Shotcrete-Technology ´06

Special aggregates for shotcrete with highest fire security

Dipl.-Ing. Wolfgang Mörth, Dipl.-Ing. Christof Haberland, Dipl.-Ing. Dr. Johannes Horvath, A. Porr AG, Wien

On the basis of the increasing public road- and railway traffic and the increase of risks interconnected with it, the importance of structural fire protection in tunnel constructions is a main objective in many countries. The lining system of tunnels must be planned in a way that sufficient protection of life safety is guaranteed in the case of a fire on the one hand, and on the other hand the repair measures must be economically justified and the reconstruction of the tunnel must be performed as quickly as possible. In recent years intensively investigations concerning the use of special aggregates with reduced heat conductivity and increased thermal stability (constant volume and no modifications) were done. The reduction of the heat conductivity of this special shotcrete leads to lower concrete cover and as a result of the enhanced temperature resistance to minor repair costs after fire. This special sprayed concrete can be used for the improvement of the fire resistance of consisting tunnel linings or for the repair of damaged constructions after fire ingress.