Shotcrete-Technology ´06

Wienerwaldtunnel - production wet-mix sprayed concrete in the MIC-System

Dipl.-Ing. Andreas Rath, Porr Technobau und Umwelt AG, Wien
Dipl.-Ing. Dr. Johannes Horvath, ARGE Bautech, Wien

The eastern section of the “Wienerwald–Tunnel” with its length of 13.35 km is build conventionally with the New Austrian Tunnel Method (NATM). The primary support was done traditionally by shotcrete according to the guideline - Sprayed Concrete – of the Austrian Concrete Society. During tunnelling about 75.000 m³ shotcrete have to be produced within three years. For the mixing of the sprayed concrete, a MIC-System (mixed-in-car) was installed in the tunnel. Charging of the containers for the aggregates and the binder is done from ground level. To guarantee an uniform aggregate distribution in spite of the greater high of fall, a special procedure had to be developed. Furthermore an adaptation of the truck-mixers had to be done to obtain a better quality of the shotcrete. The maximum length of concrete delivery was about 200 m. This report gives an overview of the necessary arrangements to guarantee an efficient and economical handling of the shotcrete process on this site.