Overview
ISO/TS 16774-6:2024 defines a laboratory test method to evaluate the substrate (crack) movement response of repair materials used for water-leakage cracks in underground concrete structures. The method pairs a cyclic substrate movement (tensile/compressive) test with a subsequent permeability (water-tightness) test to determine whether injected repair materials retain waterproofing performance after simulated crack movements. The Technical Specification provides general principles and procedures; specific test parameters (cycle width, number, pressure, ambient conditions) are to be completed using relevant national standards or testing protocols.
Key topics and technical requirements
- Test principle: Inject repair material into a specimen with an artificial crack, subject it to repeated tensile/compressive cycles, then assess water permeability.
- Test specimen: Two flat cylindrical concrete/mortar parts assembled with spacers to form an artificial crack. Typical mix proportion noted: water : cement : fine aggregate = 1 : 2 : 6 (mass ratio). Pinholes (Ø 2.5 mm) are drilled to monitor leakage during injection and testing.
- Apparatus:
- Substrate movement apparatus - a Universal Testing Machine (UTM) capable of cyclic tensile/compressive motion.
- Air compressor - capable of delivering approx. 0.1 to 0.3 N/mm² (as a reference in this document).
- Permeability test chamber - capable of handling water pressure in the same approximate range (output method).
- Ambient conditions: Standard drying/shrinkage conditions recommended at (22 ± 2) °C and (55 ± 5) % RH, with allowances for national variations.
- Procedure:
- Inject repair material into the artificial crack following manufacturer or national procedures.
- Run substrate movement cycles to simulate thermal movement, settlement, or vibration.
- Perform permeability (water-tightness) test and record leakage observations.
- Reporting: Test reports must document repair material details, specimen preparation, test apparatus, cycle parameters, pressures used, ambient conditions and photographic records (see clauses 8–9).
Applications and practical value
- Provides a standardized laboratory method for comparative evaluation of injected repair materials (e.g., urethane, polyurea, synthetic grouts) under simulated crack movement.
- Useful for product development, quality control, third‑party testing, and specification of repair materials for tunnels, sewers, basements and other underground concrete structures.
- Helps classify materials into families by movement tolerance and retained impermeability after dynamic substrate behaviour.
Who should use this standard
- Repair material manufacturers and R&D teams
- Independent testing laboratories and conformity assessors
- Structural and geotechnical engineers specifying waterproofing repairs
- Contractors performing injection remediation and QA/QC
Related standards
- ISO/TR 16475 - general practices for repair of water-leakage cracks
- ISO/TS 16774 series (other parts addressing artificial cracks and additional test methods)
- ISO 1920-8 referenced for standard drying/shrinkage conditions
Keywords: ISO/TS 16774-6:2024, substrate movement test, permeability testing, water-leakage crack repair materials, universal testing machine, underground concrete structures.