抄録
More efficient use of construction adhesives as structural fasteners requires detailed knowledge on the behavior of adhesive joints between load-bearing building components under actual service conditions. As the strength of adhesive joint depends on the shear strength of wood as well as the strengths of adhesive and its bonded surfaces, both the strength of adhesive joint and the percentage of wood failure are provided as the test indicators. In this report, the relationship between the shear strength of adhesive joint and the percentage of wood failure was derived from the strength of wood and adhesive. The proposed schematic representation showing the distributions, of shear strength and of wood failure can be a powerful tool for evaluating how the strength changes with time or under accelerated aging, or which of the degrading factors is the major one. Based on observation of the shear test and the appearance of the fractured adhesive, interpretation of the results and recognition of the estimates under aging will become easier. A recent inspection of adhesive joints for glue-laminated timber after 6 years outdoor exposures shows that the rate of change in joint strength is attributable to the wood degradation and no adhesive failure occurs.
