Applications - Tunnels

Not only is there a risk to human life but also severe damage to the tunnel structure can occur, requiring extensive repairs or even causing collapse of the tunnel. The resulting disruption of transport links can cause serious economic or social problems such as increased traffic congestion, reduction in tourism or damage to local businesses.

Many studies have shown that the fires generated in road tunnels burn at a very high temperatures. The EU “UPTUN” Project has demonstrated that a HGV carrying an 'ordinary' load can generate a fire comparable to that from an oil tanker with temperatures over 1300ºC recorded.

A number of fire curves have been developed to represent the temperatures generated in real fire situations. Of these the RWS curve developed in Holland is the most severe and is now widely used in fire tests developed for tunnel fire protection systems.

The need for fire protection in tunnels

High-strength concrete used in tunnel linings is vulnerable at high temperatures due to either explosive spalling or over-heating of steel reinforcement bars within the lining. Collapse of the tunnel can occur or at least extensive damage, requiring lengthy repairs.

Spalling can take place at temperatures as low as 200ºC.

Fire performance requirements

The safety of people in a tunnel during a fire is important and there is a need for fire proof refuges or escape routes. Cable trays, structural steel or fuel drainage systems all may need to be protected against fires. All these elements of the tunnel structure need an insulating fire resistant layer to provide thermal protection against temperatures above 1300ºC.

FireBarrier 135

FireBarrier 135 is a refractory cement fire protection material specially developed for the high temperatures developed in tunnel fires. It can be applied by spraying or cast into sheets.

FireBarrier 135 has many benefits

• Refractory Product - can withstand repeated exposure to 1350°C for long cycle times
• Very low spraying wastage during installation - less than 1% of weight
• Fast and easy to install - one, single layer application
• High adhesion strength - eight times greater than product weight
• High quality surface finish that can be painted

Resistant to real tunnel fire temperatures

Unlike most other products used for tunnel fire protection, FireBarrier 135 is a refractory material able to withstand repeated and prolonged exposure to high-temperature exposure. In fire tests, when exposed repeatedly at temperatures of 1350ºC FireBarrier has shown consistent performance as a protection to concrete.

Resistant to tunnel operating conditions

Extensive tests at the TNO laboratory have proven the resistance of FireBarrier 135 to environmental conditions found in tunnels. FireBarrier 135 is resistant to water jet sprays used to clean tunnel linings. FireBarrier 135 is will not spall when subjected to water hose sprays at high temperature providing safety for fire-fighting.

High quality surface finish

FireBarrier 135 can be trowelled flat to provide a high-quality surface finish that can be used as the final tunnel lining surface (with optional painting). This avoids the need for expensive secondary cladding.

High strength

FireBarrier 135 has high adhesion strength typically 8 times its weight, allowing fixings to be attached directly to it. Like concrete, strength increases over time. Adhesion has been verified in use and in independent laboratory tests.

Ease of installation

FireBarrier is easy to install with virtually no wastage due to spray re-bound. It is installed in one single layer with quick dry times.

It can be installed onto concrete or metal substrates using standard spray equipment (Putzmeister M11 or PFT G4/G5).

FireBarrier 135 is normally installed by spraying over a mesh, which is fixed to the concrete lining using “pig tail” anchors.

FireBarrier 135 is one of the most extensively fire-tested products available for tunnel fire protection with numerous tests to the various fire standards in force. Numerous tests have been carried out to the RWS and HCM high-temperature tunnel fires. In these tests FireBarrier is required to insulate the concrete substrate to below 380ºC and reinforcement bars inside to below 250ºC (25mm from the concrete surface). Some tests have even lower maximum temperatures allowed for the concrete as spalling temperatures vary for different concrete grades.

Versatility

FireBarrier 135 can also be cast into sheet form and installed as a dry board or shape for applications where spraying is not convenient.

Efficient

FireBarrier is an efficient insulation at high temperature with low thickness requirements to meet fire protection performance.

FireBarrier 135 - Versatility in fire protection of tunnels

There is a FireBarrier solution for every fire situation in a tunnel.

Project:	El-Azhar Tunnel (Cairo · Egypt)
Requirement:	Fire Protection of Main Concrete tunnel structure 2 hours RWS fire curve
Application:	Thickness Applied: 47mm in one single layer
Volume:	57000m2 of FireBarrier 135 applied (3442 Tonnes)
Project:	Mont Blanc Tunnel (France · Italy)
Requirement:	Fire Protection of Escape Refuges 2 hours HCM and 4 hours ISO fire curves
Application:	Thickness Applied: 42mm in one single layer onto Bioclima 30 bricks
Volume:	1700m2 of FireBarrier 135 applied (110 Tonnes)
Project:	Foix Tunnel (France)
Requirement:	Fire Protection of Tunnel Roof 2 hours HCM fire curve
Application:	Thickness Applied: 28 mm in one single layer
Volume:	21500m2 of FireBarrier 135 applied (800 tonnes)
Project:	L Epine Tunnel (France)
Requirement:	Fire Protection of fuel drainage system
Application:	Thickness applied : 75mm of FireBarrier 135 precast flat slabs
Requirement:	Fire Protection of Escape refuges, Ventillation Extract machinery, cable Penetrations. 2 hours HCM curve and 4 hours ISO 834 curve
Application:	Thickness Applied: 28 mm in one single layer
Volume:	100 tonnes FireBarrier 135 applied
Project:	Lecco Tunnel (Italy)
Requirement:	Fire Protection of Tunnel Roof, Ventilation ducts and Escape passages 2 hours HCM fire curve, 4 hours ISO curve
Application:	28 mm in one single layer for concrete exposed to HCM curve for 120 minutes. 12mm in one single layer for concrete exposed to ISO 834 curve for 2 hours. 35mm for steel sections exposed to HCM fire curve for 2 hours. 35mm for steel sections exposed to HCM fire curve for 2 hours
Volume:	40000m2 of FireBarrier 135 applied (1148 tonnes)
Project:	Verla Di Giovo Tunnel (Italy)
Requirement:	Fire Protection of steel bulkhead forming air ventillation shaft 2 hours Hydrocabon fire curve (1100 ºC)
Application:	Thickness Applied: 44mm average in one single layer (30mm to 58mm on corrugated steel bulkhead)
Volume:	5500m2 FireBarrier 135 installed (330 tonnes)