The RABT tunnel fire curve

Area of application of the RABT curve

The "Guideline for the equipment and operation of road tunnels" (RABT) defines the so-called RABT tunnel fire curve in addition to other important points. This is often used for the fire protection design of tunnel structures. The temperatures as a function of time are shown in Fig. 1. Similar to the ISO standard fire for building construction, the RABT tunnel fire curve is an artificial fire room curve. It is intended to cover the maximum temperatures resulting from tunnel fires while remaining on the safe side. The curve can be used, for example, in a fire design for the tunnel.

Tunnel fires

Tunnel fires are particularly dangerous. If the fire load is sufficient, tunnels resemble a chimney, as there is usually very good ventilation (i.e. oxygen supply). Because very high fire loads, e.g. from trucks, often occur in the tunnel structures, very high temperatures can occur in tunnel fires. For this reason, increased fire protection requirements are placed on tunnels.