Relationships among Gradation Curve, Clogging Resistance, and Pore-Based Indices of Porous Asphalt Mixes

ABSTRACT When properly designed, porous asphalt functions both to make safer the driving in wet condition, and to provide hydrologic restoration while functioning as a filtration interface. This study examined the role of aggregate granulometry both on the pore-based indices of porous asphalt and on the clogging resistance. Three groups of porous asphalt gradations comprised of 12 series of samples and separated based on gradation size indices have been examined. For all samples the vertical (kv) and horizontal (kh) permeability were measured with the commensurate total void contents (e) and total porosity (n). Also clogging resistance was evaluated by measuring hydraulic conductivity before and after 1 year of exposure of the samples to dust intrusion. Marshall tests were also performed in order to control the stability of the mixes. There was a strong relationship between the permeability and the void content. For a given aggregate gradation, each increment of asphalt content increase caused a decrement...