Every summer, the same scenario repeats itself: cracks appear on façades, houses become deformed, and roads lift. The cause? The phenomenon of Shrink-Swell of Clays (SSC), exacerbated by drought.
This silent scourge affects a large part of French territory, and incidents related to RGA are increasing year by year. In the face of this challenge, a new generation of solutions is emerging: connected structural monitoring sensors.
RGA: an invisible but formidable phenomenon
The RGA results from variations in water content in clay soils. When it is dry, these soils contract; when they are rehydrated, they swell. The result: differential movements under the foundations, leading to cracking, disorder, and weakening of structures.
With the intensification of drought episodes, the phenomenon is accelerating. According to the MRN, more than 10 million individual houses are now located in at-risk areas. However, proactive monitoring remains rare, often limited to occasional or visual inspections.
When does a crack become dangerous?
It is crucial to distinguish the types of cracks in order to assess their severity:
- Microfissures: Less than 0.2 mm, they are generally superficial and pose no immediate danger.
- Fine fissures: Between 0.2 and 2 mm wide, they can be benign but require monitoring if they change or multiply.
- Deep and dangerous cracks: Beyond 2 mm in width and 20 cm in length, they are concerning, especially if they are through cracks (visible on the inside and outside). These cracks may indicate serious structural problems and should be assessed by an expert.
Connected sensors: continuous monitoring to anticipate risks
This is where technology comes into play. Thanks to connected sensors like those developed by Feelbat, it becomes possible to monitor in real time and remotely the evolution of cracks and ground movements.
Example: the DELTA L+ mini, an ultra-compact crack sensor, capable of detecting changes on the order of a tenth of a millimetre. Easy to install, it automatically transmits its data via a mobile application.
Data combination: Ground movements directly affect cracks. It is therefore essential to understand this interaction. By combining data from crack sensors with that from ground movement sensors, a comprehensive and accurate view of the structural health of the building is obtained.
Results :
- Continuous monitoring of deformations.
- Automatic alerts as soon as a critical threshold is crossed.
- Reduction of intervention and travel costs.
Concrete applications in the field
The sensors are already used in areas classified as natural disaster drought zones. They allow for:
- Monitoring the progress of a claim, to support a compensation file.
- Prevention of structural disorders upstream.
- Better planning of underpinning works.
Some local authorities even integrate these sensors into their heritage management strategies, in order to monitor the impact of droughts on public buildings or sensitive roadways.
Example: The town of Auriol has installed Feelbat sensors to monitor the cracks that have appeared on certain municipal buildings, allowing for quick and targeted intervention.
Key data to act, not to suffer
One of the great contributions of technology is the availability of objective data, accessible from anywhere. Thanks to the Feelbat application, research offices, judicial experts, surveyors, or local authorities can:
- Consult the history of measurements.
- Export the data for detailed reports.
- Identify the areas of active development.
This approach transforms RGA risk management: we no longer endure, we understand and we anticipate.
A solution tailored to all stakeholders in the sector
Whether in initial diagnosis, post-incident monitoring, or within the framework of a public contract, Feelbat's connected sensors adapt:
- To the experts to document the developments.
- To local authorities to monitor their assets.
- To construction companies to enhance site safety.
- To the affected homeowners to support their claims with the insurance companies.
A solution tailored to all stakeholders in the sector
With climate change, episodes of drought will intensify. The Shrink-Swell of Clays is no longer a marginal risk: it is a central challenge for the building and geotechnical sector.
But with the right tools, such as Feelbat's connected sensors, it becomes possible to regain control, act at the right moment, and sustainably preserve structures and people.
Press Contacts:
Impulse Communication Agency Paris
Marie Legrand – marie@impulse-communication.fr – 06 09 88 62 27
Julie Dalsace – julie@impulse-communication.fr – 06 78 70 96 05