A professor at the Brussels School of Engineering, Arnaud Deraemaeker is a researcher in the BATir unit (Building Architecture & Town Planning). His research interests are structure dynamics, vibration dampening, and monitoring structure condition based in dynamic measurements. Among other activities, he supervises spin-off project TweetCon, which is supported by the Brussels-Capital Region and aims to develop a fully automated diagnostic kit for concrete structures.
August 2018 - A bridge collapses in Genoa
Arnaud Deraemaeker, BATir – Building, Architecture & Town Planning
Last August, the Morandi bridge in Genoa collapsed. What did this disaster teach us, Arnaud Deraemaeker?
The event revealed a very real problem in the upkeep of concrete structures, a topic that has been talked about for a few years without much being done. Most concrete bridges were built in the 60s and 70s, with an estimated lifespan of 50 years: this means we are now reaching a critical point in time. The problem is all the more significant that loads and vehicle numbers have both increased over the past few years.
In Belgium, following the disaster in Genoa, some forty bridges have been reported as critical. Should we fear a similar collapse?
I cannot see into the future, but I do know that cracks, concrete decay, and even stability issues have been found on many bridges. This means that significant renovations must be done quickly, in order to ensure the safety of all those who use these infrastructures. Unfortunately, maintenance work is often done as part of short-term policies, and urgent work is more expensive when no maintenance was done during previous years. Maintenance also requires closing off bridges, which decreases mobility, as evidenced by the destruction of the Reyers viaduct in Brussels.
What might be a long-term solution to the critical condition of our bridges?
Predictive maintenance of concrete structures could be an adequate solution. This involves measuring decay over the years and predicting its evolution in order to develop an optimal maintenance schedule. Predictive maintenance can extend the lifespan of a structure while keeping costs low, by taking appropriate measures as soon as an issue is detected and before it becomes critical.
Concrete structures are currently maintained by people who look for various signs of decay. Could monitoring be improved using technology?
There currently exist many types of sensors that can be embedded into civil engineering structures such as bridges, in order to monitor their condition, but there is also a dire shortage of algorithms that can interpret the data gathered. Therefore, the current priority is to develop a smart system that can analyse this monitoring data. This is why I am developing, together with my team, project TweetCon, with a goal to offer connected sensors in 1 to 2 years. These will be embedded directly into the concrete and send out information in real time about the structure's condition. Data will be collected and sent to an online portal, including information on cracks, humidity, and so on. There have been changes recently in how maintenance is done, with construction managers tending to place contractors in charge of the maintenance, which is now included in calls for tenders. As a result, contractors are looking closely at smart maintenance techniques using sensors, in order to reduce costs and gain a competitive edge.
Tuesday, August 14
In Genoa, Italy, the viaduct on the A10 motorway collapses. A 600-foot section of the concrete structure crashes onto a residential neighbourhood, taking motorists with it. Many are wounded, and 43 are dead.