ISO 5091-1:2023

Overview

ISO 5091-1:2023 sets forth the general principles and guidelines for the structural intervention of existing concrete structures using cementitious materials. Developed by the International Organization for Standardization (ISO), this document establishes internationally recognized standards for the design, execution, and maintenance of interventions that aim to restore, sustain, or improve the mechanical performance of concrete structures. It applies to overlaying, underlaying, and jacketing methods, ensuring interventions deliver effective and enduring results. The standard is particularly relevant to sectors focused on infrastructure rehabilitation, repair, and the extension of service life for concrete assets.

Key Topics

• Assessment of Existing Structures: Guidance on detailed investigation prior to intervention, including document review, site inspections, and understanding local conditions influencing materials and methods.
• Intervention Design: Requirements for developing a rational structural plan and detailed reinforcement strategies, taking into account integration with existing structures and long-term performance.
• Approved Methods: Coverage of overlaying (top-surface), underlaying (soffit), and jacketing techniques using cementitious materials, each suited to specific structural scenarios such as bridge decks, tunnels, and columns.
• Materials Selection: Description of quality requirements for cementitious materials, reinforcing materials, bonding products, and filling materials to ensure integrity and compatibility with existing structures.
• Performance Verification: Steps for verifying the effectiveness, safety, durability, and serviceability of interventions, including calculations and analysis to meet target performance levels.
• Execution and Quality Control: Best practices for planning, detailing, construction, and post-completion inspection, ensuring interventions are reliable and sustainable.
• Maintenance and Documentation: Procedures for ongoing maintenance, as well as requirements for keeping records to support the longevity of the repaired or strengthened structures.

Applications

ISO 5091-1:2023 is widely applicable across civil engineering and construction industries, specifically in:

• Infrastructure Rehabilitation: Bridges, tunnels, roadways, and public buildings that require structural upgrade or life extension through overlaying, underlaying, or jacketing with cementitious materials.
• Seismic Retrofit and Strengthening: Enhancing ductility, stiffness, or load-carrying capacity for structures in seismic zones, or increasing resilience against other specific loads.
• Asset Management Programs: Supporting asset owners, designers, and contractors in making informed decisions during repair and maintenance cycles to ensure compliance and optimize investments.
• Post-Repair Performance Verification: Ensuring repairs deliver required mechanical performance, minimize service interruptions, and address safety, durability, and maintainability concerns.

Related Standards

To ensure a holistic approach, ISO 5091-1:2023 should be used in conjunction with other key standards, such as:

• ISO 16311 Series: Comprehensive guidelines on maintenance, repair, design, and execution of repairs for concrete structures.
• ISO 19338: Guidelines for performance and assessment requirements for design standards on structural concrete.
• ISO 10406 Series: Testing methods for fibre-reinforced polymer (FRP) reinforcement of concrete.
• ISO 22966: Guidance for the execution of concrete structures, covering general construction practices.
• ISO 679: Relevant test methods for determining cement strength.

Practical Value

Implementing ISO 5091-1:2023 provides numerous practical benefits for stakeholders:

• Assures Quality and Consistency: Harmonizes intervention practices, ensuring high-quality, reliable, and durable results across projects.
• Risk Reduction: Supports comprehensive assessments and robust designs that mitigate future failures or degradation.
• Facilitates Compliance: Streamlines conformance with global best practices for concrete structural repairs.
• Enhances Asset Longevity: Promotes interventions that extend service life while supporting economic and environmental sustainability.
• Supports Innovation: Encourages the use of proven and emerging cementitious materials and reinforcement techniques suited to local demands.

Adopting ISO 5091-1:2023 is essential for anyone involved in the maintenance, repair, design, or management of concrete structures seeking to achieve international standards of safety and performance.