Effect of the Interfacial Transition Zone on ultrasonic wave attenuation and velocity in concrete

Abstract

The effect of the Interfacial Transition Zone (ITZ) on ultrasonic wave attenuation and velocity in concrete is investigated in this study. These two parameters are often used to characterize the concrete microstructure. They can be analyzed through numerical simulations of wave propagation in concrete and validated with experimental data. However, a mismatch is noticed between the parameters estimated from numerical simulations and experimental measurements. This gap is addressed in this paper. It is shown that most of it can be explained by the Interfacial Transition Zone. Indeed, until now, numerical approaches for studying ultrasonic wave propagation in concrete considered perfect contact at the aggregate/mortar interface whereas real concrete exhibits imperfect contact at this interface. This paper presents a model which accounts for the physical properties of the Interfacial Transition Zone. The imperfect contact is modeled through a spring mass system and validated using data from experimental measurements.