Application and testing of plastic fibre reinforced dry-mix shotcrete / Einsatz und Prüfung von kunststofffaserbewehrtem Trockenspritzbeton

The Conrad Observatory in the state of Lower Austria is a geophysical research and development facility of the Central Institute for Meteorology and Geodynamics (ZAMG). The isolation of the tunnel system fulfils the optimal requirements for high-precision measurements. The client specified shotcrete class EV700 for the plastic fibre-reinforced shotcrete, i.e. the test bodies have to show an energy absorption capacity of at least 700 J in the slab test. The quality verification for the suitability of a fibre-reinforced shotcrete is performed according to the ÖVBB guideline "Sprayed Concrete" with a slab test as defined in the Austrian standard ÖNORM EN 14488-5, which can determine the energy absorption capacity and assign the shotcrete to an energy absorption class. The test rig used at the Chair of Subsurface Engineering is described, together with test results from different plastic fibre shotcretes from various testing institutes.