Assessment of Mechanical Properties of Concrete by Combining Digital Image Correlation and Ultrasonic Pulse Velocity

The ultrasonic pulse velocity (UPV) method is widely used for determining the dynamic modulus of elasticity of concrete. Traditionally, this approach requires assuming Poisson’s ratio (arbitrary values ranging from 0.1 to 0.25), regardless of the actual properties of the tested material. Such assumptions can lead to inaccurate estimations of the elastic modulus and limit the reliability of the method. In this study, an experimental methodology is proposed to enhance the accuracy of the estimation of the elastic modulus of concrete by combining digital image correlation (DIC) with UPV testing. The DIC technique is used during axial compression tests to directly measure the Poisson ratio of cubic concrete samples, while the dynamic modulus of elasticity is determined through UPV measurements. Subsequently, conversion models from the literature were applied to estimate the static modulus of elasticity from the dynamic modulus. The obtained values are compared with the experimental measurements of the static modulus, showing strong consistency and validating the proposed approach. The results highlight two key findings: (i) incorporating the actual Poisson ratio of the material significantly improves the precision of modulus predictions obtained via UPV, and (ii) DIC provides a reliable and adaptable tool for measuring Poisson’s ratio in concrete. Overall, the integration of DIC and UPV offers a robust and non-destructive framework for improving the assessment of mechanical properties of concrete.