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LOCADIFF
A DISRUPTIVE INNOVATION FOR DURABLE MANAGEMENT OF CONCRETE INFRASTRUCTURES
To detect at a very early stage and pinpoint the point of damage of a concrete structure, Eric Larose has developed a monitoring technique using ultrasound combined with signal-processing software, the latter developed by Vincent Rossetto. An innovation that will become essential for civil engineering.» Description and functionalities
Monitoring of concrete structures through a non-destructive control using the ultrasound coda (diffuse wave). Based on the geometry of the structure in question and the ultrasonic waves recorded at different dates, the imaging software localizes the appearance of millimetric mechanical flaws (holes, damage, cracks…).- Signal processing to obtain a 2D or 3D map of the probabilities of flaw appearances with a resolution of several centimeters.
» Technology
- Ultrasonic transducters- Mesoscopic approach: diffuse waves (coda) analysed in phase and amplitude
- Data-processing software
» Performances
- Utilisation of diffuse ultrasounds.- Non-destructive method.
- Millimetric detection sensitivity with a spatial resolution of several centimeters.
- Efficient measurements on buildings made of aggregate concrete.
» Target
- Construction materials- Use, storage
» Application areas
- Civil Engineering- Seismic prospection and monitoring
- Radio and radar monitoring
» Laboratory
Laboratory of Internal Geophysics and Tectonics Tectonophysics. ref. 081016-Larose_Locadiff_ offre_05022010_FR1» Transfer offer
Industrial demonstrator» Interview with Eric Larose
What led you to begin working on this innovation?
For the past twenty years our lab has been working hard on the problem of wave diffusion and the localization of diffuse waves.
At the same time, for the past few years there has been a strong demand for concrete strucure imagery in civil engineering. Many structures are now worn out, such as bridges or nuclear plants. There is therefore a lot at stake to understand the causes of damage and ageing in concrete structures.
Monitoring techniques already exist, but today engineers need to be able to detect small flaws, and early enough so that these flaws do not turn into major cracks or fractures.
The most logical solution to this seemed to us to be the use of ultrasounds in the concrete. We are currently developing this for use in civil engineering.
How could a company use your innovation ?
Sensors are placed one meter apart on the structure under study to obtain a resolution of several centimeters, or placed closer together to obtain a more specific reading. We thus obtain ultrasonic prints of the concrete on several dates, and then compare them. This comparison allows us not only to detect any change but also to pinpoint it to within one centimeters. We've developed a laboratory prototype weighing 600 kg. We'll need to build a demonstrator on an industrial scale. Either we bring in our expertise and guidance, or we build this in conjunction with the Laboratoire central des Ponts et chaussée in Nantes.
What is your work environment?
Five people are working on this project in an interdisciplinary approach. Seismologists working with acousticians and opticians and thereby taking advantage of the progress made in related areas.
