Asphalt Permeability Testing: Specimen Preparation and Testing Variability

Abstract

Concern over asphalt mixtures allowing surface water to enter has led to an interest in developing a reliable permeability test. Several studies have been conducted on permeability testing, and ASTM is currently developing a falling-head test method to determine asphalt permeability. The Virginia Department of Transportation became interested in testing its pavements and using permeability as a design consideration. An ASTM task group investigated the effect of sawing specimens, a technique for separating the layers of asphalt. Sawing did not lead to reduced permeability when the sawing process was properly controlled. Since a falling-head test might be used in acceptance and design specifications, it was important to determine its associated variability. Permeability variability was computed from test data derived from field cores and specimens prepared in the laboratory. Repeat tests by different operators indicated differences that warrant additional investigation.