Formulation of a new micromechanic model of three phases for ultrasonic characterization of cement-based materials

The objective of multiphasic models applied to cement-based materials is to estimate the global elastic constants as a function of properties of their constituents. However, these models have limited success for porosity characterization.In this investigation, a new approach that determines the elastic properties of three-phase materials is presented. The proposed model takes into account the microstructural characteristics of the constituent phases, as well as their elastic properties. The micromechanical model of three phases is applied to mortar, considering the material composed by cement paste matrix and two types of inclusions, aggregate and pores. The influence of geometry and elastic properties of both inclusions on the ultrasonic velocity has been evaluated theoretically. The effect of the volume fraction of pores on the ultrasonic velocity is also presented.