Field and laboratory investigation of permeable asphalt mixes on Georgia highways

The Georgia Department of Transportation (GDOT) investigated possible high permeability in asphalt mixes statewide in response to reports of prolonged wetness on pavements around the state after rainfall. In these locations, high permeability manifested itself as wet areas on pavement surfaces where wetness remained after natural conditions should have removed all moisture from the surfaces. Sixteen project sites were inspected for problem areas statewide, and core specimens were taken from six of the sites. Specimens were taken from areas considered representative of the problem areas in each project. The specimens were tested to determine the permeability, bulk specific gravity, maximum theoretical specific gravity, percentage of air voids, percentage of asphalt cement, and gradation of the mix. According to the findings of this investigation, some Superpaver; mixes that were designed in accordance with GDOT specifications exhibited undesirable permeability. The investigation determined that both mix de...