Towards an alternate evaluation of moisture-induced damage of bituminous materials

Abstract

Moisture-induced damage is widely known to cause multiple distresses that affect the durability of constructed pavements and eventually lead to the costly maintenance of pavement structures. The reliability and practicality of the assessment protocol to evaluate moisture susceptibility of flexible pavements presents a dilemma within the asphalt community that arises from the complexity and interrelation of moisture mechanisms in the asphalt-aggregate system. Researchers worldwide are continuously trying to develop suitable evaluation methods to simulate the combined destructive field-induced effects of moisture in the laboratory to help practitioners identify and alleviate this complex problem. The main objective of this article is to provide insights and highlight the challenges and opportunities of this important topic in order to extend and share knowledge towards finding a realistic assessment protocol of moisture damage in the laboratory. Two scenarios are proposed in this article: (1) a damage rate concept that accounts for the change of mechanical property (e.g., indirect tensile strength) with respect to the conditioning time, and (2) the establishment of a database using a surface free energy concept to help stakeholders select appropriate asphalt-aggregate combinations without the need to run additional moisture susceptibility tests.