Fires in tunnels are a major hazard to human life and can cause costly damage to the infrastructure. The limited escape exits and the difficulties encountered by intervention forces in gaining access call for extensive safety arrangements which must be complementary and mutually coordinated.
PROMATECT®-T boards at the Porte des Lilas
Promat manufactures and markets passive fire protection panels for tunnels. The Promat tunnel fire protection boards combine a lot of advantages, such as resistance to hydrocarbon combustion pollutions, resistance to humidity, resistance to steam diffusion, high performance, resistance to frost and de-icing salt, resistance to mould growth, etc. Its tunnel fire protection boards are mainly fabricated in Kapelle-op-den-Bos and Tisselt, Belgium and in Glasgow and Blackburn, UK.
At the Porte des Lilas in Paris, life improvement consisted in placing underground a section of the ring road, eliminatinf a noisy, visual barrier and redeveloping the area. The objectives of this large scale operation are multiple: favouring the transverse displacements between Paris and neighbouring municipalities of Pré Saint-Gervais, Les Lilas and Bagnolet; laying covering slabs and creating green spaces; implementing diversified programmes to foster social mixing and jobs.
Commenced in September 2005, the project consisted in building a sound-proof cover and nine escape exits, roadworks, and making safe the tunnels. Several types of risks have to be prevented in tunnels: risk for the lives of people and huge material damages. This is the assignment of Promat at the Porte des Lilas. The project was not an easy task because works had to be done without traffic disruption. This obliged to choose techniques easy and quick to implement, respectful of the environment thanks to the placement of a finished product, not sprayed.
Although a massive and incombustible concrete construction seems immune to fire, the resistance of a concrete structure is halved after a temperature increase of 500°C. Concrete is vulnerable to the spalling effect. Spalling can be described as the breaking of layers or pieces of concrete from the surface of a structural element when it is exposed to the high and rapidly rising temperatures experienced in fires. Explosive spalling is caused by the build-up of water vapour pressure in concrete during fire. If the concrete is not very permeable, water vapour formed within it during heating will not be able to dissipate and pressure is formed. When that pressure exceeds the tensile strength of the concrete, explosive spalling will result. Concrete pieces explode leading to the collapse of the structure.
Before and after at the Porte des Lilas in Paris
The ceilings need to be protected by fireproof boards to avoid such damage and the walls are also frequently protected. This is why Promat's PROMATECT®-T solution has been chosen for the Porte des Lilas. 25,000 square metres of 20 mm PROMATECT®-T boards have been installed on the ceiling on two sections of 317 and 362 metres. Work took place sometimes at night but the ceiling height, which is never the same, always obliged to adjust the lifting platform. Read
E-News Weekly 16/2006.
PROMATECT®-T boards are capable to protect all the safety systems for two hours during a violent fire. PROMATECT®-T is a highly insulating non-combustible autoclaved calcium silicate board specially designed for the protection of concrete and steel in tunnels and underground structures.
The PROMATECT®-T thermal insulator can be installed in a tunnel under construction or an existing tunnel. Although designed as panels, the engineered matrix allows to curve a board on site to cover surfaces with a diameter of curvature down to eight metres. Easy to install by clean techniques, the application of the engineered matrix products can be performed on existing tunnels without total interruption of the traffic.
The board is off-white with a smooth face and the opposite face slightly textured. The PROMATECT®-T boards can be applied to withstand temperatures of up to 1,350°C. They are resistant to moisture and humidity, corrosion, frost and thaw. An accelerated ageing method, which consisted of 100 24-hour cycles of heating, rain, frost and thaw, showed that the panel did not deteriorate and kept its properties and mechanical performance as well as its consistency.
PROMATECT®-T boards were used for fire protection in the Runehamar test tunnel in Norway during four successive fire tests performed in the frame of the European UPTUN project. Visit
www.uptun.netHistorically, passive fire protection in tunnels started in France after the Mont Blanc tunnel disaster. An official circular (# 2000-63 of 25th August, 2000) on fire safety in tunnels was prepared by the Centre d'Etudes des Tunnels (CETU). It applies to tunnels longer than 300 metres and defines the measures to reduce the likelihood of a fire, detect abnormal situations and ensure communication with users, make possible the protection and rescue of users and the access for rescuers, and protect oneself and fight a fire. To date, more than 100 tunnels have been protected by Promat. PROMATECT®-T boards have been installed in 16 tunnels in France: Toulon (20,000 sq m), Frejus (25,000 sq m), Fourvière in Lyon and Chamoise in the Alps. Visit
www.promat.fr,
www.promat-tunnel.com and
www.paris.fr/portail/deplacements/Portal.lut?page_id=5934 
