Characterization of concrete behavior under cyclic loading using 2D digital image correlation

The development of plastic deformations of concrete during loading-unloading cycles and post cracking behavior must be carefully controlled for accurate modeling of concrete structures. This study aims to validate the use of digital image correlation (DIC) for characterizing concrete behavior under loading-unloading conditions. Experimental tests were conducted on cubic and cylindrical concrete specimens, employing strain gauges and DIC methods. Uniaxial compressive static and loading-unloading tests were performed on two series of concrete with different compressive strengths to establish stress-strain relationships.The experimental results demonstrated good agreement between strain gauges and DIC measurements in the elastic range for both cylindrical and cubic specimens. Analytical and numerical modeling further confirmed the accuracy of permanent strains obtained through DIC for the cubic specimens subjected to cyclic loading beyond the elastic domain. Based on these findings, it can be concluded that the DIC technique is reliable for tracking strain evolution up to the point of material failure under uniaxial loading-unloading compression.