Assessment of dielectrometry for characterization of processing and moisture absorption in FRP composites

The increasing use of ambient cured resin systems for the fabrication of composites used in structural components such as in civil infrastructure creates a need for monitoring cure progression over time as well as for tracking changes due to environmental exposure during the extended period of time needed to attain full cure. Further, there is a need for the development of methods to monitor the health of structures in the field for applications such as column retrofit, external strengthening of girders and slabs, and even bridge decks. This paper investigates the application of dielectrometry to the characterization of E-glass-epoxy composites exposed to deionized water. Results are correlated with DSC and moisture absorption. It is shown that a direct correlation between moisture absorption and permittivity can be obtained.