DECEMBER 2010
                                        

Green roads: rubberized asphalt paves the way to a greener future in California

California recycles 75 percent of its waste tires every year.

Tires that are no longer road worthy are a valuable resource when recycled. In California, nearly 42 million waste tires were generated last year, and most were converted into new, higher-value products that help boost the state’s economy. Unfortunately, the remaining 25 percent – about 11 million waste tires last year alone – ended up in landfills or stored illegally. When stacked side by side, that’s enough tires to stretch the length of the West Coast from Mexico to Canada.

The Department of Resources Recycling and Recovery (CalRecycle) offers local governments grants and technical advice about how to put recycled tires to use as cost-effective and green alternatives to traditional paving and construction fill materials.

Rubberized asphalt concrete (RAC) consists of crumb rubber ground from waste tires that is mixed with asphalt and other aggregate. This mixture forms a durable alternative to traditional asphalt. RAC requires fewer repairs than regular pavement, is skid resistant, reduces noise, and is a green alternative because it uses 2,000 waste tires for every paved lane-mile.

Because rubberized pavement lasts longer, RAC roads also result in fewer greenhouse gas emissions associated with repairs, and less noise pollution due to long-lasting noise reduction properties.

“RAC is truly a green alternative that makes sense economically and environmentally,” said Jerry Dankbar, street maintenance superintendent. “Our community has benefitted from roads that need fewer repairs, and are safer. The city of Roseville is pleased our RAC roads reduce waste and save resources for future generations.”

Tire-Derived Aggregate (TDA) is another ecologically friendly product made from shredded waste tires. It is used in a variety of public works projects to replace naturally mined materials like gravel.

TDA is cheaper and lighter than gravel, has superior drainage properties, and reduces noise and vibration when used in light-rail projects. Not only does using TDA reduce costs, it also keeps thousands of waste tires out of landfills with every application. When used in place of mined aggregates, it preserves natural resources and landscapes. In addition, twice as much TDA can be transported in a single truckload, when compared to gravel, requiring fewer trucks, less fuel and lower emissions with every TDA project.