Rapid real-time visualization method and system for crack initiation process of concrete component

A rapid real-time visualization method for a crack initiation process of a concrete component implemented through a visualization system, the visualization system comprising:

• a pressure test machine, a fluorescent solution spraying device, an ultraviolet (UV) lamp group, a visible light imaging device group, and a computer control system;
• wherein
• the fluorescent solution spraying device is configured to spray fluorescent excitation solution evenly to an observation surface of the concrete component,
• the pressure test machine is configured to apply a pressure load to the concrete component to crack the concrete component,
• the UV lamp group is configured to project UV lights onto the observation surface of the concrete component, with the UV lights projected by respective UV lamps of the UV lamp group fully covering the observation surface of the concrete component,
• the visible light imaging device group is configured to record a development process of cracks marked by the fluorescent excitation solution on the observation surface of the concrete component,
• the computer control system is connected to the fluorescent solution spraying device, the UV lamp group, and the visible light imaging device group, the computer control system is configured to control turning-on and turning-off of the fluorescent solution spraying device, the UV lamp group, and the visible light imaging device group, serve as a human-computer interaction interface to splice fields of view of respective visible light imaging devices of the visible light imaging device group into a whole, and visually display a crack initiation process of the cracks marked by the fluorescent excitation solution on the observation surface of the concrete component;
• the rapid real-time visualization method comprises following steps:
• S1, selecting the concrete component as a research carrier for a crack initiation process test based on a research purpose, placing the concrete component into the pressure test machine, and estimating a cracking load of the concrete component;
• S2, determining the observation surface of the concrete component in the crack initiation process of the concrete component, and evenly coating a fluorescent solution retention layer to the observation surface to make the observation surface of the concrete component wetted;
• S3, activating, by the computer control system, the fluorescent solution spraying device to spray the fluorescent excitation solution to the fluorescent solution retention layer until the fluorescent excitation solution adheres evenly to the fluorescent solution retention layer and reaches a critical state where the fluorescent excitation solution is about to flow vertically along the fluorescent solution retention layer;
• S4, activating, by the computer control system, the UV lamp group to project the UV lights onto the observation surface of the concrete component to make the UV lights fully cover the observation surface of the concrete component;
• S5, activating the pressure test machine to apply the pressure load to the concrete component, and simultaneously, activating, by the computer control system, the visible light imaging device group to record a video of a crack initiation process on the observation surface of the concrete component;
• S6, monitoring, by a monitor of the computer control system, the crack initiation process on the observation surface of the concrete component, wherein the computer control system automatically outlines a microcrack on the monitor for manual confirmation and emits an alert sound, when the microcrack meets microcrack determination criteria in crack propagation;
• S7, activating, by the computer control system, the fluorescent solution spraying device to perform supplemental spraying to a tip of the microcrack along a crack propagation direction of the microcrack after manually confirming the microcrack, and perform intermittent supplementary spraying to an area on the observation surface where the supplemental spraying is not performed from an end of the spraying;
• and
• S8, repeating the step S6 and S7 during a load applied process to the concrete component until the crack initiation process of the concrete component is completed, turning off, by the computer control system, the visible light imaging device group and the UV lamp group, and achieving a visual analysis and detection of the crack initiation process by reviewing the video.