Evaluation of Elastic Anisotropy of Concrete Using Ultrasound Wave Propagation

The aim of this study was to test the isotropic behavior hypothesis for concrete by means of wave propagation tests. The elastic properties of the concrete were determined using ultrasound tests with 1.0 MHz longitudinal and transversal transducers in polyhedral specimens with 26 faces. The concrete was analyzed using the theoretical aspects of three types of elastic behavior, namely isotropy, transverse isotropy, and orthotropy, in concretes with different compressive strengths and coarse aggregate size distributions. The results show that there were no statistically significant differences in the elastic parameters on the three symmetry axes. The constitutive relation between the shear modulus and longitudinal modulus, which involves Poisson's ratio, was as expected for isotropic materials, and the elastic properties of the concrete differed equally as a function of the compressive strength. Considering the results, the isotropic behavior of the concrete was validated regardless of the elastic behavior adopted in the analyses. (AU)