During the past 27 years the Asphalt Recycling & Reclaiming Association (ARRA) has been active in researching ways to improve the techniques, equipment and additive technology that work within its recycling construction practices. The association is a group of contractors, suppliers, affiliate members and government agencies that have come together for the common cause of making recycling a first consideration in the rehabilitation of any asphalt pavement, whether it is a highway, runway or parking area.
"First Consideration" is what the Federal Highway Administration feels should be the practice when any of its 160,000 miles of pavement and its 128,000 structures are being considered for replacement. These monuments to the world's largest and safest highway system where built using large quantities of asphalt, concrete, steel and aggregate. Much of the system was built in the 1960s and '70s and is in need of major rehabilitation or total reconstruction, and much of the materials used to build that system can be recycled for use in new construction. In February 2002 the FHWA put forth its "Recycled Materials Policy," which stated:
* Recycling and reuse can offer engineering, economic and environmental benefits;
* Recycled materials should get first consideration in material selection;
* Determination of the use of recycled materials should include an initial review of engineering and environmental suitability;
* An assessment of economic benefits should follow in the selection process; and
* Restrictions that prohibit the use of recycled materials without technical basis should be removed from specifications.
In order to carry out the mission of the FHWA to "improve the quality of the National Highway System," the NHS must be properly preserved, maintained, rehabilitated and when necessary reconstructed. Maintenance of highways and associated structures is critical to our ability to provide the safest, most efficient roadway system possible, while simultaneously providing the greatest level of protection to the human and natural environment.
The population of our country is increasing at an alarming rate. There are significant changes in our population, work trends, what we eat and what we do for entertainment. All of this affects our highways. Commercial transportation now brings us water from France, coffee from Colombia, cereal from Nebraska and fruit from Asia. All of this is transported on our failing infrastructure.
Since the end of World War II the baby boom has been working its way toward retirement. By 2010 the number of persons in their 60s will increase by 50%. Our aging and retired population will not stay at home; they will be out and about traveling our highways. The number of car-less households has declined from 21% in 1960 to 10% today.
Immigration that accounts for more than 35% of our population increase, shifting age groups, foreign visitors to our shores and the increase of women in the workplace--all of these along with the natural elements cause premature deterioration of our asphalt and concrete highways.
State, county and local government agencies are going through the same problems. How do we cost-effectively remove and discard the old, cracked or broken asphalt pavements that are no longer serviceable and replace them with all new material? What do we do with this infrastructure that needs constant rehabilitation? The answer to that is we need to preserve and reuse more of this huge natural asset that is already in place.
ARRA has six different disciplines that can effectively recycle and rejuvenate those deteriorated asphalt pavements. Dry planning, hot plant, hot in-place recycling, cold in-place recycling, full-depth reclaiming and soil stabilization will address any depth of problem associated with asphalt pavements and base soils.
Asphalt and aggregate are non-renewable resources. Mining quality aggregate and opening new quarries has its problems. The very roadway we wish to rehabilitate may already possess the best available aggregate. Why pick it up and remove it?
There are many factors to be considered in any construction process. They are planning, logistics, cost, product quality and responsibility. Responsibility for the pavement means cost savings if you recycle the pavement and the environmental impact of using 100% of the old deteriorated asphalt to accomplish this.
The environment is everyone's responsibility, from the government official to the general public. Recycling makes good common sense. It provides a cheaper, faster and less disruptive alternative to conventional methods of reconstruction. It also saves time during construction and time to the traveling public. There is little material hauling and the cost savings can be very attractive.
ARRA has just recently spent two years producing the Basic Asphalt Recycling Manual (BARM) endorsed by the Federal Highway Administration. The BARM will introduce road managers to the recycling technologies that are available today. This 270-page book on the ARRA disciplines covers each discipline from historic information, pavement assessment, structural capacity, material properties, geometric, traffic, economic and environmental assessments. It also provides mix design, blending charts, method specifications, end results specifications, inspection, quality control and quality assurance.
The unique feature of any aged asphalt roadway is its ability to be reused and bought back to its original or near original consistency. With the present equipment, recycling agents, know-how and technology, any existing aged and deteriorated asphalt pavement can be recycled and restored. Recycling of our natural resources has always been considered good economic practice and good common sense. Today it is even more important because our natural resources are drying up--and our highway funding is too.
