The design of fibre reinforced shotcrete (FRS) linings for tunnels or mines is commonly based on the well-known and widely recognised Q-System or Barton charts. This performance based design approach accesses the results of experimental tests, carried out on panel specimens according to existing standards or guidelines. This is different to the general methodology to access and determine the performance of fibre reinforced concrete (FRC) using standardised beam tests. Panel and beam test results yield significantly different information on the performance of FRC and it is problematic to correlate them. The beam test yields a stress-strain relationship for a small displacement range only. However, ground deformation and crack development can make it very difficult to predict exact stresses in a shotcrete lining. Performance data from panel tests at larger displacements are the safer option regarding the design. A beam test is a low deformation test (up to 4 mm central displacement) and thus, does not provide information for larger displacements that can be found in usual underground environments. Due to the geometry of the specimens and its test setup, a beam test focuses only on the small width of a singular crack with a very short crack length, depending on the specimen width. These limitations make it unrepresentative for statically indeterminate and highly redundant shotcrete linings, where stress redistribution is possible and larger deformations occur.
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