Polymer Strength Prediction Model Based on Dielectric Constant

To reveal the relationship between the dielectric constant and mechanical strength indices of polymer grouting materials, 40 groups of specimens with different densities were designed and prepared in the laboratory. The complex dielectric constants of the specimens within the frequency range of 500–6000 MHz were measured using a vector network analyzer (VNA) equipped with the open‐ended coaxial probe. Based on the experimental data, relationship equations for the dielectric constant and conductivity as functions of density were constructed. Compared to conductivity, the dielectric constant was found to be less affected by frequency. By incorporating the results of engineering mechanics tests while using density as an intermediate medium, a mechanical performance index model based on dielectric properties and conductivity was developed. The study found that there are linearly increasing relationships with different increments between the bending strength, unconfined compressive strength, tensile strength, shear strength, shear modulus, and the dielectric constant and conductivity. Based on the research findings of this paper, the mechanical properties of polymers can be predicted through nondestructive testing technology using electromagnetic waves.