Overview
ISO 15698-2:2012 specifies test methods for headed steel bars used as reinforcement of concrete. It defines how to verify the anchorage performance, head-to-bar connection strength and joint robustness of headed bars through controlled tensile and fatigue tests. The part is intended for qualification testing in relation to reinforced concrete design standards and standards for reinforcing bars. Impact loading tests are excluded from this part.
Key topics and technical requirements
- Load transfer tests
- Methods for testing headed bars embedded in concrete and tested “in air” (head bearing on a plate).
- Verification of head bearing area, anchorage stiffness, head-to-bar connection strength and required additional bond length (Category B1 heads).
- Tests include static anchorage capacity, high-cycle elastic fatigue and low-cycle elastic–plastic loading.
- Joint robustness tests
- Wedge tensile tests and bend tests to check mechanical integrity of head-to-bar connections.
- Specimen and test setup
- Concrete specimens are square prisms with the headed bar cast centrally; dimensions vary with bar diameter (manufacturer specifies concrete strength).
- Confinement reinforcement is required to prevent premature splitting; minimum three specimens per test.
- Measurement and equipment
- Testing machines calibrated per ISO 7500-1 (class 1 or better).
- Force measurement accuracy: ±1%; strain measurement: ±5%; head displacement measured with an extensometer class 1 (ISO 9513).
- Concrete quality, making and curing per ISO 1920-3/4; concrete strength classification per ISO 22965-2.
- Reporting
- Test reports must record specimen geometry, material and surface condition, test procedures and results.
Practical applications
- Qualification and type-testing of headed bars for use in reinforced concrete elements where mechanical anchorage is required (e.g., beam-column joints, terminal anchorage, precast connections).
- Verification of design assumptions about anchorage and composite action between head and bond.
- Support for quality control in manufacturing, product certification, and acceptance testing on construction projects.
Who uses this standard
- Manufacturers of headed steel reinforcing bars
- Independent testing laboratories and certification bodies
- Structural and geotechnical engineers specifying anchorage solutions
- Construction quality inspectors and regulatory authorities
Related standards
Keywords: ISO 15698-2, headed bars, test methods, reinforcement of concrete, anchorage, load transfer tests, head-to-bar connection, fatigue testing.