Rolph Segers, MSc
- Technology Transfer
- Corporate Venturing
For more information, 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.
Existing photographs of brickwork, for instance those provided by inspection services, have yet to be examined in this way. This will make clear what specifications such photographs must meet in order to be usable for this method. These specifications will concern distance from the brickwork, lighting, pixel density and so on. With photographs of adequate quality, brickwork cracks can be detected objectively, quickly, and reliably.
The services and organizations that are entrusted with such inspections have already shown great interest in this technology. Following the tests in the Groningen lab, TNO is preparing a Proof of Concept in which the software will assess many thousands of photographs to accurately establish the position, width, length, and when compared over time, growth of any cracks. This will be important not just from the point of view of building and construction safety guarantees; it will also help to prevent disputes after the fact in the event of damage. Those who stand to benefit from this product will include private owners, housing associations, property managers, insurers, construction companies, and governments, both in the Netherlands and abroad.