Permeability of unbound base course layers in road foundations

The new Austrian standards for building those base layers admits larger amounts for grain size diameter 0,063 mm. The consequences are rather impermeable courses caused by unfavorable grain size distribution, although these layers have to be not frost-susceptible. Insitu tests are demanded to proof the water permeability of these foundation layers. A new insitu testing device is introduced and the theoretical and practical background is investigated. Uncombined base layers of different materials were compacted in an 1:1-model in the laboratory to verify the relation between density and water permeability.