Overview
ISO 13438:2018 - Geosynthetics: Screening test method for determining the resistance of geotextiles and geotextile-related products to oxidation (ISO) specifies accelerated screening tests to evaluate how geotextiles resist oxidative degradation. The standard covers two methods: Method A for polymers based on polypropylene (PP), polyethylene (PE), polyamide (PA) and aramid (AR), and Method B for poly(vinyl alcohol) (PVAL). Results are intended for screening and comparison - they are not by themselves a basis for guaranteed service life unless supported by additional evidence.
Key topics and technical requirements
- Scope: Applies to geotextiles and geotextile-related products composed solely of the named polymers.
- Acceleration mechanisms:
- Method A: Temperature-driven acceleration. Specimens are leached in water at (80 ± 1) °C for 28 days then oven-aged in air at (100 ± 1) °C for durations related to target service lives (e.g., 28, 56, 112 days for 25, 50, 100-year screening scenarios).
- Method B: Used for PVAL; combines moderately elevated temperature with increased oxygen concentration (oxygen overpressure in a pressured vessel/autoclave) - typical first-evaluation exposure is 28 days.
- Specimen handling and reproducibility:
- Products manufactured ≥24 h before testing; specimens from the same recipe tested together.
- Specimens suspended freely and spaced in ovens/autoclaves; oven airflow of 3–10 air changes/hour recommended (higher accepted and noted).
- Control specimen leaching: 6 h in water at 80 °C + 6 h in oven at 100 °C.
- Performance measurements:
- Post‑exposure mechanical properties measured by tensile testing per EN 12226 (tensile strength and strain at maximum load).
- Minimum of five test and five control specimens per relevant direction (machine and cross-machine) unless otherwise agreed.
Applications and who uses it
- Practical for manufacturers, QA/QC laboratories, material engineers, geotechnical designers, specifiers and procurement teams who need comparative data on oxidation susceptibility of geotextiles.
- Commonly applied in civil-engineering contexts where geosynthetics contact soil moisture and oxygen (landfills, embankments, drainage layers, erosion control).
- Useful for screening candidate materials, verifying stabilizer effectiveness, and supporting material selection in long-term soil environments.
Related standards (references)
- EN 12226 - General tests for evaluation following durability testing (tensile test procedures).
- ISO 3696 - Water for analytical laboratory use (Grade 3 water specification used in leaching).
- ISO 1043-1 - Polymer designation (reference for PVAL identification).
Keywords: ISO 13438:2018, geosynthetics, geotextiles, oxidation resistance, screening test, polypropylene, polyethylene, polyamide, poly(vinyl alcohol), tensile testing, EN 12226.