Correlation between the Laboratory and Field Permeability Values for the Superpave Pavements

Permeability affects the performance of Superpave pavements. Percolation of water, through the interconnected voids of an asphalt pavement, causes stripping of the asphalt-bound layer as well as deterioration of the foundation layers of the roads. In this study, laboratory and field permeability tests, based on the principles of falling head, were conducted on different Superpave mixes with 19 mm and 12.5 mm nominal maximum aggregate sizes and coarse and fine gradations, to study the correlation between the laboratory and the field permeability values. The objective was to assess whether the field permeability values could be estimated during the mixture design process so that mix design can be adjusted depending upon the degree of permeability desired. The results show that there was a significant difference between the laboratory- measured and the field permeability values. The field permeability values were very high compared to the laboratory-permeability values. The reason behind this discrepancy was further investigated and explained in this paper. Nevertheless, the field permeability values were found valuable in assessing compaction quality of the Superpave pavements.