ABSTRACT
The present study examines two related topics: the results of a pair of inter-laboratory studies
1 INTRODUCTION
The ASTM C1550 round panel test, shown in Figure 1 (ASTM, 2008) was first developed in the late 1990s as an alternative to the EFNARC panel test (Roux et al., 1989; EFNARC, 1996), which is now known as the EN 14488 Part 5 square panel test (EN, 2006). Several aspects of fibre reinforced shotcrete (FRS) performance as revealed using the ASTM C1550 test method were first published by Bernard (2000). Later work compared the repeatability of test data using this method with that obtained using beams and EFNARC panels (Bernard, 2002). Additional studies have since examined other aspects of the use of round panels for quality control (QC) assessment in the field (Hanke et al. 2002) and possible sources of error in this test method (Bernard & Pircher, 2001; Bernard, 2005; Bernard & Xu, 2008). As a result, the ASTM C1550 round panel test is a relatively well understood test method and results obtained using this test are specified in guides on the use of shotcrete (ACI, 2008; CIA, 2008).
