Overview
ISO/TS 16774-3:2023 is a technical specification from ISO that defines a laboratory test method for water (wash out) resistance of repair materials used to stop water-leakage cracks in underground concrete structures. The method quantifies how well grouting and injection materials resist erosion and washout when exposed to continuous underground water flow by measuring mass loss before and after exposure.
Key topics and requirements
- Test principle: Evaluate washout resistance by comparing specimen mass before (Mb) and after (Ma) exposure to controlled water flow; mass change (Mc = Mb − Ma) and percentage mass loss are used to rate performance.
- Specimen preparation: Repair material is placed in a glass Petri dish (surface leveled) and cured to constant mass under controlled ambient conditions.
- Ambient conditions: Default laboratory conditions are (22 ± 2) °C and (55 ± 5) % relative humidity unless national standards require different values; drying to constant mass follows ISO 1920‑8 practice.
- Apparatus: Key equipment includes a water flow chamber capable of maintaining constant flow velocity, glass Petri dishes, an electronic scale (two decimal places in grams), non‑woven fabric filters (to collect eroded particulates), and standard placement tools.
- Procedure: Record specimen condition and Mb, cover with non‑woven fabric (not touching the material surface), expose to predetermined water flow (velocity and duration per national practice), dry to constant mass, record Ma, compute Mc and percentage loss. Photograph stages for traceability.
- Expression of results and reporting: Results are reported as absolute and relative mass loss. Test reports must include detailed specimen, material, test conditions and a technical declaration of conformity to ISO/TS 16774-3:2023. Manufacturer data, curing, equipment, and any deviations are recorded.
Applications and who uses this standard
ISO/TS 16774-3:2023 is intended for practical use by:
- Materials manufacturers developing or certifying injection grouts and repair compounds for underground concrete repairs.
- Testing laboratories performing standardized durability and washout resistance testing.
- Civil/structural engineers, contractors and repair specialists selecting repair products for tunnels, basements, sewer systems and other subterranean concrete structures subject to groundwater flow.
- Asset owners and infrastructure managers who need objective data to compare repair materials and specify performance requirements in procurement.
- Standards bodies and regulators adopting or adapting test parameters to national codes.
This TS supports objective comparison of washout resistance and helps inform selection of repair materials that resist erosion under sustained water flow.
Related standards
- ISO/TR 16475 - General practices for the repair of water‑leakage cracks in concrete structures (provides background and property definitions).
- ISO/TS 16774 series - Companion documents that cover other test methods for repair material performance.