Round-Robin Study for Field Permeability Test

Recently, a field permeability device and test procedure have been developed and tested by the National Center for Asphalt Technology (NCAT) that have shown the ability to identify pavement areas with high permeability to water. This device works by measuring the amount of water that flows into a pavement over a given time period by using a falling-head approach. Based on work conducted by NCAT, the use of this field permeability device has many potential benefits to the hot-mix asphalt industry. The field permeability device can be used as an almost real-time estimate of mat density and may be a good indicator of longitudinal joint quality. Because of the success NCAT has had with the device to date, a study was needed to evaluate the repeatability and reproducibility of the test method. Results of the round-robin study indicated that an estimate of permeameter–operator reproducibility was 10.0 × 10⁻⁵ cm/s. An overall standard deviation on permeability measurements was found to be 24.4 × 10⁻⁵ cm/s. Additionally, criteria were developed based on the variability of test results to specify field permeability testing for quality control type testing to ensure impermeable pavements.