By: Michael L. Polak
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.
About The Author: Polak is president of the ARRA, Annapolis, Md.
