Overview
ISO/TS 16774-2:2023 - Test methods for repair materials for water-leakage cracks in underground concrete structures - Part 2: Test method for chemical resistance specifies a laboratory immersion test to qualitatively determine the chemical resistance of injection-type water‑leakage repair materials. The method evaluates how well a repair material retains its original mass after prolonged contact with water containing aggressive chemical species found in underground environments.
Key Topics and Requirements
- Scope: Applies to injection repair materials used to stop water leakage in concrete cracks in underground structures. Focuses on material behavior when submerged or in contact with chemically active water.
- Principle: Chemical attack is assessed by measuring mass change before and after exposure; greater mass loss indicates weaker chemical resistance.
- Test specimens: Repair material is placed in a glass Petri dish, finished flat, cured to constant mass, and prepared in replicate for repeatability.
- Chemical exposures: Typical chemicals include acids (HCl, H2SO4, HNO3), alkalis (NaOH), salts (NaCl) and other ions (nitrate, carbonate, acetate, sulfate). Concentration and exposure duration are selected to reflect applicable environmental conditions.
- Apparatus: Non‑reactive container (glass/plastic), Petri dishes/plates, electronic scale with 0.01 g resolution, stirring/trowel tools; optionally injection apparatus.
- Ambient conditions: Default test room at (22 ± 2) °C and (55 ± 5) % RH (alternative national ranges noted).
- Procedure: Measure initial mass (Mb), immerse specimen centered in solution for specified time, rinse with distilled water, dry to constant mass, measure final mass (Ma), compute mass change Mc = Mb − Ma and percent mass loss. Photograph specimens at each stage.
- Results & reporting: Report material identification (manufacturer, manufacture date, composition), test conditions (chemical type, concentration, exposure time, ambient), quantitative mass loss and photos. Include any ecotoxicological data if required.
Applications and Who Uses It
- Material manufacturers: Validate and compare chemical resistance of injection repair formulations.
- Testing laboratories: Provide standardized lab procedures for durability and performance testing.
- Design engineers & specifiers: Select appropriate repair materials for underground concrete structures (tunnels, basements, sewers) exposed to aggressive groundwater.
- Contractors & asset owners: Assess long‑term performance of waterproofing repairs and justify material choice under specific chemical exposure conditions.
- Standards committees & regulators: Use as a reference method for national adoption or for creating performance requirements.
Keywords: ISO/TS 16774-2:2023, chemical resistance test, water‑leakage repair materials, underground concrete structures, immersion test, mass loss measurement, injection materials, durability testing.
Related Standards
- ISO/TR 16475 - General practices for the repair of water‑leakage cracks in concrete structures (reference framework).
- Other parts of the ISO/TS 16774 series (e.g., Part 1, Part 5, Part 6) for complementary test methods and performance properties.