ISO 16311-4:2024

Overview - ISO 16311-4:2024 (Maintenance and repair of concrete structures - Part 4: Execution of repairs)

ISO 16311-4:2024 defines requirements for the on-site execution of repairs to concrete structures. It covers substrate condition before and during application, structural stability, storage and handling of materials, preparation and application of repair products and systems, and measures for quality control, personnel qualifications, maintenance, health, safety and environmental protection. The second edition updates and clarifies references and editorial matters and is part of the ISO 16311 series on maintenance and repair of concrete.

Key technical topics and requirements

• Structural stability during works - Maintaining safety and stability before, during and after repair in line with ISO 16311-3.
• Substrate preparation - Cleaning, roughening, removal of unsound concrete and preparation of reinforcement (cleaning, coating or replacement where necessary).
• Repair methods - Requirements for bonding, hand-applied mortars and concretes, sprayed repair mortar/concrete, cast repair materials, anchoring, plate bonding and fibre-reinforced polymer (FRP) strengthening.
• Curing and wet-on-wet applications - Considerations for curing times and compatible successive layers.
• Defects from reinforcement corrosion - Procedures for coating, removal or replacement of corroded reinforcement and addressing chloride-induced or carbonation-induced deterioration.
• Quality control and testing - Site tests and observations, test specimen handling and performance checks referenced to standards such as the ISO 1920 series for concrete testing.
• Personnel, HSE and environment - Qualifications of applicators, safety procedures, storage of materials and environmental protection during remedial works.
• Electrochemical methods - Recognition of methods such as cathodic protection, re-alkalisation and chloride extraction as part of repair options (listed in the introduction).

Practical applications - who uses ISO 16311-4:2024

• Structural and repair engineers specifying and designing remedial works.
• Contractors and specialist applicators executing concrete repairs, surface preparation and placement of repair systems.
• Asset owners, facility managers and inspectors developing maintenance plans and quality plans for repairs.
• Test laboratories and QA personnel performing site verification and acceptance testing.
  Use cases include bridge deck repairs, concrete façade remediation, marine and infrastructure repairs, and refurbishment of reinforced concrete elements.

Related standards and references

Relevant documents cited include ISO 16311-1, ISO 16311-2, ISO 16311-3, the ISO 1920 series (testing of concrete), ISO 22966 (execution of concrete structures), ISO 5091 (structural intervention), and standards on coatings and surface preparation (ISO 4624, ISO 8501 series). These provide complementary guidance for design, testing and execution.