Mohave County has found a new way to save taxpayers money by using recycled tires to help chip seal roads. It is estimated that this new method will extend the life of County roads by up to 40%. The Mohave County Public Works Department completed their first 7.2 miles of using rubberized chip seal technology earlier this year, and anticipate more chip sealing projects to be done around the county using the same method. “This method uses recycled tires to extend the cost per service life of a chip seal,” Supervisor Buster Johnson stated. “The normal service life of a chip seal is 7 years. By using a rubberized chip seal method, our Public Works Department can extend the life of chip seals upwards to 10 years or more,” Johnson continued.
Aside from saving on the service life of a road, another advantage of using this new method is the noise reduction. “Anyone who drives on a road that has been chip sealed using rubberized asphalt will notice a major difference,” Johnson stated. “These roads are a lot smoother than roads chip sealed using conventional asphalt-overlay. The smoothness of the road will not only make it a quieter ride for drivers, but it will also put less wear and tear on vehicle tires who will no longer have to go over the crakes and bumps seen with traditional chip sealing projects,” Johnson explained.
According to Public Works Director, Steve Latoski, the County’s rubberized chip seal method is done by using a polymer asphalt rubber binder. “This method provides a durable pavement structural resurfacing, through a proven and innovative Polymer Modified Asphalt Rubber (PMAR) binder surface treatment known as Fractured Aggregate Surface Treatment (FAST) configured for high volume roads,” Latoski explained. “These treatments act as a stress absorbing membrane to limit proliferation of reflective cracking from the underlying pavement surface layer, resist water infiltration into the pavement structure base and subgrade and maintain a longer surface life than conventional chip seal applications,” Latoski continued.
Latoski went on to explain that while the material used in the rubberized chip sealing method was initially a bit more expenses than with conventional asphalt overlay, the cost per service life is reduced making the service life gain exceed that of the initial cost. “Rubberized chip sealing is accomplished by putting the ground up rubber from recycled tires into the oil. That is than put into the asphalt. This combination enhances the lifetime of the chip seal tremendously by making it more flexible,” Latoski stated.
County roads paved with conventional asphalt require some sort of maintenance every few years. “Because of the resistance to cracking and aging exhibited by rubber-modified asphalt, roads paved with this cost efficient application generally experience longer service lives before maintenance,” Latoski said. “Not only does rubber-modified asphalt exhibit more elasticity than unmodified asphalt, but it also shows a greater resistance to aging. This anti-aging effect is the result of anti-oxidants contained in the scrap tires,” Latoski continued.
The first road paved in the County with this new method was done earlier this year. The county paved 7.2 miles of Piece Fairy Road from the U.S. 93 and East towards Dolan Springs. All 7,500 recycled tires for the project came from Mohave County and were used as the crumb rubber ingredient in the binder. “This is a high volume area especially with all the tour buses now going to Grand Canyon West,” Supervisor Buster Johnson stated. “By using this method we are not only saving taxpayers money on the service life of these roads, but we are also putting old tires, that would otherwise end up in landfills, to good use,” Johnson ended.