RUBBERIZED ASPHALT CONCRETE AND SLURRY
Rubberized Asphalt Concrete: Rubberized Asphalt Concrete (RAC) is produced when crumb rubber is blended with asphalt and aggregate material under specified conditions. Crumb rubber is usually made from recycled rubber that is ground and processed into small, uniform pieces. When appropriately used on road resurfacing projects, RAC has many advantages over conventional asphalt. For example, RAC is cost-effective, saving as much as $22,000 per lane mile over conventional asphalt projects. RAC also provides excellent long lasting color contrast for striping and marking, is highly skid-resistant, and uses more than 2,000 waste tires per lane mile, thereby conserving our natural resources and landfill capacity. These advantages have led the County to use RAC on approximately 75 percent of its resurfacing projects. This has made County of Los Angeles a leader in utilizing RAC to pave streets and highways.
Rubberized Emulsion Aggregate Slurry: Rubberized Emulsion Aggregate Slurry (REAS) is produced when crumb rubber is blended into asphalt emulsion at ambient temperature and used as a slurry to repair roadways. Although the cost of REAS is higher than for conventional slurry, the advantages include an approximate 50 percent increase in longevity, long lasting color contrast for striping and marking, and high skid-resistance. In addition, REAS uses more than seventy-eight waste tires per lane mile, thereby diverting waste tires from traditional disposal. To ensure the success of the Program and stimulate the market for waste tires through the slurry seal projects, the County Department of Public Works, in conjunction with Petrochem Marketing, Inc., developed specifications and testing criteria for the REAS material. As a result of the successful use of REAS, these specifications and testing criteria have been incorporated into the 1998 supplement of the Standard Specifications for Public Works Construction, commonly referred to as the "Green Book." [To date, more than 200 cities, counties, and agencies in the State have adopted the Green Book as their standard.] The County also aggressively identifies and awards contracts for the use of REAS on many road projects, funding millions of dollars in projects each fiscal year.