Efectis Nederland remains actively involved in assessing the structural behaviour of tunnels; in this newsletter we put the spotlight on two Dutch tunnel projects.

In-situ fire resistance tests have been performed with the Efectis mobile fire resistance furnace MobiFire in the 2nd Coen Tunnel in Amsterdam. The fire tests were performed on concrete with a PP fibre addition, using the Rijkswaterstaat temperature/time fire curve. To prevent irreversible damage, it is critical for the concrete to be able to keep the temperature of the first reinforcement layer below a certain threshold value (for Rijkswaterstaat, below 250 °C). However, it is difficult to reliably measure the temperature of concrete in an existing tunnel and therefore a novel method of installing temperature sensors was developed by Efectis in the lab and applied in the tunnel. With the new method, Efectis can assess the structure against the set criteria.

Laboratory fire resistance tests have been performed for the Victory Boogie Woogie Tunnel near The Hague. The tunnel is named after a painting by the Dutch artist Piet Mondriaan and is one of Europe’s most sustainable tunnels.

The fire tests concentrated on the in-situ parts of the tunnel (entrance and exit). Stresses in the concrete were simulated using the Efectis external loading frame and the structure was heated in accordance with the Rijkswaterstaat temperature/time fire curve. Since the concrete did not have sufficient inherent fire resistance, a fire-resistant board system was used to protect the concrete. During the test campaign the fire-resistant board system was optimised and this improved system has been applied in the tunnel.

Last September, Efectis issued the new version of the procedure –written jointly with Rijkswaterstaat – for the testing of concrete tunnel lining:
Efectis-R0695:2020 Fire testing procedure for concrete tunnel linings and other tunnel components.
Link to the procedure: Efectis-R0695:2020.

Contact: Jos Bienefelt – jos.bienefelt@efectis.com