Wave dispersion and attenuation in fresh mortar: theoretical predictions vs. experimental results

In the present paper, the dispersive and attenuative behavior of fresh cementitious material is examined through a series of ultrasonic, through-transmission measurements. The sand size and content dominate attenuation behavior, while the effect of entrapped air bubbles is mostly obvious at lower frequencies elevating phase velocity to values much higher than that of water. Theoretical investigation seems to explain the observed dispersion and attenuation mainly through two scattering interactions: sand embedded in paste and air bubbles in mortar. The predictions made by scattering theory follow closely the experimental data. The possibility of material characterization is discussed.