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. [ABSTRACT FROM AUTHOR]