Strain and deflection analysis in plain concrete beams and reinforced concrete beams by applying digital image correlation

Throughout history invasive methods for analyzing deflections and deformations have been used in concrete structures at the laboratory, but the advancement of technology has allowed the development of new non-invasive alternative methods such as Digital Image Correlation (DIC). With this technique, it is possible to obtain information about the deflections, strains and strain fields in a structure. The current study consists of performing a flexural test on plain concrete beams and concrete arches reinforced with FRP reinforcement. All tests were recorded with a cheap, small camera, then transferred into a series of images in order to apply the digital image correlation technique. The analysis with DIC results in the displacements, strains and strain fields of the surface under analysis. Finally, the percentage of error between the displacement derived from the DIC technique and the displacement measured by Linear Variable Differential Transformers (LVDTs) is calculated. In conclusion, the study shows that it was not possible to reach accuracy on the values of deflections and strains by the applied method and that a higher-speed camera is necessary to capture the moment of failure.