizing machine.

Hot in-place and cold in-place recycling processes have evolved into continuous train operations that include partial depth removal of the pavement surface, mixing the reclaimed material with beneficiating additives (such as virgin aggregate, binder, and/or softening or rejuvenating agents to improve binder properties), and placing and compacting the resultant mix in a single pass.