Nondestructive Evaluation of Concrete Compressive Strength Using Shear-Horizontal Waves

Longitudinal (P) waves have been widely employed for estimating concrete compressive strength based on correlation models between wave velocity and strength. However, P-wave based methods show high uncertainty because of the challenge of identifying the weak first arrival of P waves and the sensitivity of P waves to air voids and moisture. Shear-horizontal (SH) waves are superior to P waves because of their velocity stability in concrete at various air void and moisture levels. Moreover, SH waves exhibit a high signal-to-noise ratio without mode conversion after reflection and refraction. In this study, an SH-wave based method was developed to measure the shear-wave velocity (Vs) of concrete directly using SH-wave transducers and then establish a correlation between Vs and compressive strength. The proposed method was verified using concrete specimens produced with four water-to-cement ratios and different strength grades. The results indicate that the proposed method can significantly improve the accuracy of first arrival identification and enhance the preciseness of strength evaluation. (C) 2022 American Society of Civil Engineers.