ISO 19861:2015

Overview - ISO 19861:2015 (Determination of curing behaviour of sealants)

ISO 19861:2015 specifies a laboratory method for determining the curing behaviour of sealants used in joints in building and civil engineering works. The standard defines procedures for both one‑part (single component) and multi‑component sealants, describing specimen preparation, conditioning, testing intervals, measurement methods and reporting requirements. Conditioning is carried out at (23 ± 2) °C and (50 ± 10) % RH to ensure repeatability of results.

Key topics and technical requirements

• Scope: Test method for curing behaviour of sealants in building construction joints.
• Specimen types:
  • One‑part sealants: 15 specimens in plastic or metal cylindrical cups (35–75 mm internal diameter, 35–50 mm deep, wall thickness 1–3 mm).
  • Multi‑component sealants: drawn down slab ≥ 6 mm thickness, 50 mm × 300 mm.
• Conditioning: All specimens brought to (23 ± 2) °C over 24 h and cured at (23 ± 2) °C / (50 ± 10) % RH.
• Test procedure:
  • One‑part: remove cured skin on three cups at intervals (16 h, 24 h, 48 h, 72 h, 96 h, 168 h) and measure cure depth; time to 2 mm cure in depth determined by linear interpolation of averaged data.
  • Multi‑component: hardness testing per ISO 868 (Shore A/00); measure before and around manufacturer recommended cure time and until hardness reaches 33% of ultimate (28 day) hardness; time to 33% determined by linear interpolation.
• Instrumentation: scaled measuring device (0.5 mm) for depth; Shore durometer capable of A scale (or 00 for extremely soft materials).
• Reporting: laboratory ID, test date/number, reference to ISO 19861, sealant name/type/colour/batch, one‑part cure depths at specified intervals and time to 2 mm, multi‑component hardness readings and time to 33% ultimate, any deviations.

Applications and who uses ISO 19861:2015

• Sealant manufacturers - validate cure performance claims, support technical data sheets and R&D.
• Independent test laboratories - provide standardized cure characterisation for product certification and quality control.
• Specifiers, architects and engineers - assess suitability of sealants for joint design and installation schedules.
• Contractors and quality assurance teams - verify on‑site product behaviour against laboratory expectations.

Practical benefits include predictable joint performance, informed material selection, and documented cure times to support construction scheduling and warranty claims.

Related standards

• ISO 868 - Plastics and ebonite - Determination of indentation hardness (Shore hardness)
• ISO 6927 - Sealants - Vocabulary

Keywords: ISO 19861:2015, curing behaviour, sealants, cure in depth, Shore hardness, sealant testing, one‑part sealant, multi‑component sealant, building construction.