Faq

  • How relevant are the temperature curves for a given tunnel?

    The temperature curve is very important. If the temperature curve selected exposes the material to a lower temperature than the temperature in the fire in reality, the protection material will be under-specified. The Eureka fire tunnel project has revealed temperatures of vehicular fires of up to 1300° C. Even if a lower fire exposure curve is specified, the protection material should have melting temperatures above the potential worse case temperature. 

  • How will the protection material react to alternating pressure from vehicular traffic?

    A test has been carried out in Germany’s iBMB subjecting PROMATECT® specimens to 110,000 cycles of alternating pressures; 3 times more than normally encountered in vehicular tunnels. No displacement of the board occurred.

  • Should the vertical tunnel walls be protected as well?

    In most cases, fire scenarios are such that also in the lower parts of the tunnel, high temperatures are to be expected, not much different from maximum temperatures near the ceiling, suggesting also protection of the vertical tunnel walls up to road or track level. This depends on the assessment of the risk by the relevant authorities and fire consultants. In many tunnels up to 1 metre of the wall down from the tunnel soffit requires fire protection.

  • What happens if after installation there are any gaps between the PROMATECT® H boards ?

    This depends on the size of the gaps. Panels have been tested where gaps of 5mm were deliberately left between the panels in an attempt to simulate poor installation, no adverse affects were recorded in these tests.

  • What is the experience of such repairs in other protected tunnels?

    The worst case scenario is the PROMATECT®-H panel has to be removed to allow access for the concrete repair. This is quite easily achieved.

  • Which is the best protection method that will minimise servicing requirements after the tunnel is completed - post cladding is easier to remove, while lost shuttering is more difficult?

    Promat have about 30 years of experience in detailing and providing fire protection systems to tunnel applications. To date there has not been a requirement to totally remove PROMATECT®-H boards for servicing. It is true that post cladding facilitates ease in retrieval. 

  • Does the length of tunnel influence the protection period required?

    The longer the tunnel, the higher the risk and the more serious the evacuation efforts, the risks and hazards compound themselves. 

  • Does the PROMATECT®-H protection inhibit the regular inspection and maintenance procedures of the tunnel, especially for water seepage and concrete spalling?

    Water seepage is expected especially in the sub-sea tunnels such as those in the Netherlands. For example, Westerschelde tunnel has a 12m water column. PROMATECT®-H can be soaked by the water seepage but the board is unaffected by water. Wet spots are therefore visible and hence do not inhibit inspection.  

  • How about reinforcment bar carbonisation? How would a PROMATECT®-H lining affect the treatment of this problem in tunnels

    The concrete cover should be designed for addressing this aspect, although the PROMATECT®-H lining shields the concrete from direct contact of aggressive car pollution. An examination of the 9 year old PROMATECT®-H board cladding to Velser tunnel in Netherlands was conducted. The PROMATECT®-H showed negligible lost in strength and the no rebar carbonisation was visible in the concrete.

  • How are cracks in the concrete during fixing of protection material treated?

    Cracks in the concrete pose no problem to the PROMATECT®-H boards. If cracks in the concrete need to be repaired, the boards can be removed, or drilled through to gain access to the concrete for grouting repairs.

  • How do we build in maintenance and service procedure for PROMATECT® after the protected tunnel is operational?

    PROMATECT® boards need no maintenance. 

  • How do we ensure the screws or bolts remain in situ ?

    If the PROMATECT®-H is used as permanent shuttering the screws are embedded within the concrete, thus they cannot fall out, if the bolts used for fixing using the post installation method described in section 8.2, are not tight, the board will fall as the support is removed.. Tests have been carried out to show that even without the screws, a section of board used as shuttering has a very high adhesion to the concrete and will not fall away, tests on fully soaked boards have been carried out to simulate the effects on suction and to ascertain whether the bolt heads and washers would pull through the board. These tests were carried out on 15mm, 20mm, 25mm, and 30mm and showed that very high loads are required to pull the fixings through the boards. The average pull through strength measured for a 25mm board, fully immersed in water for 72 hours prior to the test, was a pull through load of 1884N for a 6mm diameter expansion bolt, and 1271N for a 5mm diameter screw.

  • How does the fixing of services and lighting to a protected concrete soffit affect the fire performance of the concrete ?

    Drilling through the panels does not adversely affect the performance of the system, assuming of course that the installer does not go to far and drills holes everywhere. Tests have been carried out to both RWS and Hydrocarbon curves where services have been bolted through the PROMATECT®-H ( simulated in the tests by suspending weights from expansion bolts ) and the performance of the system is consistent between these tests and the standard tests where no penetrations have been made. Of course, all services should be supported directly from the concrete and the installer should not rely on fixing any services only to the PROMATECT®-H boards

  • How is the tunnel structure fire protection material installed?

    PROMATECT® boards has been installed as lost shuttering and as a post cladding material.