The Rubberized Asphalt Concrete (RAC) Chip Seal Grant Program
The Rubberized Asphalt Concrete (RAC) Chip Seal Grant Program is a new grant program sponsored by the Department of Resources Recycling and Recovery (CalRecycle) that provides funds to agencies that use recycled tires when resurfacing roads.
There are many advantages to using rubberized asphalt versus conventional asphalt. RAC incorporates ground tire (crumb) rubber into the hot mix. Crumb rubber is ground or granulated rubber particles, which are derived from auto or light truck tires or other sources that use a high content of natural rubber. The wet process is typically used in rubberized asphalt within the State of California. The wet process mixes the rubber with the binder (80% asphalt cement / 20% crumb rubber) in a field blending unit prior to introduction at the hot mix plant.
Caltrans began experimenting with rubberized asphalt produced by the "wet process" in the 1970's and developed design criteria using roadway deflection testing that resulted in thinner overlay courses than conventional asphalt concrete. Research has shown that 4" of conventional asphalt can be replaced with 2" of rubberized asphalt to achieve the same fatigue life. In the early 1990s, Caltrans testing confirmed the reduced thickness design of a gap-graded mix and received approval from the Federal Highway Administration.
The stated advantages of Rubberized Asphalt Concrete are as follows:
- Rubber Cape sealing can extend the life of a street by 10-14 years.
- Rubberized Asphalt Concrete is highly skid-resistant, quieter and resists shoving and rutting if a gap-graded mix is used.
- Rubberized asphalt concrete is environmentally friendly. A two-inch resurfacing project can use approximately 500 waste tires per lane mile.
- Rubberized asphalt concrete provides excellent long-lasting color contrast for striping and marking.
- Rubberized asphalt concrete provides a long-lasting, durable pavement that resists reflective cracking.
RAC Grant Program funding in the amount of $189,902 was used to complete the following chip seal resurfacing projects:
- 34,264 square yards of East Gonzales Road from Rose Avenue to Rice Avenue
- 30,015 square yards of residential streets located within the Rose Park Neighborhood Community
- 24,561 square yards of residential streets located within the Ormond Beach Neighborhood Community
- 43,033 square yards of residential streets located within the Bartolo Square North Neighborhood Community
- 58,029 square yards of residential streets located within the Bartolo Square South Neighborhood Community
Completed RAC Grant Program funding in the amount of $250,000 been used to complete the following rubberized asphalt resurfacing projects:
- Approximately 5,700 tons of RAC on Ventura Road from Gonzales Road to Wagon Wheel Road
- Approximately 7,250 tons of RAC on residential streets located within the Blackstock South Neighborhood Community
Management Analyst III