Selection and evaluation of field permeability device for asphalt pavements

Results of a study conducted to select, standardize, and evaluate a device to estimate the in-place permeability of hot-mix asphalt (HMA) pavements are presented. The study consisted of evaluating four different field permeameters in order to select and standardize a device that was correlated with laboratory permeability results, would provide repeatable results, and was easy to use. Additional testing on five HMA pavements was conducted with the selected device in order to evaluate the relationship between in-place pavement density and field permeability. The study entailed visiting three ongoing construction projects and conducting field permeability tests on newly compacted HMA pavements with each device. Also at each project, cores were obtained from which the laboratory permeability was determined. The data from each project were analyzed to determine which field permeameter correlated best with laboratory permeability, provided the most repeatable results, and was easy to use. Results of this study indicated that two permeaters did not show significant differences in results when compared with laboratory permeability results and had approximately the same amount of repeatability. For this reason, a field permeameter was selected on the basis of ease of use. This selected device was then taken to five additional HMA construction projects. At each project, field permeability testing was conducted, and the in-place density of pavements was obtained from cores. Relationships between in-place air voids and field permeability for all five projects were good: R2-values ranged from 0.63 to 0.82.