Overview
ISO 12960:2020 - "Geotextiles and geotextile-related products - Screening test methods for determining the resistance to acid and alkaline liquids" - defines accelerated, laboratory screening (index) tests to assess how geotextiles and related products resist acidic and alkaline aqueous environments. The standard is intended for use with ISO/TS 13434 (durability assessment) and replaces earlier guidance (ISO/TR 12960:1998 / EN 14030:2001). It provides reproducible immersion test procedures, not lifetime predictions; results must be interpreted in the context of site conditions.
Key topics and technical requirements
- Scope: Applicable to all geotextiles and geotextile-related products; tests exclude external mechanical stress and assume specimens are fully immersed.
- Two methods:
- Method A: Designed particularly for polyamides - uses an inorganic acid test liquid (0.025 M sulfuric acid with 1 mmol ferri- and 1 mmol ferro-sulfate).
- Method B: applies to polyesters and polyamides - uses inorganic alkaline liquid (saturated calcium hydroxide ≈ 2.5 g/L).
- Test conditions:
- Temperature: 60 ± 1 °C
- Duration: 3 days
- Liquid volume: >30 × mass of specimens, complete coverage
- Specimen spacing: at least 10 mm from other specimens, vessel walls and liquid surface
- Number of specimens: five test specimens and five control specimens (controls immersed 1 h in water at same temperature)
- Apparatus & handling: corrosion-resistant vessels (borosilicate glass or stainless steel), stirring/air saturation to maintain homogeneity, light shielding, and routine monitoring/replenishment of test liquid to maintain composition and pH.
- Post-test cleaning and evaluation:
- Rinse sequence: water → 0.01 M sodium carbonate → water
- Special cleaning for polyester exposed to Ca(OH)2 to remove calcium terephthalate (trisodium NTA and acetic acid rinses)
- Drying (≤60 °C) and property changes evaluated per EN 12226
Applications and users
ISO 12960 is used for:
- Manufacturers of geotextiles and geosynthetics for quality control and material selection
- Independent testing laboratories performing chemical resistance screening
- Design engineers, specifiers and asset owners assessing suitability of geotextiles for contaminated sites, landfill liners, drainage filters, coastal works, tunnels and infrastructure where exposure to acidic/alkaline liquids is possible
- Regulatory bodies and procurement teams requiring standardized chemical resistance data
Note: ISO 12960 provides screening data to inform selection and further testing; it does not replace long-term performance studies under mechanical stress and real site conditions.
Related standards
- ISO/TS 13434 - Guidelines for assessment of durability (use in conjunction)
- EN 12226 - General tests for evaluation following durability testing (property change evaluation)
- ISO 3696 - Water for analytical laboratory use (reagents)