Overview
EN ISO 10722:2019 - “Geosynthetics - Index test procedure for the evaluation of mechanical damage under repeated loading - Damage caused by granular material (laboratory test method)” - specifies a laboratory index test procedure to simulate mechanical damage to geosynthetics caused by granular material under repeated loading. Damage is assessed visually and by measuring the loss of tensile strength compared to a reference test. This procedure uses a standard granular material (sintered aluminium oxide) but allows alternative aggregates (see Annex A). It is explicitly an index test and not intended to derive reinforcement reduction factors.
Key topics and technical requirements
- Test principle: specimen sandwiched between two granular layers and subjected to dynamic (cyclic) compression; evaluate visual damage and change in mechanical property (expressed as percent change of a reference property).
- Specimen sampling & dimensions: follow ISO 9862; for tensile testing, prepare five specimens (min. 2.0 m × 0.20 m) then split into damaged and reference halves (min. 1.0 m × 0.20 m).
- Conditioning: standard atmosphere per ISO 554 - typically 20 ± 2 °C and 65 ± 5 % RH - until mass is stable.
- Apparatus:
- Compression machine capable of sinusoidal pressure (approx. 10 ± 1 kPa to 500 ± 10 kPa) at 1 Hz (pre-load typically 5 kPa then cyclic loading).
- Rigid metal test container (minimum 300 mm × 300 mm plan) in two 75 mm deep parts, loading plate (100 × 200 mm).
- Standard granular material: sintered aluminium oxide with particle size such that 100% passes 10 mm sieve and 0% passes 5 mm sieve (periodic wet sieving and replacement rules apply).
- Reference mechanical test: wide‑width tensile testing per ISO 10319 or other agreed reference test to quantify strength loss.
- Reporting: visual damage description and percentage change of the reference property.
Applications
- Comparative evaluation of geosynthetic durability against repeated granular loading (e.g., during construction, compaction, or cyclic traffic loads).
- Product quality control and development (material selection, formulation or manufacturing process comparison).
- Laboratory screening to identify products susceptible to mechanical damage from aggregate contact.
Who should use this standard
- Geotechnical and civil engineers specifying geosynthetic materials
- Materials and QA laboratories performing geosynthetic testing
- Manufacturers developing or verifying geotextiles, geomembranes and geocomposites
- Researchers studying mechanical degradation mechanisms
Related standards
- ISO 10319 - Wide‑width tensile test (reference mechanical property)
- ISO 9862 - Sampling and preparation of test specimens
- EN 933‑1 - Particle size distribution (sieving) for aggregates
- ISO 554 - Standard atmosphere for conditioning and testing
This standard is essential when you need a repeatable, internationally accepted laboratory index test to compare how geosynthetics withstand repeated granular loading.
