Overview
ISO 5014:2025 specifies a laboratory method to determine the modulus of rupture (MOR) of dense and insulating shaped refractory products at ambient temperature. The test uses a three-point bending procedure with a constant rate of increase of stress and is applicable to standard-shaped bricks, special shapes and pre-cast products. It can also be applied to unshaped refractories after specimen preparation in accordance with ISO 1927-5 / ISO 1927-6.
Key topics and technical requirements
- Test principle: Bend a prismatic test piece in a three-point bending jig until failure; determine MOR from the recorded peak load.
- Apparatus: Three-edge loading jig (two supports and one central load), testing machine capable of constant loading rate and peak-load recording. Machine accuracy required to ISO 7500-1 Grade 2 (±2%).
- Specimen preparation: Test pieces are taken from items or cut to required dimensions; pressing direction should be recorded. Dry to constant mass (normally (110 ± 5) °C; for MgO-containing products (150 ± 10) °C).
- Dimensions and tolerances: Standard sample sizes are specified (examples in the standard: 230×114×76 mm; 230×114×64 mm; 200×40×40 mm; 150×25×25 mm) with defined span and bearing-edge radii to minimize test-method error.
- Measurement tools: Callipers to ISO 13385-1 resolution (0.1 mm) or equivalent.
- Data reporting: Report mean MOR and standard deviation. The standard includes an informative annex on precision and bias and emphasizes cautious interpretation due to brittleness and scatter in refractory strength.
- Significance: Results assume linear-elastic bending and homogeneous isotropic behavior; comparisons require consistent test conditions (geometry, specimen orientation, loading rate).
Applications and users
ISO 5014:2025 is used for:
- Quality control and batch acceptance testing for refractory brick and shaped products.
- Material development and R&D to compare formulations or processing methods.
- Manufacturing process control to monitor product strength and consistency.
- Design data acquisition for engineers specifying refractory components where bending strength at ambient temperature is relevant.
Primary users include refractory manufacturers, testing laboratories, materials engineers, procurement teams and standards/QA professionals.
Related standards
Keywords: ISO 5014:2025, modulus of rupture (MOR), refractory bricks, three-point bending, shaped refractory products, ambient temperature testing, test jig, ISO 7500-1, ISO 13385-1.