June 7-10, 2009
The Western Australian School of Mines (WASM) has developed a facility for the static testing of full scale ground support elements. The test facility consists of several stiff steel frames used to support the sample and a screw feed jack is used to load the sample. A large scale punch test method has been developed to evaluate various shotcrete mix designs at different curing times. The shotcrete is sprayed on to a sandstone substrate containing an isolated disc that is centrally located. The test sample is placed on to the sample frame and restrained on all sides. The disc is displaced at a constant rate by the screw feed jack which in turn loads the sample. Instruments measure the displacement and the load being applied to the sample through the loading disc. The test method has been used to compare the force – displacement properties of different mix designs and reinforcing materials including plastic fibres, steel fibres and mesh. The force – displacement properties have been used to determine the energy absorbing capability of fibrecrete systems.
Ellen C. Morton, Ernesto Villaescusa, and Alan G. Thompson, "DETERMINATION OF ENERGY ABSORPTION CAPABILITIES OF LARGE SCALE SHOTCRETE PANELS" in "Shotcrete for Underground Support XI", Felix Amberg, M.o.S. ETHZ, SIA, Switzerland; Knut F Garshol, BASF Construction Chemicals, LLF, USA Eds, ECI Symposium Series, (2009). http://dc.engconfintl.org/shotcrete/7