Crack Detection and Measurement Utilizing Image-Based Reconstruction

Image-based reconstruction for automated crack detection has been on the rise for the past decade or so; this new technology can be applicable to many different areas such as laboratory testing, field inspections, construction quality control and quality assurance, and post disaster reconnaissance. An added feature to automated crack detection is the ability to perform digital crack measurements with increased safety. Crack detection during experimental testing may require researchers to mark cracks on the specimens, whereas researchers can take photographs of the specimens from a safe distance and have the reconstructed model digital crack detection. Automated crack detection along with digital crack measurements will increase the quantity of cracks observed and measured. Increased quantity could reduce cost of field inspections by reducing inspection time. Compared to traditional crack measurement techniques such as a crack detection pocket microscope (crack scope) or crack width card (also referred to as a crack width gauge), safety would be less of a concern since photographs for image reconstruction can be taken at a distance rather than having to be directly against the structure; both of these traditional tools can be seen in Figure 1. Safety is a major concern in post disaster reconnaissance; after an event such as an earthquake or tsunami, structures have to be examined to determine the extent of damage. By utilizing image based reconstruction, assessments can be made without placing the inspector or engineer in dangerous situations.