Characterization of the adhesive and cohesive moisture damage for asphalt concrete

Durability of asphalt concrete is significantly influenced by moisture damage, resulting in early degradation of asphalt pavements. There are several tests and conditioning methods adopted by agencies and researchers to identify the susceptibility of asphalt mixtures to the moisture damage. However, there is a need to develop predictive models that account for the impacts of moisture on fundamental mechanistic properties of asphalt concrete. In this regard, the focus of this paper is to develop an adhesive and a cohesive moisture damage model that enable the prediction of the amount of induced damages due to the moisture diffusion in the asphalt concrete. The models are developed based on intermolecular bond energy/force, and the mechanisms of cohesive and adhesive failures. They assume water vapor diffusion as the dominant moisture transport mode in asphalt pavements. The models are calibrated and validated by conducting dynamic modulus test on Fine Asphalt Matrix mixtures as well as Bitumen Bond Strength test on the adhesive bond between aggregate and asphalt binder. The results of validation process show the competence of the proposed models in predicting the adhesive and cohesive moisture damage of asphalt mixtures. (C) 2020 Elsevier Ltd. All rights reserved.