“We tend to work in rural areas where there isn’t a high volume asphalt plant nearby. To reduce drive distance and to operate at the volumes we deal with, a portable plant works best for us.”—Mark Haines 40 in downtown Oklahoma City offered early examples of the benefits of perpetual pavements. First constructed in 1967, the sections withstood heavy traffic for more than 30 years. “Each of the sections has been overlaid, but the base course structure has not been touched,” the pamphlet reads. “Although they are 33 years old, they look like new.” Oklahoma’s first designed perpetual pavement project was completed in 2006 on SH-152. “That pavement is working and it’s changing minds,” said Larry Patrick, executive director of the Oklahoma Asphalt Pavement Association (OAPA). “SH152 is coming on 14 years old, and outside of a slide area and bridge approach issues caused by subgrade issues, the pavement has not needed any maintenance at all.” The perpetual pavement concept is one OAPA has been working hard to promote. “New ideas take time,” Patrick said. “There’s more interest in perpetual pavement than ever before in the state.”
Since Koss began the state’s second perpetual pavement project, Oklahoma has already seen the start and completion of its third perpetual pavement project, on the Kickapoo Turnpike east of Oklahoma City. The Oklahoma Turnpike Authority created the new turnpike to connect I-44 Turner Turnpike to I-40 to alleviate traffic in Oklahoma City.
FULL DEPTH ASPHALT
According to the National Asphalt Pavement Association (NAPA), the perpetual pavement concept relies on the use of multiple layers of asphalt to extend the useful
Permeable Friction Course, PG 76-28 (1.25”)
Stone Matrix Asphalt, PG 76-28 (2”)
14.25”
Base Mix (Polymer - Modified Asphalt), PG 76-28 (3.5”)
Base Mix, PG 64-22, 25 Percent RAP (4”)
Base Mix, PG 64-22, 25 Percent RAP (3.5”)
Local endangered wildlife limited Koss’ time frame to natural daylight hours. life of a roadway: “The pavement design begins with a strong, yet flexible bottom layer that resists tensile strain caused by traffic, and thus stops cracks from forming in the bottom of the pavement. A strong intermediate layer completes the permanent struc-
tural portion, and a final layer of a rut-resistant asphalt mix yields a surface that lasts many years before scheduled restoration.” For US-69, this was achieved in five lifts. The first lift was 4 inches of base mix with PG64-22 and 25 percent RAP, followed
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