Mechanical Properties of Porous Asphalt Pavement Materials with Warm Mix Asphalt and RAP

The objectives of this paper are (1) to characterize the mechanical properties of porous asphalt pavement mixtures containing reclaimed asphalt pavement (RAP) and a WMA additive (Advera® WMA) using Superpave™ gyratory compactor and dynamic modulus testing. Four types of porous asphalt mixtures were evaluated in this study. They are 1) control mixture, a conventional porous asphalt mixture; (2) porous asphalt mixture with WMA additive (Advera® WMA in this case); (3) porous asphalt mixture containing 15% reclaimed asphalt pavement (RAP); and (4) porous asphalt mixture containing 15% RAP and additional WMA additive. This study evaluated compaction energy index (CEI), permeability, indirect tensile strength, and dynamic modulus ( E* ) for all types of porous asphalt mixtures. All of the porous asphalt mixtures meet the typical minimum coefficient of permeability in this study. Compaction energy required for the WMA containing 0.25% Advera® WMA was found to be lower compared with the control mixture (HMA). The results from the dynamic modulus test show that WMA made with 0.25% Advera® WMA had significantly lower values than the control HMA mixture. In addition, only a slight decrease in E* was found when WMA additive was added to the porous asphalt mixture containing RAP. For indirect tensile strength testing, WMA containing RAP was found to have the highest tensile strength among all of the mixtures tested.