Moisture susceptibility of asphalt mixtures, Part 2: characterisation and modelling

Moisture damage in asphalt pavements is the degradation of the mechanical properties of the asphalt composite due to the action of water. In a companion paper the mechanisms of moisture damage were discussed. It was established that in order to characterise moisture damage in asphalt mixtures, it is important to comprehensively describe and model the effect of thermodynamic, chemical, physical, and mechanical processes. This paper discusses existing tests and analytical methods that can be used to assess and quantify moisture damage potential in asphalt mixtures. These methods range from visual qualification of asphalt binder stripped from the aggregate, to analytical-based models that include multiple material properties derived using fracture mechanics, continuum mechanics, thermodynamics, and/or micromechanics. In addition, this paper presents a new approach for classifying moisture damage, which emphasises recent analytical developments. Finally, advances in the mathematical modelling of moisture damage are summarised and future research efforts in this area are identified.