ISO 9046:2021

Overview

ISO 9046:2021 - "Building and civil engineering sealants - Determination of adhesion/cohesion properties at constant temperature" specifies a laboratory test method for assessing the adhesion and cohesion behaviour of sealants with predominantly plastic behaviour used in buildings and civil engineering works. The standard describes specimen preparation, conditioning, cyclic extension/compression testing and reporting requirements to identify loss of adhesion or cohesive failure.

Key topics and technical requirements

• Scope: Applicable to sealants with predominantly plastic behaviour used in building and civil engineering applications.
• Specimen preparation
  • Two parallel substrates (mortar, anodized aluminium or glass per ISO 13640) with a sealant bead between them.
  • Spacers: 12 mm × 12 mm × 12.5 mm with anti‑adherent surface.
  • Anti‑adherent substrate examples: PE film, PTFE or microporous PTFE (manufacturer advice recommended).
  • Avoid air bubbles; press sealant to substrate faces and trim flush.
• Conditioning
  • Preconditioning: 28 days at (23 ± 2) °C and (50 ± 10) % RH.
  • Specific conditioning: 14 days in ventilated convection oven at (70 ± 2) °C, plus 1 day at (23 ± 2) °C and (50 ± 10) % RH.
  • A container for water immersion is specified for conditioning method B (where applicable).
• Test procedure
  • Cyclic extension/compression: 100 cycles at a speed of (1 ± 0.2) mm/min using a test machine.
  • Amplitude options: ±12.5% or ±7.5% (or other agreed amplitudes); initial specimen width = 12 mm (widths after cycling provided in the standard).
  • Allow specimens to relax for one hour after cycling, then inspect for loss of adhesion/cohesion.
• Measurement and reporting
  • Measuring device scaled to 0.5 mm for failure depth measurement.
  • Test report must include laboratory, sealant identification (type/chemical family, batch), substrates, primers, mixing proportions, cycling amplitude and the depth/location of adhesive/cohesive failures.
• Updates in 2021 edition: title modified; test machine rate, relative humidity requirement and anti‑adherent substrate recommendations revised.

Applications and users

• Who uses it: sealant manufacturers, independent test laboratories, quality control teams, product developers, specification writers, façade and civil engineering consultants.
• Practical uses:
  • Product development and comparative performance testing of sealants.
  • Quality control and batch verification.
  • Support for technical specifications and compliance claims in building and civil engineering projects.
  • Evaluating durability of sealant adhesion/cohesion after thermal conditioning.

Related standards

• ISO 6927 - Sealants - Vocabulary (terms and definitions)
• ISO 13640 - Sealant test substrates (mortar, anodized aluminium, glass)

Keywords: ISO 9046:2021, sealants, adhesion/cohesion, building sealants, test method, conditioning, extension/compression cycles, substrates, sealant testing.