The California asphalt paving industry is ever-changing and in order to provide the best services, asphalt paving companies are turning to new technologies to stay ahead of the competition.
Asphalt technology in California has been changing since the creation of Hot Mix Asphalt and will continue to change as time permits. Asphalt rubber pavement was introduced in 1991, which shocked many industry experts. Asphalt rubber pavement seemed promising to those in the industry who were ready for a change. On the other end of the spectrum were industry experts who thought that the world wasn’t ready for such technologies to be implemented.
In Tom Kuennens article titled, “Asphalt Rubber Makes a Quiet Comeback” shown in Better Roads Magazine, he describes rubber asphalt as, “a chemically reacted mix of liquid asphalt binder with 15 to 22% crumb rubber. The rubber is obtained from reclaimed tires, and added to liquid asphalt. It’s reacted at elevated temperatures prior to being mixed with aggregate.”
There are two types of asphalt rubber (wet process) are used in California. Type A- contains rubber only from ground tires, and Type B contains rubber from both ground tires and natural rubber. Caltrans seems to favor Type B binders because they have better resistance to reflection cracking and provide better stability. Rubber pavement disappeared for a few years due an increase in asphalt pavement technologies and a decrease in existing pavement costs associated with this form of material. Until recently, a number of important developments have helped propel asphalt rubber pavement to its current level of acceptance, including new tire-shredding technologies and the establishment of tire recycling facilities in every part of the United States.
In late 1994 the city of Los Angeles had the chance to repaved Olympic Boulevard with hot-mix asphalt which included 15% asphalt rubber millings from that same street.
How often will California use this material to law a quieter foundation for its streets?
Nobody knows. By decreasing noise on the highways, this asphalt technology gains ground with the transportation department of California. At the same time it also loses
popularity because of the negative byproducts it elicits, i.e., bad smell, smoke, and sticky material base.
Tom Kuennens also stated that, “The California’s Rubberized Asphalt Concrete Technology Center promotes the use of crumb rubber from scrap tires in roadway rehab projects by providing education, and consultation services to local agencies within California.”
To visit their website go to www.rubberizedasphalt.org