Influence of aggregates and air voids on the ultrasonic velocity and attenuation in cementitious materials

Abstract

ABSTRACT This paper examines the influence of the size and volume fraction of both aggregates and air voids on the ultrasonic phase velocity and attenuation coefficient measured in cementitious specimens. A multiphase approach of the Waterman-Truell (WT) model was used to study theoretically how the size and volume fraction of the constituents in cementitious materials affect velocity and attenuation profiles. To verify the theoretical results obtained by the model, ultrasonic measurements were performed in several cementitious specimens with different granulometries of elastic aggregates (glass microspheres). Both theoretical and experimental results showed that velocity information can largely identify changes in the volume fraction of aggregates, whereas attenuation information is more sensible to variations in the aggregate size.