Evaluation of the relative field permeability of Superpave in Tennessee

This paper presents the results of a study initiated to evaluate the relative permeability of Superpave^TM-designed mixes placed on the roadway in Tennessee The study consisted of using a tiered field permeameter developed by the National Center for Asphalt Technology (NCAT) Four Superpave^TM-design mixes constructed m 1999, 4 Marshall-designed mixes constructed in 1999, and 8 Superpave^TM-designed mixes constructed prior to 1999 were tested in this study

The primary focus of this study was to evaluate the correlation between field permeability test results and in-place density of Hot Mix Asphalt (HMA) To achieve this goal, field permeability tests and the in-place density tests were conducted at each project. Linear regression analysis was then used to evaluate the relationship between field permeability. Voids in the Mineral Aggregate (VMA), Voids Filled with Asphalt (VFA), nuclear density (%G_mm), and core density(%G_mm). The field permeability measurements for the Superpave^TM-designed mixes were also compared to those of the conventional 75-blow Marshall-designed mixes

The results presented herein demonstrate that a good relationship exists between field permeability and in-place density This study documents the importance of achieving adequate in-place density on the roadway during construction and exhibit how in-place density can be directly correlated to field permeability of HMA