Evaluation of dynamic modulus of elasticity of concrete using impact-echo method

This paper studies the validity of the impact-echo method for determining the dynamic modulus of elasticity of concrete. It is found that the P-wave speed obtained using the impact-echo method on standard specimens corresponds well with the theoretical one-dimensional P-wave speed. Also, the dynamic moduli obtained from the impact-echo method are essentially the same with those from the conventional transverse resonant frequency method. It is recommended that estimates of the dynamic modulus of elasticity should not be based on the static modulus alone.