New infrastructure maintenance management support service that combines non-destructive inspection and augmented reality technology
Conventional concrete salt concentration investigation: Chalking + drilling method + chemical analysis
Salt damage to concrete is considered to be one of the main causes of deterioration. Due to the effects of anti-freezing agents and sea breezes, salt penetrates into the concrete and causes deterioration such as corrosion of reinforcing steel, so early countermeasures are required. Conventional concrete salinity measurement technology involves specifying the location where the salinity concentration is to be measured by chalking, obtaining sample powder by drilling, and measuring the salinity concentration by chemical analysis. The main tasks of chalking, drilling, and chemical analysis were as follows, and the problem was that they required a great deal of labor and time.
[Main work in each process] ・Chalking: Dimension measurement work/marking work ・Drilling: Drilling work/backfilling work ・Chemical analysis: Salinity concentration measurement work/report compilation work (Total time required for the above process: approximately 1 month (*)) *The larger the scale of the measurement target, the more effort and time will be required.
New technology: X-ray fluorescence analysis + augmented reality technology Developers: Tohoku University, Nihon University, Evident Corporation, Fukken Gijyutsu Consultants Co.,Ltd., XMAT Corporation NETIS registration number:TH-220006 *NETIS: New Technology Information System of “Ministry of Land, Infrastructure, Transport and Tourism”, Japan
As mentioned above, the technology developed by our group is to allocate coordinates to the concrete surface to be measured before measuring the concrete salinity concentration, and by simply pasting the reference position coordinate marker on the concrete surface, wearable glasses ( Position coordinates can be projected from Microsoft HoloLens 2), eliminating the need for traditional chalking work. Then, based on the projected position coordinates, the salinity concentration is measured using a handheld fluorescent X-ray analyzer (Evident VANTA). This operation takes approximately 30 seconds to measure each point, and since the measurement data can be handled electronically on the spot, the work process can be significantly shortened. By uploading the measurement data to the salinity visualization system (XMAT InfraScope), the salinity measurement data is synchronized on the wearable glasses, and the measured salinity values are output as a heat map, allowing you to identify areas with high salinity at a glance. *When the QR code indicating the reference coordinates (x,y)=(0,0) is detected by the camera on the wearable glasses, the map with the coordinates automatically assigned will be displayed as a hologram.
New technology application example
The above image is a demonstration displaying the salt concentration measurement data of the concrete deck of a highway bridge. A laser pointer indicates the measurement location on the map projected on the wearable glasses, and a handheld X-ray fluorescence analyzer measures the salinity concentration at that location. The results are then projected as a heat map on the wearable glasses. . *The size of the map cells can be specified arbitrarily. (The cell size of the image is 50cm)
Report creation support function
As shown in the image above, by using an application (XMAT InfraScope) implemented on Microsoft Excel, you can instantly create a heat map image file to attach to a report, simplifying the report creation process. It will be possible. Therefore, the chalking work, drilling/backfilling work, and chemical analysis work that were performed with conventional technology are no longer necessary, and concrete salinity measurement can be significantly simplified. *Currently, the InfraScope app is for salt damage diagnosis, but we plan to support other investigations in the future.
[Reference] Comparison of new technology and conventional technology
Concrete salinity investigation, which requires a huge amount of time and analysis costs using conventional methods, is now dramatically more efficient in terms of time, work, and cost using fluorescent X-ray analysis. Even during the repair work phase, by mapping survey data onto wearable glasses, it becomes possible to perform repairs while directly viewing concrete deterioration information, eliminating the hassle of copying inspection results and repair areas onto paper, etc., resulting in significant savings. Contributes to human labor.
In the maintenance and management of concrete structures, salt damage and deterioration due to salt air blown by the sea and the spraying of snow melting agents such as calcium chloride are becoming more serious. It is important to understand the amount of chloride ions in concrete in order to predict the progress of corrosion of reinforcing steel due to salt damage and consider repair methods. Generally, chloride ions are determined using potentiometric titration, spectrophotometry, silver nitrate titration, or ion chromatography. With these methods, it is possible to analyze the amount of chloride ions with high accuracy, but it is necessary to take the concrete core samples and powder samples collected from the site back to the laboratory, and the analysis time is approximately one month. On this point, VANTA can take measurements in about 30 seconds per point, making it possible to measure salinity at many points at once, making it extremely suitable for grasping trends in salinity in survey areas. Additionally, by combining VANTA with our visualization application (XMAT InfraScope), it is possible to create a salinity map of the surveyed area on the same day that salinity is measured.