| dc.description.abstract | Most engineering as well as pavement materials are composites composed of two or
more components to obtain a variety of solid properties to support internal and external
loading. The composite materials rely on physical or chemical properties and volume
fraction of each component. While the properties can be identified easily, the volume
fraction is hard to be estimated due to the volumetric variation during the performance in
the field. Various test procedures have been developed to measure the volume fractions;
however, they depend on subjective determination and judgment. As an alternative,
electromagnetic technique using dielectric constant was developed to estimate the
volume fraction. Empirical and mechanistic approaches were used to relate the
dielectric constant and volume fraction. While the empirical models are not very
accurate in all cases, the mechanistic models require assumptions of constituent
dielectric constants. For those reasons, the existing approaches might produce less
accurate estimate of volume fraction. In this study, a mechanistic-based approach using
the self consistent scheme was developed to be applied to multiphase materials. The
new approach was based on calibrated dielectric constant of components to improve
results without any assumptions. Also, the system identification was used iteratively to
solve for dielectric parameters and volume fraction at each step. As the validation
performed to verify the viability of the new approach using soil mixture and portland
cement concrete, it was found that the approach has produced a significant improvement
in the accuracy of the estimated volume fraction. | en |
