Overview
ISO 12580:2007 - "Timber structures - Glued laminated timber - Methods of test for glue-line delamination" specifies five laboratory test methods (Methods A, B, C, D and E) used for factory quality assurance of the glue lines in glued laminated timber (glulam). The standard defines specimen preparation, required apparatus (pressure vessel, boiling/cooling baths, drying duct), detailed test cycles, measurement rules and reporting requirements to determine glue-line delamination under controlled moisture and temperature gradients.
Key topics and technical requirements
- Scope: Five delamination methods for factory quality assurance of glulam glue lines; intended to be used with ISO 12578 for production conformity.
- Specimen preparation: Test pieces taken from a full glulam cross-section, cut perpendicular to the grain, typically 75 ± 5 mm long. Splitting rules apply when cross-section width or depth exceed specified limits.
- Apparatus:
- Pressure vessel (safe for at least 600 kPa gauge pressure and 85 kPa gauge vacuum) for Methods A, B, C.
- Boiling and cooling vessels for Method D.
- Drying duct able to circulate air at 2–3 m/s and deliver the temperatures and relative humidities specified for each method.
- Test cycles:
- Methods A–C use vacuum/pressure water impregnation followed by controlled drying (different vacuum/pressure durations and drying climates).
- Method D uses boiling immersion followed by cooling and drying.
- Method E uses 24 h immersion and drying; for conformity assessment Method E is effective only when used together with Method D.
- Measurement and evaluation:
- Measure open glue-line lengths on end-grain surfaces after the final drying period (within 1 h).
- Ignore delamination at knots and isolated delamination < 3 mm if > 5 mm from nearest delamination.
- Total delamination % = (total open glue-line length / total glue-line length) × 100.
- Maximum delamination % for a single glue line = (maximum open length / (2 × glue-line length)) × 100.
- Reporting: Test method, timber species, adhesive type, production date/time, delamination percentages before/after extra cycles and tester identification.
Applications and who uses it
- Glulam manufacturers - routine factory quality assurance and batch testing.
- Testing laboratories - perform standardized delamination tests for product certification.
- Structural engineers, architects, and specifiers - verify glue-line durability data used in design and procurement.
- Certification bodies and regulators - assess conformity with production and component requirements when used alongside ISO 12578.
Related standards
- ISO 12578 - Timber structures - Glued laminated timber - Component performance and production requirements (intended companion for frequency and pass/fail criteria).
Keywords: ISO 12580:2007, glued laminated timber, glulam, glue-line delamination, delamination test methods, quality assurance, timber structures.
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