Fibre concrete pulled directly, without bending — the first standard of its kind
ISO 13180-1:2026 gives a direct tensile test method for fibre-reinforced cementitious composites that show strain-hardening behaviour. The specimen is loaded uniaxially, without any parasitic bending moment.
- The first edition appeared in May 2026; it covers composites that carry more load after cracking than before it — behaving in the opposite way to ordinary concrete.
- From the stress–strain curve the method derives the first cracking strength, the post-cracking strength, the strain capacity and the number of cracks within the gauge length.
- A valid test requires uniaxial tension without a parasitic bending moment — which calls for grips and alignment more careful than in an ordinary strength test.
- The method is not used for materials showing strain-softening; for those the existing load–deflection tests remain.