Rubberized asphalt
Encyclopedia
Rubberized asphalt concrete (RAC), also known as asphalt rubber or just rubberized asphalt, is pavement
material that consists of regular asphalt concrete
mixed with crumb rubber
–ground, used tires that might otherwise be discarded, taking up space in landfills, if they were not re-directed for use as tire derived fuel
in power plants or other recycled rubber products. Asphalt rubber is the largest single market for ground rubber in the United States, consuming an estimated 220 million pounds, or approximately 12 million tires annually.
Use of rubberized asphalt as a pavement material was pioneered by the city of Phoenix, Arizona
on several area freeways in the 1960s because of its high durability. Since then it has garnered interest for its ability to reduce road noise.
In 2003 the Arizona Department of Transportation
began a three-year, $34-million Quiet Pavement Pilot Program, in cooperation with the Federal Highway Administration
to determine if sound walls
can be replaced by rubberized asphalt to reduce noise alongside highways. After about one year, asphalt rubber overlays resulted in up to a 12-decibel reduction in road noise, with a typical reduction of 7 to 9 decibels.
Arizona has been the leader in using rubberized asphalt, but California
, Florida
, Texas
, South Carolina
, Nevada
, and New Mexico
are also using asphalt rubber. Tests are currently underway in other parts of the United States
to determine the durability of rubberized asphalt in northern climates, including a 1.3 mile stretch of Interstate 405
in Bellevue
and Kirkland
, Washington and a handful of local roads in the city of Colorado Springs, Colorado. In Belgium, tests in the ring of Brussel and in the F1 circuit of Francorchamp (see the film by Jean-Marie Piquint RUBBERIZED ASPHALT for Esso Belgium).
Pavement (material)
Road surface or pavement is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past cobblestones and granite setts were extensively used, but these surfaces have mostly been replaced by asphalt or concrete. Such...
material that consists of regular asphalt concrete
Asphalt concrete
Asphalt concrete is a composite material commonly used in construction projects such as road surfaces, airports and parking lots. It consists of asphalt and mineral aggregate mixed together, then laid down in layers and compacted...
mixed with crumb rubber
Crumb rubber
Crumb rubber is a term usually applied to recycled rubber from automotive and truck scrap tires. During the recycling process steel and fluff is removed leaving tire rubber with a granular consistency. Continued processing with a granulator and/or cracker mill, possibly with the aid of cryogenics...
–ground, used tires that might otherwise be discarded, taking up space in landfills, if they were not re-directed for use as tire derived fuel
Tire derived fuel
Tire-derived fuel is composed of shredded tires. Tires may be mixed with coal or other fuels such as wood to be burned in concrete kilns, power plants, or paper mills...
in power plants or other recycled rubber products. Asphalt rubber is the largest single market for ground rubber in the United States, consuming an estimated 220 million pounds, or approximately 12 million tires annually.
Use of rubberized asphalt as a pavement material was pioneered by the city of Phoenix, Arizona
Phoenix, Arizona
Phoenix is the capital, and largest city, of the U.S. state of Arizona, as well as the sixth most populated city in the United States. Phoenix is home to 1,445,632 people according to the official 2010 U.S. Census Bureau data...
on several area freeways in the 1960s because of its high durability. Since then it has garnered interest for its ability to reduce road noise.
In 2003 the Arizona Department of Transportation
Arizona Department of Transportation
The Arizona Department of Transportation is an Arizona state government agency charged with facilitating mobility within the state. In addition to managing the state's highway system, the agency is also involved with public transportation and municipal airports...
began a three-year, $34-million Quiet Pavement Pilot Program, in cooperation with the Federal Highway Administration
Federal Highway Administration
The Federal Highway Administration is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two "programs," the Federal-aid Highway Program and the Federal Lands Highway Program...
to determine if sound walls
Noise barrier
A noise barrier is an exterior structure designed to protect sensitive land uses from noise pollution...
can be replaced by rubberized asphalt to reduce noise alongside highways. After about one year, asphalt rubber overlays resulted in up to a 12-decibel reduction in road noise, with a typical reduction of 7 to 9 decibels.
Arizona has been the leader in using rubberized asphalt, but California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, South Carolina
South Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, and New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
are also using asphalt rubber. Tests are currently underway in other parts of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
to determine the durability of rubberized asphalt in northern climates, including a 1.3 mile stretch of Interstate 405
Interstate 405
Interstate 405 may refer to:* Interstate 405 , a bypass of Los Angeles, California* Interstate 405 , a loop in Portland, Oregon* Interstate 405 , a bypass of Seattle, Washington...
in Bellevue
Bellevue, Washington
Bellevue is a city in the Eastside region of King County, Washington, United States, across Lake Washington from Seattle. Long known as a suburb or satellite city of Seattle, it is now categorized as an edge city or a boomburb. The population was 122,363 at the 2010 census.Downtown Bellevue is...
and Kirkland
Kirkland, Washington
Kirkland is a city in King County, Washington, United States. It is a suburb of Seattle on the Eastside . The population was 48,787 at the 2010 census makes it the 9th largest city in King County and the 20th largest city in the state...
, Washington and a handful of local roads in the city of Colorado Springs, Colorado. In Belgium, tests in the ring of Brussel and in the F1 circuit of Francorchamp (see the film by Jean-Marie Piquint RUBBERIZED ASPHALT for Esso Belgium).
External links
- Arizona Department of Transportation Quiet Pavement Pilot Program
- Asphalt Rubber Usage Guide, from California Department of Transportation