Impacts of Moisture on Asphalt Properties

Moisture susceptibility has been recognized as a major pavement distress since the early 1990s. Great effort has been given in this field to come up with effective test methods to quantify the moisture susceptibility of asphalt concrete to take remedial action for the longevity of the structures. Even though the Mechanistic-Empirical approaches are being followed by many agencies, they inherit some limitations as they are not based on materials’ surface chemistries, which are predictors of moisture resistance. For an accurate prediction of moisture susceptibility, the mineral aggregates and asphalt binder interaction along with the physical test results should be considered. The proposed study will consider these shortcomings and develop a simple and meaningful tool to predict moisture-induced potentials of asphalts. Furthermore, a database of compatible aggregate-binder systems will be helpful for Arkansas State Highway and Transportation Department to proactively include/exclude any aggregates for a particular paving grade binder. As such, the main objective of this study is to establish an effective test protocol to quantify moisture susceptibility of asphalt mixture considering the surface chemistries and molecular level properties as well as aggregate-binder compatibility. The outcome of this project is expected to minimize premature stripping-related pavement failures and save taxpayers' money by adopting the most effective test method and compatible materials. The findings of the proposed study can be extended for other Departments of Transportation (DOTs) in Region 6.