Georgia’s Experience with Recycled Roofing Shingles in Asphaltic Concrete

Abstract

Reuse of roofing shingle waste not only minimizes the environmental problems related to the disposal of waste in landfills, but also reduces the amount of virgin asphalt cement and fine aggregate required in hot mix asphaltic concrete (HMAC), thus creating the potential for cost savings. The Georgia Department of Transportation (GDOT) has experimented with the recycling of roofing shingles in HMAC by constructing two test sections in 1994 and 1995. The source of the roofing shingles used in both test sections was waste generated by a roofing manufacturer; this generally consisted of discolored or damaged shingles. One test section was constructed on Chatham Parkway in Chatham County and one on State Route 21 in Effingham County. GAF Building Materials, Inc., located in Savannah, provided the waste shingle material; APAC Georgia, Inc., also located in Savannah, produced and placed these experimental mixtures. To date, both test sections are performing well compared with the unmodified control sections. Based on the performance of these test sections, shingle manufacturing waste is allowed as a recycling material in HMAC, just as reclaimed asphalt pavement is, for GDOT projects. A specification allowing postconsumer roofing shingle waste to be used is also being proposed.