Non-destructive evaluation of concrete by the quality factor

Measurement of the longitudinal P-wave propagation velocity is a commonly used test for the non-destructive evaluation of concrete. However, the pulse velocity is not always a good indicator of the quality of concrete. This paper concerns the application of ultrasonic wave attenuation as a tool for evaluating concrete. A spectral ratio technique is used to determine the quality factor, a non-dimensional parameter that characterizes ultrasonic wave absorption in a material. The experimental study carried out on different types of concrete and described herein shows that this factor is more sensitive to the variation of mechanical properties of concrete as well as to the formation and growth of microcracks in concrete.