Rolph Segers, MSc
- Technology Transfer
- Corporate Venturing
Contact Tech Transfer
Brick-built constructions can develop cracks for a variety of reasons, and in the worst cases it can involve the risk of collapse. Manual inspections are time-consuming, expensive, and not always dependable. TNO has developed an automated method of detecting cracks in brickwork which makes such inspections simple, cheap and reliable. Cracks can arise as the result of ageing, dryness, vibration caused by heavy traffic, building work, and earthquakes. These cracks can make houses uninhabitable, make quay walls and chimneys unreliable, and make historic buildings vulnerable. In many cases cracks are not discovered until very late.
TNO has developed algorithms that allow photographs to be used to detect cracks, to identify whether they are expanding, and if so by how much. This makes it possible to intervene at an early stage to avoid dangers. The method was extensively tested in 2018, using the vibrating table that was installed at BuildinG in Groningen in early 2018. Its principal purpose was to simulate vibrations for research into the consequences of earthquakes for gas extraction, but it is also the ideal tool for testing a crack detector. TNO experts made many hundreds of photographs during these tests, and assessed them with software they themselves developed.
More than a thousand masonry objects have been photographed, such as houses, churches and quay walls. Inspectors photographed these objects according to a work instruction from TNO, so that good quality photos were obtained. Only then can cracks in the masonry be automatically detected objectively, quickly and reliably.
Currently there is a lot of interest from companies and organizations responsible for such inspections. The model combines the photos into a single facade or quay wall and scans them for cracks. If cracks are detected, the position, width and length are determined. With multiple exposures in time, it is therefore also possible to determine growth. This is not only important from a structural point of view to be able to guarantee safety, but also prevents discussions afterwards about the cause of damage. This model is expected to be operational in early 2021.