This study is focused on the electromagnetic characterization of concretes within the ground-penetrating radar frequency band. The evaluation of the complex dielectric properties is carried out in laboratory on 36 different concrete specimens defined by a specific experimental design. The composition parameters of the concrete mix design are the aggregate nature, the aggregate content, the cement nature, the cement content and the water to cement ratio (W/C). The model of relative permittivity associated to the experimental design is a multi-linear polynomial of the 5 chosen material parameters. The exploitation of this set of data consists in a calculation level of the coefficients of this model independently for the real and the imaginary parts of the relative permittivity. This reveals the significant relationship between the dielectric properties and the composition parameters. Raw results in terms of the real and imaginary parts of the dielectric permittivity along frequencies are presented for 36 different concretes in dry and saturated conditions and the sensitivity of the parameters are discussed.