Overview
ISO/TR 16475:2020 - General practices for the repair of water‑leakage cracks in concrete structures - is a technical report that provides guidance for selecting and applying grout materials to stop water ingress through cracks, joints and other deformities in concrete. It focuses on water‑leakage (wet) cracks, describing conditions that affect repair performance, selection procedures for injection grouts, execution of repair methods, performance assessment and data collection. The document includes a maintenance flow chart (Figure 1) and purposely excludes dry crack repair (see ISO 16311‑4).
Key Topics and Technical Requirements
- Conditions of water‑leakage cracks
- Classification of leakage types (damp, seepage, flow) and crack sizes; example ranges from ISO/TR 16475 include leak rates and crack widths corresponding to fine, medium and large cracks.
- Environmental degradation factors (chemical and mechanical) that influence repair success.
- Performance requirements for repair materials
- Thermal stability, chemical resistance, washout (water flow) resistance, adhesion on wet substrate, watertightness and response to substrate movement.
- Grout material types
- Overview of common grouts: water‑based acrylic gels, cementitious grouts, epoxy resin grouts, polyurethane grouts, synthetic rubber polymer gel grouts and other specialist materials.
- Selection and testing procedures
- A structured selection process for injection grouts with recommended tests for thermal stability, chemical resistance, washout resistance, adhesion on wet surfaces, watertightness and dynamic response.
- Execution and quality control
- Recommended grouting/injection methods, procedures to reform waterproofing layers, and inspection/evaluation criteria for repaired structures.
- Data collection
- Guidance on recording repair materials, test results and performance assessments to inform future maintenance.
Applications
ISO/TR 16475 is practical for:
- Structural and civil engineers specifying rehabilitation works on basements, tunnels, water tanks, bridges and parking structures.
- Contractors and applicators performing injection grouting and waterproofing repairs.
- Asset owners and facility managers planning maintenance strategies to mitigate water ingress and durability loss.
- Testing laboratories developing performance tests for repair materials.
Benefits include improved selection of grout materials, better control of repair quality, reduced rework, and enhanced long‑term watertightness of concrete structures.
Related Standards
- ISO 16311‑2 - Assessment of existing concrete structures (referenced)
- ISO 16311‑4 - Repair of dry cracks (separate guidance)
- ICRI 340.1‑2006 - Crack classification referenced for leakage types
Keywords: ISO/TR 16475:2020, water‑leakage cracks, grout materials, concrete repair, injection grouts, watertightness, washout resistance, thermal stability, leakage classification.