DEVELOPMENT OF REPRESENTATIVE VOLUME ELEMENT FOR ELECTROMAGNETIC CHARACTERIZATION OF A HETEROGENOUS GEOMATERIAL

Electromagnetic (EM) analysis applied to structural geomaterials is a growing field of investigation for its significant potential in the field of non-destructive testing and characterization of the materials. Previous studies have simplified the multi-phase composition of geomaterials as layered structures, where each constituent material formed its own distinctive layer. While conclusions from such experimental studies were effective in detecting changes in EM responses, the methods of modeling heterogeneous, multi-phase structures were not be as representative of geomaterial composition like an aggregate-matrix model. A study was conducted to reveal discrepancies in EM responses of laminar and aggregate-matrix models. The laminar and heterogenous matrix models were compositionally equivalent with respect to the constituents present. Scattering parameter responses were recorded as a function of frequency for two-port systems; the frequency range of investigation was 0 to 25 GHz. Significant discrepancies in the responses were evident with no immediately apparent relationships between the responses. This conclusion prompted the need to further investigate the influences of a model's geometric parameters on its EM response. The geometric parameters investigated here were the centroid positioning of the aggregates and the size of the material element simulated. The goal was to evaluate the extent of the parameters' influences to identify criteria for an EM Representative Volume Element in their respect.