AN EVALUATION OF FACTORS AFFECTING PERMEABILITY OF SUPERPAVE DESIGNED PAVEMENTS

Abstract

Recent research has shown that coarse graded Superpave mixes can be excessively permeable to water at air void levels around 6%. The aims of this study were to evaluate the permeability of Superpave designed mixes used by the Maine Department of Transportation and determine the effect of gradation, lift thickness, and in-place density on the permeability of these mixes. Both field and laboratory tests were conducted. On the basis of results obtained in this work, several conclusions are outlined and discussed. A main recommendation is that State Departments of Transportation consider designing mixes to be placed 100 mm below the pavement surface on the fine side of the maximum density line. It is thought that this will make these mixes less permeable than coarse graded mixes at similar void levels and thus less susceptible to allowing moisture or moisture vapor to propagate upward through the pavement structure.