The collapse happened at Eindhoven Airport on 27 May 2017. Dutch organisation for applied scientific research TNO, on behalf of Eindhoven Airport, and engineering consultant Hageman, assigned by BAM, have carried out the investigation into the technical cause of the collapse.
The parking structure was constructed using BubbleDeck floors, which consist of precast concrete floor slabs and are equipped with weight-saving plastic bulbs. After installation on site, a concrete topping was applied.
The investigations show that the shear strength of the interface between the precast concrete floor slabs was insufficient. As a result, the structural capacity of the floor was compromised. The high ambient temperature on the day of the collapse was a contributing circumstance to the defect manifesting itself.
BAM has shared the conclusions of Hageman's research with Eindhoven Airport and the Dutch Safety Board (Onderzoeksraad voor Veiligheid), as well as with the wider construction industry.
Further discussion among all parties involved will have to determine what will happen to the building and who can be held responsible for the incident.
Jaap Hazeleger, director of BAM Bouw en Techniek: “Fortunately an event like this is highly exceptional. We are very grateful that no personal accidents have occurred. With the investigation results in hand, we will engage in further talks with Eindhoven Airport to determine the most appropriate follow-up steps.”