Analysis of moisture damage susceptibility of warm mix asphalt (WMA) mixtures based on Dynamic Mechanical Analyzer (DMA) testing and a fracture mechanics model

Warm mix asphalt (WMA) materials are asphalt mixtures fabricated with recently developed technologies designed to reduce the temperatures required to produce and compact traditional hot mix asphalt (HMA) mixtures. This study evaluates the moisture susceptibility of three WMA mixtures. The analysis is based on a viscoelastic-fracture model, which input parameters include results from the relaxation modulus and the Dynamic Mechanical Analyzer (DMA) test conducted on specimens representing the fine matrix portion of the actual mixtures, and from surface free energy tests. The results suggest that moisture caused more damage in two out of the three evaluated WMA fine mixtures in comparison to the damage observed in the control-HMA specimens. The results also reveal that the analysis should include not only the reduction caused by moisture of certain selected performance parameters, but the actual values of these parameters.