Overview
ISO 24070-2:2021 - "Building and civil engineering sealants - Determination of cured thickness of one‑component sealant - Part 2: Cylindrical cup test method" specifies a laboratory method to measure the cured thickness of one‑component sealants using a cylindrical cup. The standard defines specimen preparation, conditioning, test procedure, measurement and reporting requirements to produce reproducible cured‑thickness data for quality control, product development and specification compliance.
Key topics and technical requirements
- Test principle: fill an anti‑adherent cylindrical cup with sealant, tool flush, cure under specified conditions, remove cured disk and measure thickness at the centre.
- Cylindrical cup dimensions: inner diameter 35–75 mm; depth (along wall) 35–50 mm; wall thickness 1–3 mm. (Disposable HDPE/PP cartridge plungers are commonly used.)
- Tooling and measurement tools: scraper (width ≥ cup diameter + 20 mm) to level the sealant; thickness calliper with reading accuracy of 0.1 mm.
- Conditioning: cups and sealant conditioned for a minimum of 16 h at (23 ± 2) °C and (50 ± 10) % RH.
- Specimens: prepare three specimens per cure duration (e.g., 8 h, 24 h, 48 h, 72 h, 96 h, 168 h).
- Curing and testing climate: standard conditions (23 ± 2) °C and (50 ± 10) % RH) unless otherwise agreed; note that ventilation and proximity to other curing sealants can affect cure rate.
- Result expression: report cured thickness in millimetres at the centre of the cured disk. For time to reach 2.00 mm cured thickness, determine via linear interpolation between adjacent data points.
- Test report items: laboratory name/date, reference to ISO 24070-2:2021, sealant identification (name/type/colour/batch), cup dimensions/material, curing climate, measured thickness(es) and any deviations.
Applications and users
ISO 24070-2:2021 is practical for:
- Sealant manufacturers - product development, cure profiling and batch quality control.
- Independent test laboratories - standardized measurement for certification and comparisons.
- Specifiers, architects and contractors - verifying cure performance against project requirements.
- R&D and materials engineers - evaluating cure kinetics and formulation changes.
This method provides consistent, comparable cured thickness data used to assess sealant performance in joints, ensure compliance with specifications and inform application guidance.
Related standards
- ISO 6927 - vocabulary for buildings and civil engineering sealants (normative reference).
- ISO 24070 series - other parts in this series cover complementary test methods and should be consulted where applicable.
Keywords: ISO 24070-2:2021, cured thickness, cylindrical cup test method, one-component sealants, building sealants, sealant testing, thickness calliper, cure duration.