EN ISO 13438 Geosynthetics - Screening Test Method for Determining the Oxidation Resistance of Geotextiles and Geotextile-Related Products

fEN ISO 13438 Geosynthetics - Screening Test Method for Determining the Oxidation Resistance of Geotextiles and Geotextile-Related Products

The standard “EN ISO 13438 Geosynthetics - Screening test method for determining the oxidation resistance of geotextiles and geotextile-related products,” developed by the International Organization for Standardization (ISO) and later published as a European standard within the scope of harmonization efforts, describes a screening test method for determining the oxidation resistance of geotextiles and geotextile-related products. These methods are applicable to the following products:

• Method A: For materials containing polypropylene (PP), polyethylene (PE), polyamide (PA), and aramid (AR) only.
• Method B: For materials containing polyvinyl alcohol only.

The data is suitable for screening purposes, but not for obtaining performance data such as lifespan unless supported by further evidence.

ISO 13438 is an international standard that provides a screening test method for evaluating the oxidation resistance of geotextiles and geotextile-related products (e.g., geogrids or geocomposites). Oxidation is a significant long-term degradation mechanism, particularly for polymer-based geosynthetics made from polyolefins such as polypropylene (PP) and polyethylene (PE).

Geosynthetics are widely used in civil engineering applications such as the following:

• Soil reinforcement
• Road construction
• Landfill liners
• Erosion control
• Drainage systems

In these applications, materials can be exposed to heat, oxygen, UV light (indirectly), and chemicals for decades. Oxidation can cause chain breakage in polymers, leading to brittleness, loss of tensile strength, and shortened service life. Manufacturers use stabilizers (antioxidants) to slow down this process, and the EN ISO 13438 standard helps verify their effectiveness.

The described test method serves as an accelerated screening method to estimate long-term durability, typically targeting service lifespans of 25, 50, or 100 years.

This standard requires exposing geotextile samples to high temperatures in an oxygen-rich environment to accelerate oxidative degradation. Two main methods are referenced in the relevant standards:

• Method A: This method involves high-temperature oven aging in an air or oxygen environment.
• Method B: Involves evaluating the retention of properties (typically tensile strength or elongation) before and after exposure.

These methods generally follow these steps:

• Preparation of representative samples.
• Incubate at the specified temperatures (e.g., 80-110 degrees Celsius, depending on the polymer and the desired simulation).
• Measuring mechanical properties (e.g., tensile strength according to ISO 10319 or similar standards) after exposure.
• Calculation of the percentage of retained strength.

Common acceptance criteria in specifications (e.g., for reinforcement applications) include maintaining at least 50 percent of the original strength after a defined exposure time.

These methods are applicable to geotextiles and related products. All possible field conditions (e.g., combined chemical or biological attack) are excluded. These methods are screening tests, not full life expectancy tests. They are also often used in conjunction with other durability tests such as UV resistance (EN 12224 standard), hydrolysis, or creep tests.

The industrial applications of this standard are as follows:

• Quality control by manufacturers.
• Product certification and CE marking in Europe.
• Specifications for infrastructure projects.
• A comparative ranking of different geotextile products.

The relevant standards are as follows:

• ISO 13437 Field durability assessment.
• ISO 13439 Hydrolysis resistance screening.

The EN ISO 13438 standard is necessary because geotextiles are commonly used in long-term civil engineering and environmental applications such as road construction, drainage systems, embankments, landfills, erosion control, and tunnels. Many of these products are made from polymers such as polypropylene or polyester, which can degrade over time when exposed to oxygen, heat, and environmental aging. The main reasons why this standard is considered important are as follows:

• Evaluates long-term durability: Geotextiles are expected to perform underground or in infrastructure systems for years or even decades. Oxidation can cause the polymer chains to break down, leading to:
  • Loss of tensile strength
  • Fragility
  • Cracking
  • Decreased filtration or separation performance.

This standard provides a screening method to estimate how resistant a material is to oxidative aging prior to installation.

• It supports material selection: Manufacturers, engineers, and specifiers use this test method to compare different geotextile formulations, stabilizers, and additives. Products with better oxidation resistance are better suited for the following demanding applications:
  • High temperature environments
  • Chemically aggressive soils
  • Landfill liners and covers
• It improves infrastructure reliability: Replacing a faulty geotextile in a road, retaining wall, or drainage layer is neither easy nor inexpensive. Premature deterioration can lead to:
  • Drainage failure
  • Soil mixture or imbalance
  • Structural settlement
  • Erosion problems

Testing oxidation resistance helps mitigate these risks early in the design phase.

• Quality control and compliance: This standard provides manufacturers and testing laboratories with a consistent methodology, meaning results are more comparable across countries, suppliers, and projects. This is beneficial for:
  • Procurement specifications
  • certification
  • Regulatory compliance
  • Customer trust
• Screening stabilization efficacy: Many polymer geotextiles contain antioxidants to slow oxidation. This standard helps determine whether these stabilizers are sufficiently effective in protecting the product throughout its service life.

In short, the EN ISO 13438 standard is necessary because it helps ensure that geotextiles remain durable and functional for a long time by evaluating their resistance to oxidation, a major cause of polymer degradation in civil engineering applications.

In conclusion, the EN ISO 13438 standard provides a practical and standardized way to evaluate how well geotextiles will withstand oxidative aging over long service lives. By using accelerated thermal-oxidative exposure, engineers and specifiers can make informed decisions about material selection for critical geotechnical applications where long-term strength retention is essential.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with the EN ISO 13438 standard.