Thin shear crack observation of a cylinder structure test using image analysis

Crack marking in RC experiments is not only a labor intensive job but also carries a certain level of risk. Some cracks are too thin to be detected by edge-detection based methods. Public available image analysis software ImPro Stereo developed by the authors of this paper estimates the surface deformation by using image analysis. New formula has been added into ImPro Stereo in this work to estimate widths and sliding of shear cracks. This paper introduces the formula and presents its application to the crack development of a large-scale reinforced concrete experiment. The crack locations and widths are compared with labor pen marked cracks. The image analysis results not only generally match the crack marking, but also provide more details about crack development.