Overview
ISO/TS 19708:2007 defines a laboratory test method to simulate mechanical damage to geosynthetics used as separators beneath interlocking‑concrete‑block pavements. Using a roller compactor (the same type used for bituminous mixtures), the procedure reproduces repeated traffic and pedestrian loading on a geosynthetic placed between a cushion sand layer and a base coarse material. Test outputs-principally the retained sand index (RSI) and a visual damage assessment-help select geosynthetic products for pavement separation performance.
Key topics and technical requirements
- Scope: Damage simulation for separator geosynthetics in interlocking‑block pavements to support product selection.
- Specimens & sampling: Specimens sampled per ISO 9862; typical specimen sizes described (cut from 520 mm × 1 040 mm to 520 mm × 520 mm); six secondary specimens tested.
- Conditioning: Standard atmosphere (20 ± 2 °C, 65 ± 5 % RH) per ISO 554 prior to testing.
- Apparatus:
- Roller compactor capable of controlled line pressure, rolling velocity and stroke; minimum line pressure 30 kN/m.
- Roller geometry and motion limits specified (roller radius ~460–480 mm; width 400–500 mm; moving length ≥460 mm).
- Square mould (500 mm side) and rubber backing plate (10 mm thickness, hardness 84 ± 4).
- Aggregates:
- Base coarse: crushed stones, grain size 8–16 mm, Los Angeles abrasion ≤ 20 % (EN 1097‑2).
- Cushion sand: grain size 60 μm–2 mm; both washed and dried.
- Test procedure: Geosynthetic is laid between base and 20 mm cushion sand, interlocking blocks are placed, roller compactor applies repeated loads (specified line pressure and cycles); sand retained above the geosynthetic and sand passing into the base are measured.
- Results:
- Retained sand index (RSI) quantifies sand retention after damage (expressed as a percentage using measured masses before and after testing).
- Visual inspection reports holes or cracks and other damage.
- Reporting: Test reports must reference ISO/TS 19708:2007 and include laboratory details, apparatus, environmental conditions, aggregate description, RSI (mean and individual values), visual observations, deviations and unusual behaviour.
Applications and who uses this standard
- Geosynthetic manufacturers - validate separator resilience and support product datasheets.
- Pavement designers and specifiers - compare geosynthetics for interlocking‑block pavement designs subject to pedestrian and traffic loads.
- Construction and testing laboratories - perform repeatable qualification and quality‑control tests.
- Contractors and asset owners - assess long‑term performance risk of sand migration and joint stability.
Practical keywords: ISO/TS 19708:2007, geosynthetics test method, roller compactor, interlocking concrete block pavement, retained sand index, separator geotextile selection.
Related standards
- ISO 9862 (sampling/preparation of geosynthetic specimens)
- ISO 554 (standard atmospheres for testing)
- EN 1097‑2 (aggregate abrasion/Los Angeles test)
- ISO 7619 series (rubber hardness measurement)