Overview
ISO 13428:2005 - Geosynthetics: Determination of the protection efficiency of a geosynthetic against impact damage - defines an index test method to quantify how well a geosynthetic protects a hard substrate from impact loads. The test uses a hemispherical steel probe to apply a controlled impact to a geosynthetic specimen resting on a rigid support with a thin lead plate between them. The protection efficiency is expressed as the change in lead-plate thickness after impact, corrected for specimen properties.
Key topics and requirements
- Scope and applicability: Suitable for geosynthetics with aperture sizes up to 15 mm and can be applied as an index or adapted for performance testing (Annex A).
- Specimens: Five square specimens per face, minimum 100 × 100 mm, conditioned to the standard atmosphere (20 ± 2) °C, 65 ± 5% RH (ISO 554).
- Apparatus:
- Hemispherical probe with 20 mm diameter head.
- For index tests: probe mass (1000 ± 2) g and falling height (1 ± 0.01) m.
- Rigid specimen support: 40 mm thick steel plate on a non-deformable base.
- Soft lead plate (EN 12588 grade 3) nominal thickness 1.8 mm (discard if outside 1.8 ± 0.2 mm).
- Thickness gauge capable of measuring under 2 kPa with ±0.01 mm accuracy and 0.50 mm rounded contact tip.
- Procedure: Impact each specimen once; measure initial and residual lead-plate thickness at impact locations. A single lead plate may be used for five impacts if appropriate.
- Calculation and reporting: Residual thickness values are corrected for specimen mass per unit area and nominal thickness; results are reported as percent residual thickness. The test report must list apparatus details, specimen data, conditioning, raw measurements, corrections and any departures from the procedure.
Applications and users
ISO 13428:2005 is practical for:
- Geotechnical and civil engineers specifying geosynthetic layers for protective functions.
- Manufacturers and quality-control laboratories evaluating the impact protection efficiency of geotextiles, geomembranes and related geosynthetic products.
- Design teams assessing the vulnerability of underlying hard surfaces (e.g., concrete, metal) to dynamic loading during installation or service.
- Test laboratories developing performance simulations (per Annex A) to reproduce in-situ impact conditions.
Keywords: ISO 13428:2005, geosynthetics, protection efficiency, impact damage, index test, lead plate thickness, probe impact test, geotextile testing, specimen conditioning.
Related standards
- ISO 554 (conditioning atmospheres)
- ISO 9862 (sampling)
- ISO 9863-1 (thickness measurement)
- ISO 9864 (mass per unit area)
- EN 12588 (lead plate specification)
- EN 918 and NF P84-506 (related dynamic puncture/impact methods)
This concise summary helps practitioners understand ISO 13428:2005’s purpose, technical requirements, and typical use cases for evaluating geosynthetic protection against impact damage.