Different Approaches to Develop Permeability Specifications of Asphalt Pavements

Moisture damage of asphalt concrete pavements is affected significantly by water permeability. Therefore, permeability specifications were developed by different states and agencies so that they can be controlled during mix design or the construction process. However, those specifications are mostly based on laboratory permeability tests on field-collected cores. This study determines whether permeability specifications based on other test results (field permeability tests on field, laboratory permeability tests on gyratory compacted samples) and correlations (permeability vs. total pores, permeability vs. permeable pores) can be developed. It is observed that the critical permeability value obtained using gyratory compacted samples is 100E-5 cm/s. The specific value obtained using laboratory permeability of field cores and total pores tests is 125E-5 cm/s. This value rises to 320E-5 cm/s if permeable pores are used instead of total pores. A critical permeability value cannot be obtained using field permeability test results. Therefore, the field permeability test is not useful to confirm permeability specification of a pavement.