Fire-resistant boards provide new Rottemer tunnel optimal protection

The construction of the new A16 Rotterdam, situated between the A13 and A16 along the north-eastern edge of Rotterdam, is making steady progress. In order to optimally fit the energy-neutral national highway into the landscape, the Rottemerentunnel, among other things, is being built. When completed, this 2,235-meter-long land tunnel will be half sunken in the Lage Bergse Bos. Promat, specializing in passive fire protection, is providing the structure with fire-resistant boards. Solutions that fully meet the statutory requirements for fire reaction and fire resistance.

In the event of a fire in buildings or tunnels, it is of the utmost importance that the load-bearing structural elements remain standing for a sufficiently long period of time. At the same time, with a view to business continuity, it is important to limit any damage as much as possible. With the aim of making steel and concrete (supporting) structures fire-resistant, Promat, as part of the Belgian family company Etex Group, has been offering a varied range of fire-resistant products and systems for tunnels for more than 43 years. Self-developed quality solutions that provide the desired security in case of calamities, protect structures and guarantee safe passage in case of fire. By providing expert advice and testing structures, the company completes the toolbox for fire-safe construction. 

Sheet metal as customization

So too in the case of the Rottemer Tunnel, consisting of two tunnel tubes and a middle channel, a project being carried out by construction consortium De Groene Boog. "Most of the construction work involves a land tunnel that, according to the Rijkswaterstaat fire curve in accordance with regulations, has to be 60 and 120 minutes fire resistant," says Frank van der Wal, acting on behalf of Promat as Regional Tunnel Manager for the Netherlands, the Nordic countries and the United Kingdom. "That fire curve goes up to a temperature of 1,350 degrees Celsius. So in this case you cannot suffice with any fire-resistant product. That's why we opted for the tunnel slabs of type Promatect^®-TF-X, a relatively new product that has the advantage that it can be produced in any length from 2 to 3 meters, resulting in little sawing loss. Customization in optima forma, in other words. In addition, it is a passive system, so it does not need to be activated. You mount the plates and the tunnel is protected. It couldn't be easier. Furthermore, like our other tunnel slab products, this slab variant is optimally resistant to the influences of road salt, frost, thaw and dynamic loading." Promatect^®-TF-X is rated X according to EN-12467 (untreated to be used in outdoor situations).

Thicker layer

For the Rottemer Tunnel, Promat is supplying as much as 107,000 m² Promatect^®-TF-X. Meanwhile, the ceiling of the tunnel is completely covered with the effective sheet material. Once the tunnel technical installations (including lighting, cameras and loudspeakers) have been assembled and tested, the tunnel walls will follow. A job that De Groene Boog expects to complete around November of this year. A job also for which most of the fire-resistant sheet material will be used, it turns out. "The tunnel also goes under the Bleiswijkse Vaart and the peat river the Rotte," Van der Wal explains. "Because tunnels under water must legally comply with an RWS curve of 120 minutes, a thicker layer of sheet material was used here. This prevents the concrete from splashing and the tunnel tube from collapsing in the event of a fire."