Pavement Preservation Journal, Summer 2015, Vol. 8, No. 2
By Russell Heritage
Georgia’s interstate system has some of the highest quality pavements money can buy: open graded friction courses (OGFCs).
These mixes make excellent wearing surfaces due to their high friction properties and surface permeability. OGFCs are much safer to drive on during heavy rainfall than dense graded surfaces because the mixture is designed to significantly reduce vehicle spray. The tradeoff is this same property makes OGFCs susceptible to raveling, particularly in areas that experience frequent snow, ice and areas of severe sunlight.
They are also expensive to maintain. In the case of I-475 south of Atlanta, just like many other roads across the country, there simply wasn’t enough money in the state’s budget to repave the aging roadway. As it reached 12 years of service life, I-475 experienced preliminary raveling, and in some places, total section loss. Georgia DOT needed a way to preserve approximately 90 lane-miles of the six-lane road until it could afford a more long-term solution.
Funding wasn’t the only issue the agency faced. Safety was also a major obstacle to the substantive repair of this pavement. I-475 is a busy interstate route, and dense, high-speed traffic makes repair work a dangerous job, and would require any preservation product to support a quick return to traffic. With these concerns, a rejuvenating fog seal was specified to preserve the pavement, chosen due to ease of application and its low cost versus a micro mill and inlay project.
