Nondestructive Evaluation of Concrete Compressive Strength Using the Impact-Echo Method

This nondestructive technique involves obtaining the speeds of P-waves based on frequencies measured using the impact-echo method (IEM). Once the P-wave is generated, the sensor captures the horizontal displacement signal from the concrete surface. P-waves are used to estimate the compressive strength of concrete. Test results demonstrate that the velocity of P-waves is sensitive to changes in concrete strength at each age. This approach is capable of calculate the P-wave velocity with relative ease, thereby enabling the prediction of compressive strength. These measured values were used to verify the accuracy of the IEM. The proposed IEM was verified using concrete specimens produced with drilling-core for different strength grades. The results indicate that the proposed method can significantly enhance the preciseness of strength evaluation. Therefore, the P-wave based method is appropriate for in situ structures with features of portable, speed, convenience, and nondestructive of the proposed method.