Overview
ISO 29469:2022 - Thermal insulating products for building applications - Determination of compression behaviour - defines the equipment, specimen preparation and test procedures to measure the compression behaviour of thermal insulation used in buildings. The method determines compressive strength, compressive stress at 10% strain, and compression modulus of elasticity for short‑term loads and as input to compressive creep tests. It is intended for quality control and to produce reference values that can be converted to design values using safety factors.
Key topics and requirements
- Scope: Applies to thermal insulating products exposed to short‑term compressive loads and for use in compressive creep testing.
- Apparatus: Rigid compression testing machine with polished, parallel platens; continuous force and displacement measurement and recording. Permissible errors: displacement ±5% or ±0.1 mm, force ±1%.
- Specimen dimensions & preparation:
- Specimens retain original product thickness; width ≥ thickness.
- Standard square sizes (50×50 mm up to 300×300 mm) or as specified in product standards.
- Parallelism/flatness tolerance ≤ 0.5% of side length or 0.5 mm.
- Cutting and preparation must not alter product structure; skins retained if integral.
- Conditioning & test environment:
- Typical conditioning: (23 ± 5) °C; in disputes: (23 ± 2) °C and 50 ± 5% RH.
- Tropical option: (27 ± 2) °C and 65 ± 5% RH - must be reported.
- Test procedure:
- Preload typically 250 ± 10 Pa (50 Pa allowed for very deformable materials).
- Compression rate: constant displacement = 0.1 × specimen thickness (d) per minute (±25%).
- Continue until yield/rupture (report compressive strength and corresponding strain) or until 10% strain (report compressive stress at 10%).
- Force‑displacement curve recorded for additional analysis (e.g., modulus).
- Results & calculations:
- Results reported as mean values (three significant figures).
- Compressive strength computed from maximum force divided by initial cross‑sectional area; compressive stress at 10% strain and compression modulus are derived per the standard.
- Special cases: Annex A provides modifications for cellular glass products (including capping in the protocol).
Applications and users
- Who uses it: manufacturers of thermal insulation, independent test laboratories, product certification bodies, building designers, and specifiers.
- Practical uses:
- Routine quality control and batch verification.
- Input data for structural and thermal design where insulation experiences compressive loads (e.g., under floor screeds, bearing pads).
- Reference data for compressive creep testing and for establishing safe design values.
Related standards
- ISO 5725-2 - Accuracy (trueness and precision) of measurement methods.
- ISO 29768 - Determination of linear dimensions of test specimens.
Keywords: ISO 29469:2022, thermal insulating products, compression behaviour, compressive strength, compressive stress, compression modulus, compression testing machine, building applications, quality control.
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