A round robin study using the CSA O112.9-10 standard was conducted with three (3) participating test laboratories in Canada as recommended by the Standards Council of Canada (SCC). The study included only the block shear test under three test conditions (dry, vacuum-pressure, and 9-cycle boil-dry-freeze). Test specimens were prepared using black spruce as substrate and phenol-resorcinol formaldehyde adhesive as the bonding agent.
All participating test laboratories passed the shear test of the CSA O112.9-10 standard in which the requirements are based on quantile parameters (median shear strength, median and lower quartile wood failure). This finding showed that the block shear test method of this adhesive standard was reproducible among three well-known test laboratories in Canada, all of which have been qualified by the SCC for the ISO 17025 accreditation program.
The test laboratories, however, exhibited some differences in terms of average shear strength and wood failure in the three test conditions. Some possible reasons were suggested for these differences.