| Dielectric properties of cementitious materials (cement paste, cement mortar, and concrete) are key to the success of radar sensors in civil engineering. They are used in the condition assessment of civil engineering structures as the basis of radar nondestructive testing (NDT) methods. In this thesis, the input dielectric data was collected using an open-ended coaxial probe at room temperature (21-25°C) with 25-30% relative humidity by Solak (2011) before and after oven-drying. Three homogeneous dielectric models and three heterogeneous dielectric models were applied to both oven-dried and room-conditioned hydrated cement paste panels. Homogeneous dielectric models include Debye's model, Havriliak-Negami's model and Yu's model (only for oven-dried) (2009). Yu's model provides the best overall performance on oven-dried cement paste panels, among three homogeneous models. Havriliak-Negami's model were in good agreement with experimental results for room-conditioned cement paste panels. On the other hand, heterogeneous models include Maxwell-Garnett's model, Wiener's model and Polder-van Santen's model. In heterogeneous models, the shape of inclusion materials shows significant influence on modeling results. In addition, it is found that Polder-van Santen's model has good potential on modeling the dielectric properties of hydrated cement paste panels. |
