Comprehensive dielectric model of cement concrete including frequency and temperature

The dielectric properties of cement concrete are not only related to the dielectric properties and volume ratio of each component, but also related to frequency and temperature. In order to analyse these influencing factors, a dielectric constant test was done in the laboratory. Experimental results show that the dielectric constants decrease linearly with increase of temperature and decreases exponentially with the increase of frequency. Based on the experimental rules, a new dielectric model including frequency and temperature is established and verified by experiments. The verification results show that the calculation accuracy of the comprehensive dielectric model after considering the influence of frequency and temperature is improved by 25.5%, which meets the requirements of engineering detection accuracy. The model is applied to engineering practice, and the calculation methods of pavement structural layer thickness and moisture content are developed. The results show that the comprehensive dielectric model established in this paper has smaller error and higher accuracy. Using this dielectric model, the data conversion between different frequency and temperature can be achieved. The research results of this paper can provide a reference and basis for the quality evaluation of concrete structures.