Comparative Evaluation of Moisture Susceptibility Test Methods for Routine Usage in Asphalt Mixture Design

Asphalt materials experience substantial amounts of environmental damage throughout their lives as surface layers in pavements. One of the most prominent forms of environmental damage, moisture-induced damage, is caused by the weakening of internal bonds of the material because of the presence of moisture in the voids of asphalt mixtures and is a common problem for asphalt pavements in wet climates. Moisture-induced damage is typically accounted for during asphalt mixture design by conducting performance tests to ensure the material is not susceptible to severe damage from moisture, although many of these methods have seen mixed amounts of success historically. The main objective of this study is to evaluate the ability of multiple asphalt mixture moisture susceptibility tests to identify good and poor performing mixtures with respect to moisture-induced damage to replace current mix design testing requirements. Ten plant-produced hot mix asphalt materials with established good and poor field moisture performance were subjected to various moisture susceptibility test methods. The results from these procedures are assessed to determine which procedure is most effective and practical as a moisture susceptibility test for routine usage during asphalt mixture design for transportation agencies. Results from this study suggest that performance tests with stiffness-based measurements, such as dynamic modulus paired with moisture conditioning and the saturated aging tensile stiffness procedure, show better correlation to field performance than traditional test methods such as AASHTO T-283, Standard Method of Test for Resistance of Compacted Asphalt Mixtures to Moisture-Induced Damage, and that the Hamburg wheel tracker test is the most effective and practical test method to reliably identify mixtures prone to experiencing moisture-induced damage.