Experimental study of wave propagation in heterogeneous materials

The phenomenon of wave propagation through concrete materials is affected by dispersion due to its intrinsic heterogeneous microstructure. Previous experiments have shown an increase of phase velocity at high frequencies. This behaviour cannot be analytically described by the classical elasticity theory, due to its non-dispersive nature. Instead, enhanced theories can be adopted. In this work the dynamically consistent non local model, able to take into account the microstructural effects by two additional length scale parameters, is retrieved. The main subject of this contribution is the experimental identification of the dispersive behaviour of cementitious materials and the validation of the gradient continuum to predict the dispersion of the wave born out of the heterogeneity of the material. The proposed work extends the applicability of non-local theories from a purely heoretical/analytical domain to the laboratory territory.